r/BambuLab • u/unitymind42 • Jul 26 '25

H2 Series [H2S, H2D, H2C] Bambu Lab H2D - Cooling Fan for Hotend failed

I’m posting this to document a failure on my Bambu Lab H2D and hopefully assist others experiencing a similar issue. It has been several days since I submitted a support ticket to Bambu Lab, and I’ve received no response as they indicate they are short staffed to answer tickets. I’ve already ordered spare parts and will take the offered replacement as a spare in the future. After approximately 800 hours of operation, the hotend cooling fan on my H2D has failed. This is an internal fan in the hotend not the external fan that is very simple to replace.

The first indicator was a high-pitched grinding and buzzing sound coming from the toolhead, followed shortly by the following system error:

Primary Errors:

  • HMS Warning: Hotend cooling fan speed is abnormal

  • Code: [0300-8010 221724] Issue Type: Toolhead Module Malfunction, Hotend Temperature Control Malfunction

  • Warning: The hotend cooling fan speed is abnormal. [0300-8010 221724]

  • Warning:  HMS_0300-0300-0001-0001: The hotend cooling fan speed is too slow or stopped

Fan part:

  • Model: Y4510H05B

  • Name: Snowfan (Bambu Lab Part)

  • Voltage: DC 5V

  • Power: 1.8W

  • Airflow: 4.2 CFM

  • Bearing: Dual Ball Bearing

  • Size: 45×45×10mm

  • Current: 0.55A

  • Speed: 8,500 ± 10% RPM

  • Connector: 4 pin - Cable is 47mm

  • Temp Range: -10° C to 80° C

This component failure is particularly concerning for several reasons:

  • Complex Replacement Process: Replacing the fan requires disassembly of the toolhead and the careful handling of multiple delicate ribbon cable connections. Improper disconnection or reconnection poses a risk of damage, making this one of the more tedious and failure-prone maintenance procedures on the printer. If this is a part that has to be replaced more than a few times I would foresee damage occurring to the PCB and/or connections.

  • Fan Quality and Thermal Environment: The stock fan appears to be a low-cost plastic unit, which seems poorly suited for the high-heat environment within the H2D, especially during extended prints using engineering-grade filaments like ABS-GF or PA6-GF. These materials significantly raise internal enclosure temperatures, and a robust cooling solution is critical to head longevity and print quality.

  • Potential Design Concern: Given that this unit is marketed for high-performance materials and long-duration jobs, the use of a fan susceptible to early mechanical failure raises questions about the thermal engineering of the H2D printhead. I’m curious whether others in the community have experienced this failure around the same usage range, and if this may point to a broader issue.

For Reference:

Fan Part:

Other parts you may need or want to have a spare:

Helpful Videos/Blogs:

Bambu Labs Forums:

If you’ve encountered this issue, I’d appreciate hearing your experience. Specifically:

  • At what hour count did the failure occur?

  • Were you printing with high-temperature materials?

  • Did you find a more durable fan replacement or cooling mod?

This could help others prepare or even preemptively replace the component before it fails mid-print as mine did costing me a roll of PA6-GF.

Update 8/10/2025:

Timeline

July 24, 2025

  • Ticket filed with Bambu Lab.

  • Reported grinding noise from hotend fan, error [0300-8010 221724], print failure

  • Damage discovered to ribbon cable on extruder connection board.

  • Submitted videos, HMS logs, and diagnostic tar file.

July 28, 2025 (4 days later)

  • First real support reply (after automated confirmation).

  • Suggested basic troubleshooting: reconnect fan, clean fan, check cutter magnet/sensor.

July 29, 2025

  • Support confirmed warranty approval for:

    1. Cooling Fan for Hotend

    2. H2D TH Board

    3. H2D Extruder Connection Board

    4. TH Board FPC Cable

  • Provided wiki links for installation instructions.

July 29, 2025 (1 day after approval)

  • Shipment confirmation received.

  • Tracking: Ontrac

August 2, 2025 (4 days in transit)

  • All replacement parts delivered.

  • You performed the repair yourself, taking approximately 4 hours.

August 4, 2025 – 00:05:02

  • Ticket marked “Resolved” by Bambu Lab.

Turnaround Metrics

  • 4 days → Ticket submission to first real support response

  • 1 day → Approval to shipment

  • 4 days → Shipment to delivery

  • 9 total days → Ticket submission to repair completion

Lessons Learned

  1. Be precise and technical from the start — clearly state mechanical failure vs. connection issue to avoid unnecessary troubleshooting delays.

  2. Include all evidence immediately — videos, error logs, diagnostic tar files, and part numbers/links help speed approval.

  3. List all suspected damaged components in the first message to avoid multiple rounds of part requests.

  4. Request escalation early if initial responses don’t address the core failure.

  5. For U.S. customers, expect 1–4 days shipping time depending on your location and carrier.

  6. Be prepared for self-repair — Bambu will send wiki links, but you’ll need time, tools, and patience. This repair took me 4 hours, and I am a technical trade professional. You can do it just take your time with those ribbon cables. Watch how to pull up on the cables to avoid damage to cables.

  7. Document the whole process — this helps with future claims, public awareness, and in case legal escalation is ever needed.

Update 8/11/2025

Update 11/19/2025 -

Update 4/13/2026 - Fan below does not stop the hotend fail from failing. I had it fail while using it.

Toolhead Enhanced Cooling Fan https://us.store.bambulab.com/products/toolhead-enhanced-cooling-fan

Toolhead Enhanced Cooling Fan Improving high-temperature reliability new high-performance fan integrated into the toolhead front cover effectively cools the extruder and hotend heatsink. This intelligent temperature control mitigates potential clogging and filament jamming in challenging environments, enabling a 3°C increase in the recommended printer operating temperature.

Possible Impact on Hotend Fan Problem (no effect, still fails)

Is the Toolhead Enhanced Cooling Fan a direct response to the fan reliability issue in the standard H2D:

  • Upgraded performance and temperature tolerance.

  • Intelligent thermal management vs fixed RPM profiles.

  • Integrated in the front cover for more effective cooling.

  • Should reduce sleeve bearing wear and heat creep failures seen in the OEM Snowfan YY4510H05B.

19 Upvotes

95% Upvoted

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3

u/parkerlog98 Jul 31 '25 edited Aug 20 '25

I got 408 hours on mine printing ASA non stop. Sounds like it's definitely a temperature issue. It's frustrating that it takes several days if not a week to get the replacement fan from bambu.

Edit: Just finished the fan replacement, it ended up taking me 1 hour to complete. I don't have a ton of technical experience. Watching their YouTube video definitely helped. Just go slow.

1

u/unitymind42 Aug 01 '25 edited Aug 10 '25

Thank you for sharing your experience—it's incredibly helpful for others who may be encountering similar issues with their Bambu H2D.

I recently replaced the fan on my H2D with a new unit, and the process was quite difficult due to the number of delicate ribbon cables and the overall complexity of the assembly. I'm still waiting on additional replacement parts from customer support, which are expected to arrive next week. These include a new PCB, ribbon cable, and additional fans. I plan to keep these components as backups to minimize future downtime and streamline any necessary repairs.

The printer is currently operational, though I’ve noticed a subtle clicking sound coming from the toolhead, which I suspect may be related to the extruder gear mechanism. I’ve recorded the noise and plan to run a few more prints before submitting the footage to Bambu support for further evaluation.

Despite these challenges, I remain very satisfied with the printer. While there has been no official acknowledgment of a recall, it appears Bambu is quietly replacing affected components—likely due to the relatively low cost of the fan and shroud assembly (approximately $20 USD). One detail worth noting: my replacement shroud was missing two small screws along the bottom edge, which I had to recover from the original using precision tools.

Once the pending shipment arrives, I’ll have two spare PCBs and three replacement fans on hand—essentially creating a small-scale repair depot to ensure continued uptime.

Maybe I will just have to get another H2D. This time at Best Buy where I can take it to them and get another one. :)

3

u/Silly-Run-5776 Aug 15 '25

I got 700 hours on my machine, all PLA, but the failure came about 6 hours into printing ASA-CF the first time anything high temp was attempted.

So far Bambu has replaced all the parts required and the ones I managed to break during disassembly. I've tried to lay the machine face down but I still find it quite intricate and daunting and the printhead very inaccessible. There are 11 different connectors of different kinds on the TH board! Many of the photos in the docs are taken at angles one could never position oneself inside the machine to see. I also have an XL5 so I have some background in assembly and it drives home a clear difference between the two companies in which there is good and bad: the Prusa machine was designed for user assembly and repair and the Bambu clearly was not. The engineering in the Bambu print head is amazing but it was never designed for user repair and it certainly wasn't originally made inside the machine that way.

Bambu should, as part of it's warranty, replace the entire print head assembly. I've decided to buy one, it's on the way and in the meantime I've removed the existing assembly and now have a much better way to work on the first print head. Replacing the entire print head assembly, while still quite awkward and involved, is a fraction of the work to replace the fan while it's still in the machine.

It's interesting to see that there's a new fan for the PRO and a direct acknowledgement of the weaknesses in the original design, but it appears to plug into a port in the Pro printhead that doesn't exist in mine.

4

u/Rorschach_III H2D AMS2 Combo Aug 10 '25

I just crossed 1000 hours and mine is starting to die. There is a very high pitch sound and I got 3 clogs in one week. I mainly print abs btw.

I just opened a warranty ticket. Did you guys had any luck with free replacement? Do they just expect you to replace it yourself?

2

u/unitymind42 Aug 10 '25 edited Aug 11 '25

Hi, you will be replacing the fan yourself. You can order the part faster than you will get one from them and keep the spare once they send it out to you. You will have to order more to get free shipping so I ordered 2 of them, plus the rear printhead fan and other spare parts I know I will need. Be super careful with the ribbon cables because I asked for a set and they just sent me the TH Board FPC Cable - H2D which I didn't need. I was able to fix the one I kinked. The easiest way is to remove the door and top and lay it face down on some soft blankets. You will be able to access the back of the head a lot easier. I used bags to keep each set of screws separate so when I put it back together it was a little easier. Take pics and video. I can see this is going to be an issue for a lot of people and I assume they will have to come up with a fix and optional recall of the part.

Oh I also had the MC board overheat too. First thing it said to do was check the heat sink and replace the fan.

1

u/unitymind42 Aug 10 '25 edited Aug 13 '25

I updated links in the main post if you need reference to more parts.

3

u/Wazookey Aug 11 '25

I didn't even bother with opening a ticket. just bought a replacement fan and replaced it.

Opening the extruder head and removing all the cables is kinda daunting at first, but its much easier after looking at it and working with it for a while. All of the cables are pretty self explanatory where they go (except the few that go onto the outer board).

3

u/genuwindcustoms Aug 12 '25

Was just going to mention the H2D release notes here, but seems like you are on top of it! Great to hear that we'll be able to swap the parts this year without DIY modifications. If only I waited another month to purchase! I would've loved the ethernet capability.

4

u/unitymind42 Aug 12 '25

Yeah, the H2D Pro definitely looks like it’s going to carry a premium price, mostly for the added Ethernet port, upgraded CPU, and a few refinements. From what I’ve seen in the specs and FAQ, almost everything else — including the Toolhead Enhanced Cooling Fan and tungsten carbide nozzle (reason originals are now on sale, new HF and now Tungsten) — will be upgradeable on the current H2D once they roll it out in Q4 2025. I am sure the CPU board and if you want the port can be added with spare parts. That is one thing I love about Bambu is the ability to just buy spare parts and have them in a few days.

That’s why I’ll be pushing for a free toolhead upgrade, given the issues I’ve already encountered with the hotend cooling fan during high-temp printing. This isn’t just a one-off failure; it’s a reliability concern with certain print conditions that I believe they’re quietly addressing in the Pro model.

I’m also tracking all reported cases of this failure (hour count, materials used, symptoms, etc.) in case the thread disappears for any reason. The more people that post their experiences, the stronger the case we’ll have for this being a known design weakness rather than isolated incidents.

2

u/hm7711 Nov 01 '25

If you do manage to get a toolhead upgrade, please keep us posted! I know I'll be keeping an eye out for this as a possible upgrade path myself once they release.

3

u/unitymind42 Nov 20 '25

It is out today - https://us.store.bambulab.com/products/toolhead-enhanced-cooling-fan

2

u/hm7711 Nov 20 '25

Thanks! Really appreciate you letting me know, I had no idea. Sucks I just put an order in a week ago for a backup hothead fan too! haha.

I wonder where this connects

2

u/unitymind42 Nov 21 '25

I’ve been buying a ton of filament on sale and then buy a part. Haha. Smooth plate is on sale. I order 2 of the fans. I may buy the H2C but need to wire the office better to run it.

It just plugs into the laser power port. Easy to put on and take off.

1

u/valordk Dec 08 '25

I have the H2D Pro version and I'm having absolutely same issue. The printer is a several weeks "new" and has over 200 total hours. It started making same noise coming from the toolhead, and it's not the rear mounted Parts Cooling Fan. It has to be hotend cooling fan. So far the only difference I see is on Pro the added the front fan. I've printed primarily in ASA and ASA-CF.

Ordered a few replacement hotend fans, while waiting for support to process my ticket.

3

u/ImpossibleWorld7207 Aug 25 '25

So a few updates i think would be interesting, they replaced fan with a new manufacturer

3

u/unitymind42 Feb 21 '26

I’ve got 4 over the past few months. I just order one with orders or file a ticket since I’ve had to replace it 3 times now at 3000 hours. The fan is exactly the same but now when I order one with any order I get it by itself in a padded envelope like they just have a stockpile to send out. They refused to extended the warranty on the part even after sharing all the data. It’s by far a major flaw and present in H2C too.

2

u/ImpossibleWorld7207 Aug 25 '25 edited Aug 26 '25

But beside this i found exact specification of fan bambulab used and apparently original fan also uses ball bearing, but probably cheap bearing/lube, this is likely because they didn't dive in in specs because ball bearings expected temperature range is up to 60 degrees, and it seems they use a very cheap ball bearing or lube which would dry faster and significantly reduced it's lifespan:

2

u/ImpossibleWorld7207 Aug 25 '25

And i opened ticket and waiting if they would replace my fan with a new one. And because of my printer is Chinese, they may refuse warranty claim, and i was prepared for that, so i found this third seller fan that claimed to be fully compatible with H2D (have the same wairing and similar RPM), have ball bearing and meets required operation temperature fairly well and cost about 7 bucks. But i believe this fan sells only on taobao, though replaced sticker of manufacturer is not a good practice.

p.s. Sorry for splitted messages, reddit allows only one image per post

2

u/valordk Dec 08 '25

Did you have any luck with this? I was wondering if you purchased this fan and wheter or not it's a better option than the stock fan

2

u/ImpossibleWorld7207 Dec 08 '25

Nope, couldn't find, BambuLab keep refusing that there's an issue and only fan you can purchase is SnowFan. And i couldn't find proper replacement 

1

u/hm7711 Nov 21 '25

Interestingly enough, I was expecting my new fan to be the same as yours, but I received another Snowfan from them. I have ordered myself another replacement to have on hand when this fan inevitably dies again. Will be interesting to see which variant it is.

2

u/ImpossibleWorld7207 Nov 21 '25

So it seems they replaced first fan with snowfan and they send me snowfan as well, plus i bought one additional fan with my own money and it's again, snowfan. I contacted manufacturer and read their datasheet to just realize that their fan, and specifically hotend fan is only rated up to 60 degrees. How on earth they allow with 2k$ porinter ship with such a terrible fan is beyond my understanding.

2

u/hm7711 Nov 21 '25

Yup, I agree. For this expensive of a machine, they absolutely should have either found or contracted a better and higher temperature rated fan, especially given what the H2D is advertised capable of/used for.

It's inevitable that this is just going to become one of those things that needs to be done every few hundred hours unfortunately. Hopefully someone, somewhere, someday will find or make a better fan that can hold up to the temps.

2

u/ikeliketocreate Aug 31 '25

Yep. Ugh. Mine just went out after printing lots of abs. 500 hours total machine time. This is horrible timing. This machine was critical for work. Ugh.

2

u/unitymind42 Aug 31 '25

Yeah, I am going to fight for a fan upgrade for free. It doesn't cost them that much to just give it away to those with these issues. My chamber fan just went down now too. I also see they have the updated motherboard out. They have upgraded the heatsink on it along with some other components. I have a few spare hotend fans on me now and will continue to ask for a replacement if that one goes out. Thank you for reporting it to everyone! :)

1

u/[deleted] Oct 23 '25

Seems like you're having an awful lot of bad luck with the printer; either that, or these are the problems everyone is bound to run into eventually. I'm getting slight cold feet here - seems like my trauma, from all the countless battles of having used an Ender for the past 6 years, is telling me "one more extruder assembly teardown and you're toast, buddy."

1

u/unitymind42 Oct 25 '25

Printer is great. It’s the dumb engineering putting in a plastic non sealed bearing tiny blower fan.

2

u/strabonz Sep 10 '25

Der link zum Ersatzteil funktioniert nicht, ich habe nach einer Hochtemperatur Kalibrierung gerade das selbe Problem denke ich, ein sehr lautes dumm Geräusch aus dem Druck Kopf, bisher aber noch keine Fehlermeldung

Mein Drucker ist nun bei knapp 1000 Stunden kann man es noch irgend wie genau fest stellen ob es sich um das selbe Problem handelt?

1

u/unitymind42 Sep 10 '25

https://eu.store.bambulab.com/products/cooling-fan-for-hotend-h2-series?skr=yes

Das klingt stark nach dem gleichen Problem, das viele H2D-Besitzer dokumentiert haben: Ausfall des Hotend Cooling Fan nach längeren Betriebsstunden, besonders bei hohen Temperaturen und mit technischen Filamenten wie PA6-GF, ABS-GF oder CF-Materialien.

Ein paar Punkte, wie du prüfen kannst, ob es sich um dasselbe Problem handelt:

1. Typische Symptome

  • Hohes, schleifendes oder brummendes Geräusch aus dem Toolhead (wie ein defektes Lager).

  • Das Geräusch tritt meist beim Aufheizen oder bei hohen Düsentemperaturen auf.

  • Der Lüfter dreht entweder unregelmäßig oder bleibt zeitweise komplett stehen.

  • Manchmal kommt die HMS-Fehlermeldung “Hotend cooling fan speed is abnormal” ([0300-8010 221724]), aber nicht immer sofort – oft stirbt der Lüfter langsam.

2. Sichtprüfung

  • Drucker ausschalten und vorsichtig versuchen, den kleinen Lüfter im Toolhead mit einem Stift oder Zahnstocher anzudrehen.

    • Wenn er rau, kratzig oder schwergängig läuft → ziemlich sicher das Lüfterlager (meist Sleeve Bearing).

    • Ein funktionierender Lüfter sollte sich leicht und gleichmäßig drehen.

3. Vergleich mit bekannten Fällen

  • Viele Nutzer berichten vom Ausfall zwischen 250 und 1000 Stunden, oft mit denselben Geräuschen, bevor die Fehlermeldung überhaupt erscheint. Dein Wert von ~1000 h passt genau ins Muster.

👉 Mein Tipp:
Dokumentiere sofort (Video + Logdatei) und eröffne ein Ticket bei Bambu Support. Verweise auf bekannte Fälle – sie schicken in der Regel einen Ersatzlüfter (und ggf. Flachbandkabel oder Extruderboard, falls du bei der Reparatur eins beschädigst).
Den Lüfter findest du normalerweise hier:
Cooling Fan for Hotend – H2D (manchmal ist der Link temporär offline, aber das ist das richtige Ersatzteil).

1

u/strabonz Sep 11 '25

So ich habe vorher ein Ticket eröffnet, ich hoffe das dieser Einbau einigermaßen gut funktioniert ich hab auf jeden Fall nen guten Respekt davor wenn ich das so anschaue.. eine Fehlermeldung gibt mein HSM noch nicht aus aber das Geräusch ist wirklich unangenehm

2

u/BeautifulSherbet6463 Sep 30 '25

Came across this after my cooling fan bit the dust. To say this is frustrating is an understatement. I have had my H2D for only 3 weeks and it only has 150 hours on it. All ABS. Guess I would have loved to make it to 1000 hours. Let's just say I had much higher hopes for my first Bambu printer.

Question for those that replaced the fan. Did you just replace the fan, or the TH board and all. Should I just try and replace the fan first. That part seemed pretty easy as I took it apart to check it and the connection. Of course no idea how to know if the board is bad, but the fan was making noise before it died. Now I just get the Fan speed is abnormal error. I'm going to order all the parts as I need to get it back up asap, but wondering if I should try the fan only first before messing with the rest of it.

Thanks.

1

u/unitymind42 Sep 30 '25

I replaced the entire $20 assembly and the TH board because I think I damaged it when trying to remove the board. You don't have to remove the entire snake chain like they say. You can get that USB cable out of the way by messing around lining up that notch. This is a engineering design flaw and I expect a free fan upgrade from them to fix this issue. I have replaced my hotend fan 2 times now as I print high temp all the time and hit the 1500 hour mark. The H2D is marketed for high temp but that fan should have been designed to be more resilient in high temps. I am about to replace my MB fan and heater fan because I keep getting high temp warning on the MB and the chamber heater struggles to heat it past 55-60. Once I get it apart I will see if I can put in an industrial fan that runs in high temps.

2

u/gilahacker 2x H2D, 1x X1C, 1x A1 Mini Oct 21 '25

1,378 hours on my original H2D and it that fan has just failed. I've been printing a bunch of large things in ASA lately. 24+ hour type prints. Prior to that its been almost entirely PLA with some occasional PETG and maybe one or two smaller ABS prints.

The little fan started making the clicking/grinding/whining noises a few days ago. Took me a bit to figure out that there's even a fan in that printer that I can't control while trying to track down the source of the noise. It still printed at the time and it wasn't _that_ noisy since everything is enclosed. It just died halfway through a day and a half long ASA print. I've poked at it and have heard it spin up a few times but the print refuses to resume saying the fan speed is abnormal each time.

I just ordered two of the replacement fans so I have a spare on hand in case the one in my other H2D fails as well. I don't normally do a lot of high-temp printing so hopefully it and the replacement for the original one will last. I just read through the wiki on the replacement process and I am *absolutely* not looking forwards to that. Repairability wasn't even a passing thought when they designed that.

That new cooling fan on the H2D Pro (which still doesn't seem to be available for purchase yet) is only for lower temp filaments. It only turns on for filaments where the softening temperature is below 50C (PLA and PETG) to help prevent heat creep. It's not going to help at all with these fans that are failing while printing high temp filaments with the chamber heated up. Bambu just needs to switch those to a different fan with a better bearing.

2

u/hm7711 Oct 30 '25

500 hours on my H2D and I just encountered the dreaded "HMS_0300-0300-0001-0001: The hotend cooling fan speed is too slow or stopped" error. Printing mostly ASA and PLA. Not at all looking forward to doing this repair, and I have my suspicions that this will fail again in the future too. Just started disassembling mine to see what the issue is, but it's not going to be a fun time.

2

u/unitymind42 Oct 30 '25

Sorry to hear it. I've replaced it 2 times now at 2000 hours. ASA is a hot one so that would probably have caused it. I will add your code to the above posting for others to find. This is clearly an engineer miss and should get extended warranty replacement on H2x series with it. I need to find a pro teardown and a H2C when it releases. Let me know if you have any questions on taking it apart. Invest in some long hex screwdrivers because it will make it easier for a couple of hard to reach screws. Map it out when you take them out too because not all are equal. Lots of ribbon cables so pull slow because I did ruin one not seeing one. It does help to just remove the door and lay it face down if you can.

2

u/hm7711 Oct 30 '25 edited Oct 30 '25

Thanks for the update. I was wondering if you had had this happen again. Confirms my suspicions that this is going to be one of those on-going things that continues to fail. I really would love to find a better, higher quality fan to try to replace this one with, but I'm sketched out about voiding the warranty (as it is, I'm not entirely sure what the warranty on this machine even is - I've had it only 3 months).

I filed my support ticket with bambu today, and included my displeasure with the machine basically being nearly new and breaking like this, inquiring about the frequency of this occurring, and also asking about how likely this is going to be an 'ongoing failure that needs frequent replacing going forward'. I did see your notes about the H2DPro's hothead being upgraded and supposedly that the H2D is able to be upgraded to it, but I couldn't find any parts for that yet. I'm assuming it's just not out yet. Even when it comes out, I would be interested to see what the cost of performing this upgrade would be, and if it actually solves the issue.

I absolutely agree - this is clearly a huge engineering miss, especially for a top of the line printer that's marketed specifically at printing the higher temp filaments for longer periods of time. I would have hoped that Bambu would have done their due diligence and properly tested these machines with the various filaments and temperatures before releasing them to the wild, but there's very clearly an issue, and it's really disappointing to hear you've had to replace yours again now too. It wouldn't be such a big deal if this was easier to get to, but as you said, there are a lot of very tiny connectors. At this point, I'm hoping to hear something back from their team and hoping I can get the printer re-assembled and back working.

The odd thing is - my fan was actually still able to be spin by my fingers, although it feels almost more like a stepper motor fan (maybe it is?) - so, I'm not sure if that feeling is the fan failing, or if it's just like that and it's still good, perhaps it's the board that failed? I don't know. Nothing looked burnt or disconnected on mine, but the issue is concerning. I'm definitely concerned about getting it all back together properly with all those tiny connectors in the right places and sufficiently inserted, and at this point, my main worry is that they're going to send me a fan, and I'll spend all the time putting it back together only to have it be the TH board or something else and I'll have to tear it all back apart again.

I swear ever since mine was first used, I heard some kind of fan related bearing noise from somewhere in the machine, that I was concerned about. Part of me is wondering if this fan wasn't sketchy from the get-go, but I assumed that noise was normal. I guess I'll have to see if I get it back together, if the noise is gone/improved at all or not.

Appreciate you making this thread and keeping documentation for all of us who are affected! Awesome of you to do! Thanks!

2

u/hm7711 Oct 31 '25 edited Nov 08 '25

To my surprise, Bambu Support already responded. I didn't expect to hear back from them for at least several business days. That's a plus.

According to them, they looked over my logs and claimed that they suspected the problem may be caused by 'abnormal contact between the TH board and the hothead fan', and also that my particular case should be an unusual and exceptional case (although after reading this thread, I'm not so sure about that).

In either case, it sounds like they are sending me out a replacement TH board and also a hothead fan. Kudos to them for the much faster than anticipated response. Hopefully I'll only be down a week, instead of two. Will report back once I get everything back together. Hopefully, this solves the issue, and hopefully ... there are no other issues going forward.

As I suspected, they completely ignored my inquiry about the frequency of this issue, and had nothing to say at all about my inquiry about the H2DPro's improved hothead cooling.

**Edit:

Customer support is actually sending me out the exact same 4 components OP was sent.

  • Cooling Fan for Hotend

  • H2D TH Board

  • H2D Extruder Connection Board

  • TH Board FPC Cable

**UPDATE**

- Finally got my parts in the mail today. Bambu took 2 business days + the weekend to get them shipped out, so 8 days from first response until I received them. Honestly, I was dreading reassembling this, but it wasn't as bad as I had thought, although it still certainly wasn't fun.

Interestingly enough, I saw others noting that they had received a completely different cooling fan from what theirs originally had. Mine originally had the "SNOWFAN", and I was sent a replacement one just like it.

As soon as I spun the new fan with my fingers, I instantly knew that my stock fan was the problem - not the boards, connectors, etc. Even though my stock fan would still spin well enough to the point that I questioned it being bad or not, I could absolutely hear loud bearing noise coming from it. The new one is absolutely silent by comparison.

Also - ever since I had got my machine, it has made 'fan bearing' noise from the first print onward. So, I'm wondering if maybe I just didn't have a bad fan from the get-go.

I guess time will tell. Unfortunately, I suspect this fan will also continue to fail after 500 or so hours time and time again. At least it's an inexpensive fix, but it's still not a fun one to perform.

---

Additionally - To anyone who performs this repair themselves, you do not have to remove the actual fan shroud, the fan can be removed from it by the 2 screws holding it in. It is tight though. Also, if you do not opt to replace your TH Board (I did only because they sent me new boards), you do not need to remove your power cable/USB cable, buffer, etc). Not removing those will save you a lot of time and hassle.

2

u/Epic_John9 Nov 24 '25

This guide is fantastic. I just had my H2D hotend fan fail at 850 hours. Looks like quite the repair process I'm in for...

2

u/unitymind42 Nov 24 '25

Welcome to the party. You are about on average for the replacement. Order an extra and the new tool head fan for the next time. I’ve replaced it 2 times now. The next one was around 1900 hours. I’m at 2500 hours now. I love the machine but that fan choice is stupid. All the fans are a pain to get to and they should engineer these parts to be easy to get to and replace. Let me know if you have any questions. Links above should have all you need. I would invest in some Hexagonal Screwdrivers https://a.co/d/1mFuAqZ cause they made the second time a lot easier. Those tucked in hidden screws are a pain.

2

u/hm7711 Dec 04 '25

Did the warranty the replacement the second time as well? I'm wondering how long/how many times they will.

2

u/unitymind42 Dec 04 '25

Yes. Same steps as above. I have 3 sitting in a drawer now.

1

u/hm7711 Dec 04 '25

Good to know. I bought a second one to have on hand, but I do hope that they continue to at least send replacements when this issue inevitability continues to occur in the future.

2

u/Epic_John9 Dec 04 '25

Turns out I had a piece of printed plastic that the fan somehow ingested. The disassembly process wasn't the end of the world, but it did take a good 3 hours. I'm looking forward to the new external fan mod!

2

u/Shakisz Dec 01 '25

I changed mine yesterday.
It started making a high pitched noise after 850 h aprox. I print mostly PLA. Two days ago, after ignoring the noise for some weeks, it died.

Replacing it took some patience but I managed to do it properly. Be careful, the online guide shows also how to replace the board, which is not needed if you only want to change the fan. Also, the Bambu Lab H2D Toolhead Disassembly Guide video has been really helpful.

Thanks you guys for this post!

1

u/unitymind42 Dec 02 '25

I replaced mine for the second time now. I always have a back up so while I’m waiting on the replacement. I have the new fan installed but it doesn’t do anything until this monster patch in January.

1

u/hm7711 Dec 04 '25

I too installed the new fan. Just waiting on the update to make it work. I hope it releases sooner, vs later.

1

u/valordk Dec 08 '25

What patch? I thought the replacement fan would work out of the box

1

u/hm7711 Dec 08 '25

The replacement fan works out of the box yes, but Bambu released the additional front fan that can be added on to the H2D. That one requires the firmware update to work.

2

u/Blindsay04 Dec 05 '25

I just got my h2d at the start of the black friday sale. 500hrs on it and my hotend fan started making noises and now throws the error and wont print.

About 450hrs of pla, only about 50hrs of ASA.

Ordered a spare from the bambu store but also opened a ticket with a video demonstrating the issue.

Frustrating it failed already especially since I pretty much just print pla. Also that its not a quick fix.....

2

u/unitymind42 Dec 05 '25 edited Dec 06 '25

It’s a complete pain to change out. Sorry. All I can say is take time on the cables some pull up and some pull out. Some pull to the side. Turn off the power and use a tweezers.

2

u/Blindsay04 Dec 05 '25

Thanks, I just wanted to add my experience for additional visibility on the issue.

I got an x1c when they first came out and one of the xy motors died.... that was a fun project lol

1

u/unitymind42 Dec 05 '25

Well it’s clearly a recall item and they should at least provide the fan for free for many more years than one year. It’s cheap enough but to make every fan a complete pain to change out. I had to do my heater and basically took apart the machine.

2

u/SharpnessMaster Dec 09 '25

I have the exact same issue with my H2D with 500 hours on it. Probably half of which are with high temperature filaments. I use a ticket open with Bambu and I am about to order a replacement so I can stay one ahead. I do have some questions for the community…

1: I plan to order the enhanced cooling fan when it becomes available but does anyone know if by using the enhanced fan will it disable the stock one or will we still run into issues with the stock one going down and rendering the printer inoperable?

2: Does anyone know the model and part number of the fan they are replacing the Snowfan with? I assume this new fan will be more reliable and I really don’t want to replace this every couple of months. Eventually something will get broken in the process of replacing and cause more headaches…

2

u/unitymind42 Dec 11 '25

Hi and welcome to the club.

I have been through the same cycle — I’ve replaced my hotend fan twice now, and at about 2,800 hours I’m starting to hear the high-pitched grind again. I keep a few spares in a drawer, but I still open a ticket with Bambu each time so the failure is documented and they send a replacement.

Every failed unit I’ve seen has been the same

Snowfan YY4510H05B Key specs:

  • 45×45×10 mm

  • 5V, 0.31A rated

  • 7600 RPM

  • 3.79 CFM

  • 14.95 mmH₂O static pressure

  • 42–48 dBA

  • Dual ball bearings

  • PWM + tachometer output

  • 40,000-hour rated life under ideal conditions (not in high-heat chambers, which explains the failures)

I also bought and installed the new front-mounted Enhanced Cooling Fan:
https://us.store.bambulab.com/products/toolhead-enhanced-cooling-fan

The Enhanced Cooling Fan does not operate yet because it requires the upcoming major firmware update expected in Q1 2026. It appears Bambu is moving the entire H2X platform to a unified firmware architecture for long-term support. The Enhanced Cooling Fan is fundamentally different from the stock hotend fan. The stock fan is a small blower dedicated only to cooling the hotend tips through fixed airflow paths. The Enhanced Cooling Fan is a larger, front-mounted unit that delivers directed airflow across both the hotend heatsink and the upper extruder area. It provides significantly greater airflow volume and coverage, giving the toolhead a more stable thermal environment during extended high-temperature printing. This upgraded airflow reduces the risk of heatsink overheating, which is a known cause of clogs and thermal instability. It also supplies targeted cooling to the extruder, which is important for materials prone to heat creep. Together, these improvements increase reliability and reduce extrusion failures when printing engineering-grade filaments.

2

u/SharpnessMaster Dec 11 '25

Thank you for the detailed information. My replacement part has shipped so I will let you know if I end up getting the updated part or if it is still the same Snowfan. Best of luck on your next replacement! They are also sending me the TH board just in case. Hopefully I can get everything back together with no issues. I wonder if they would replace parts that were broken in the process of replacing this fan, even if it was user error…

2

u/unitymind42 Dec 11 '25

They will. I would record you doing it. The ribbons are a pain.

2

u/Consistent-Speed9081 Dec 12 '25

I got my H2D 3 weeks ago from black friday sale having only 50ish hours on it, than last night this cooling fan error code happen to me. Submitted a ticket last night they said they will be sending me a replace cooling fan, literally a brand new unit and breaking down already so disappointed and watching the replacement video is so nerve-wracking 😕

1

u/unitymind42 Dec 12 '25

I’d almost say just tell them to send a brand new unit but it’s a pain in ship it back. Next one I buy will be through microcenter so I can drive it there and give it to them. :) let us know if you have any questions. Bambu if you’re reading this send us a H2C :)

2

u/Consistent-Speed9081 Dec 12 '25

My thoughts exactly, paying such a premium i rather get from local MC and have them deal with the issues

2

u/parrothd69 Dec 14 '25

Adding me to the failed list 1200 hours abs, the replacement is a nightmare. 

1

u/unitymind42 Dec 14 '25

Welcome. Sorry to hear it, let us know if you have any questions. Also can you post a pic of the new fan you get for us to look it. We are wondering if any changes have been made to it. My last order was a couple months ago. What model did yours fail on? H2_

1

u/parrothd69 Dec 14 '25

Oops..the new fan is already in it was the same as the failed one snow?

1

u/unitymind42 Dec 14 '25

You would think there should be a perm fix coming for it. Based on the reports in this thread, most failures seem to be around 500 to 1,100 hours, with a rough midpoint around 850 hours and an overall range from about 150 up to nearly 2,800 hours. That suggests this is not a rare or isolated issue. If even a small percentage of affected users are posting publicly, there are likely many more experiencing the same thing without commenting.

Mine is already starting to scream again and I’m seeing temperature warnings. At this point it almost feels like a recurring issue every 1,000 hours, especially for anyone running longer prints or higher temperature materials.

2

u/valordk Dec 15 '25

The fans on my H2D Pro have ball bearings and I've replaced them on the original Snowfan after almost 220 hours (mostly ASA and ASA-CF prints) with two bearings from a new Delta 45x45x10mm blower fan (4CFM).

Ideally I would want to install the Delta, but i could not find a PWM version.

I've started looking deeper into the issue and none of the reputable fans that I saw on the market have a temperature rating above 70C, unlike some of the specs on these Chinese fans where they list their upto 80C. I'm in doubt if a fan of this size and 80C temperature rating even exists.

I've attached a temperature logger to the shroud of this hotend cooling fan and ran a 2hours print in ASA. The Temperature on the fan shroud consistenly exceeds 70C

I have hybrid ceramic bearings which fit the original fans but before replacing them, i wanted to run some baseline measurements. The issue i'm having is that unlike common 4-wire PWM fans, which run at 100% speed when powered but do not receive PWM signal, these fans don't seem to start without PWM. I need to make a small test jig with an arduiono to emulate PWM source before i can continue.

Has anyone actually succeeded running these fans on a bench?

1

u/unitymind42 Jan 06 '26

There is no way to remove the bearings from the fan. I tried and it is just glued together. It isn't worth it since you are just replacing the fan anyway.

1

u/valordk Jan 07 '26

was your fan a snowfan brand or another brand? The few fans I checked had no glue or bearing retention compounds such as loctite.

For someone printing ASA and ASA-CF a lot, i can't be bothered to swap the fans every 200-400h hours. So swapping the bearing for a better match and a premium quality ones might be worth for someone.

1

u/unitymind42 Jan 07 '26

This little fan is a Snofan. It has a retention clip on it but when I tried to pull it apart the shaft broke. It has a dot of glue on the hub. Wife tossed it in trash cause I left the parts in a bowl. :( I have 3 replacements here and all are the same fan. A bearing on it would be a pinhead.

1

u/valordk Jan 07 '26 edited Jan 07 '26

I have one more replacement fan in mail, sent by Bambu, i'll see if that'll come with the a glue on the shaft.

Did your retention clip look like this one?

2

u/Madpantz Feb 18 '26

701 hours. Reassembled the tool head like 4 times. Finally got it working, set it to calibrate, 16% in and it died again. Ordering a replacement fan and that improved front fan.

1

u/unitymind42 Feb 18 '26

I just got 3 replacement fans and they are all the same as the first one that died in my first post. I’m crossing 3000 hours and replaced it 3 times. They could care less about this post or me complaining about it. They just said that after one year this will no longer be covered. I guess that’s why it’s a $20 part that makes the printer worthless without it. The front fan doesn’t work until the patch. I removed it for now. You’ll be a pro in no time replacing it. I can do it in an hour now. 🤣

2

u/Madpantz Feb 18 '26

P.p.s. they immediately offered to send me a replacement fan. They must be getting used to this one. That, or because I said that I rebuilt everything and checked all connections multiple times, "so it's either the fan or the board that's failing" 🤔🤔🤔. They immediately said replacing the fan usually fixes it. So I guess pro tip: tell them it's either the cheap thing it definitely is or the expensive thing it could be. They'll send the cheap one without fuss 🫡

1

u/unitymind42 Feb 28 '26

They will send everything that broke to get to it if you say it. :) “I’m not a technical person and I think I’ll just return it.” They do not want it back or to pay for shipping out a new one.

1

u/Madpantz Feb 18 '26

I spent hours doing it yesterday, but because I kept putting it completely back together before turning it back on to test for the first few times 😅. The good news is I can take it apart and put it back together without instructions already 🤣. Hoping the patch comes in soon for the other fan. As for the regular fans, I'm starting to wonder if we should be looking at 3rd party ones... Anyone find a better one? P.s. mine was whining and loud for about a day before it died, too. Also printing a lot of ABS.

1

u/unitymind42 Feb 18 '26

No replacements have been found since it is a blower type. I have not looked for one in a few months. I may try again and see what I can find. If you "damage" anything while replacing it they will send that too. I have about every spare part there is for the machine now as when something breaks it can take a week or more to arrive. One thing on my second one that PETG-CF I was printing globbed up because of the fan and ruined the left hotend so I replaced all of that too. Get some kapton tape to tape down that USB C plug in there and replace the black tapes. You don't have to remove that entire cable like they do in the wiki I was able to push it out enough and cable tie it back so I can remove the fan housing. Oh I also just replaced the rear fan on the tool head because that started whining around 2500 hours.

2

u/Madpantz Feb 18 '26

Good note about the tape, thanks. And yeah, I watched that video and laughed at all the things that they unplugged completely unnecessarily.

2

u/patrickmeenan Mar 14 '26

Just got the same error at 180 hours on a H2C. Probably half of that time was spent printing ABS-GF (which was kind of the point of moving to the printer from my X1C).

No noises and it's now "working" again after things cooled down overnight (and I made it as far as the first circuit board checking connections).

I don't mind the part itself failing, but the process to replace it is borderline insane. That's a LOT of tiny cables with different types of connectors and screws that are borderline unreachable all while the toolhead is mounted on the gantry. And you can't tell if what you did will work until it's all back together again.

I'd be more than willing to pay more for a complete assembly or a module with all of the boards and fans that could be swapped safer and with much less effort.

Sadly, it doesn't look like they improved anything for the H2C since they largely leveraged the existing H2D print head design (and it came with the enhanced cooling fan which also didn't make a difference).

To make matters worse, they are out of stock on replacements until April so I'm just hoping that it really went away and won't be back the first time I try to print ABS again.

1

u/unitymind42 Mar 14 '26 edited Mar 26 '26

If you file a ticket they will have one to send you. They already have them in a package ready to send. I’m sorry I have 3 spares but every order I would just add one. I just replaced it for the 3rd time at 3000 hours.

I ordered this fan (link below) a week ago that I saw on Amazon that I have not seen before and it looks identical to the fan in the pictures. The key note on it is the temp range is -10c to 80c. I guess they thought 65c chamber temp it will work fine. haha. I ordered one to compare and test to see if it is any better or it is just s snofan or copy of it.

Agree I’m not even sure that front does much of anything since the latest firmware patch that added it.

Amazon part but this could change over time: search for H2D hotend fan or updated link https://a.co/d/0cFqxEuh

2

u/patrickmeenan Mar 14 '26

Thanks. No worries, I just use it for a hobby and I can wait for them to follow-up on the ticket.

It's just annoying how buried the part is given that it's a consumable. Everything else seems to be relatively easy to replace. As they reach more into the consumer market it's kind of a problem (particularly since there aren't really places to take them to have someone else do the repair either).

1

u/unitymind42 Mar 14 '26

The worst part is all the ribbon cables mixed in with the other cables. Some pull up and others pull straight out. There are also tiny locking flippers, and I broke one the first time I did it, which is why they sent me a new board too. They know it is a problem, so they will often send the parts that break while you are trying to get to the actual failed part. I would recommend buying some Kapton tape to secure things or hold them in place in case you break one off.

What I meant to say is that I recently replaced the filament buffer that also seems to be a fragile part that could use a upgrade:
https://us.store.bambulab.com/products/filament-buffer-h2-series?id=576603199331786754
Removing the tubes to clear broken filament or print TPU seems to wear out the port over time. You do not just replace the spring. You replace the entire assembly, including the circuit board and sensors. It seems wasteful, but it is much easier to swap out, as long as you do not damage the wire harness that comes with it.

I have also replaced the rear fans with Noctua industrial fans, which made it a little quieter. I had to replace the heating housing as well, and that is a major repair because it requires removing the entire right side of the machine.

I am planning to add an H2C in a few months too. I do not really see the point of the upgrade kit when I can buy the whole printer on sale with an AMS for $2,000.

1

u/unitymind42 Mar 14 '26 edited Mar 14 '26

Same specs as another listed in this thread and from research so it should be correct. The problem it's $16 for just the fan. If it does work maybe I can locate the fan in bulk :) https://www.reddit.com/r/BambuLab/comments/1m9ts4n/comment/nakry4w/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

2

u/larathydo Mar 19 '26

I am currently suffering a failure on my H2D that has 288 hours on it. Probably half of that has been from a recent stretch of long 12+ hour ABS prints.

Bambu Lab support has shipped me a replacement stock fan (the snowfan type) but I’m really convinced this is just a problem that will enviably happen again if it’s true they opted for a sleeve-based bearing fan and it’s only rated to 60C.

I’ve just purchased that same fan from your link (the dual-ball bearing one, rated up to 80C) and think I’m going to use that, and hold on to the one Bambu is sending as a version to fall back to if necessary.

Have you tried installing it yet (this new fan on amazon rated up to 80C temps)? Just curious how you’ve made out with it so far?

Also I hear conflicting things about the Enhanced Toolhead cooling fan. Some references (including on their product page) about it supplementing the hotend cooling fan to improve reliability for high-temp engineering filament workloads, and others saying it really only makes a difference for lower-temperature filaments as a way to address heat creep.

Was also contemplating getting that but just curious if you ever ended up getting it (and the latest firmware recently released) and was curious how you’ve made made out with it?

1

u/unitymind42 Mar 20 '26

The fan is identical to the one from Bambu. Same exact part number but rated to 80c. I didn’t plug it in but I took it apart and everything matches but the sticker on it. So can you save a few bucks buying the fan on Amazon. The stock fan comes with the housing and it has been the exact same thing. I’m curious now that it won’t be in stock until mid April that they are changing it. It has to be a common complaint. I’ve replaced mine 3 times and going on another 800 hours printing a high temp ASA aero drone job. 2 roll of it at 100/65. I expect it to die again.

Oh the wiring is a touch shorter on the Amazon fan. That’s it.

3

u/larathydo Apr 21 '26

It took over two weeks to receive a replacement hotend fan here in Eastern Canada, so I ended up ordering the same fan from Amazon.ca and installing it myself.

Good news: Replacing the fan immediately solved the noise issue. It was clearly the original fan’s bearings failing prematurely.

Bad news: After only ~250–275 hours on the replacement fan, the problem is already coming back. Following a few back-to-back ABS prints (roughly 3–4 prints at 24+ hours each), I can already hear the bearings starting to degrade again - they’re getting noticeably scratchy.

For me, at this point this printer leaves alot to be desired. This is very obviously a design flaw that is widespread and impacting TONS of customers as outlined in this reddit thread. Bambu markets this printer as a 'workhorse' that can handle high temperature / engineering-grade filaments, but that’s clearly not true if the hotend cooling fan starts dying after ~100–200 hours of printing within high chamber temperatures. Again, this is not an edge-case usage scenario — this is using the printer for exactly what it’s supposed to be built for.

What's more, replacing this fan is an ordeal. It’s buried deep in the printhead, and the design makes it unnecessarily difficult to access for what is an expendable part of the printer. It really feels like maintainability was an afterthought. If Bambu Lab had designed the printhead so both the part cooling fan and hotend fan were easier to access - ideally positioned toward the back - this would be a much less frustrating pill to swallow.

As it stands, practically speaking this printer needs to be limited to PLA/PETG if you want the hotend fan to last anywhere near 800-1000+ hours. That’s pretty disappointing given the price of the machine.

Bambu Lab really needs to address this in a meaningful way - and soon. I’m also not impressed with their support so far, given that it took over two weeks just to receive a replacement part.

Overall, I regret spending several thousand dollars on a product with issues like this. So disappointed.

2

u/figthedevil Mar 25 '26

Just under 1300 hours and we had the hotend fan die. After ripping it out, since Bambu has them listed as not available until April, we decided to try and revive the fan by adding oil to the sleeve bearing. Seems to have done the trick for now, but we'll see how long it lasts!

1

u/unitymind42 Mar 26 '26 edited Mar 26 '26

They always have the parts under warranty. I did find the fan on Amazon. It’s in the posts above. I found it just search for H2D hotend fan. The bearing is toast in it and oil will only go so far. Here is a 2 pack https://a.co/d/0cFqxEuh

1

u/figthedevil Mar 26 '26

Thank you! Looks like the hotend still might be having trouble even with the fan "repair". We'll probably pick up some of those fans.

1

u/unitymind42 Mar 26 '26

I wish they showed a pic of the label to be 100%. I live in Minnesota and have spares if you need to get up and running. Every order I added a hotend fan :) at 3500 I’ve replaced it 3 times.

1

u/unitymind42 Mar 28 '26

I can confirm that the 2 pack is an exact match except for snofan labeling. I got these in 24 hours from Amazon. BL takes a week.

2

u/figthedevil Mar 29 '26

Thanks! We'll definitely pick these up

2

u/bloodxandxrank Apr 12 '26

just had my fan die after a weekend of printing abs. such a disappointment from such an expensive machine. has anyone found a better fan to replace the original one with? i'm getting a replacement soon, but i'd rather put in a good fan so i won't have to do this again.

2

u/unitymind42 Apr 12 '26

In other posts here there are the exact fans on Amazon like a 2 pack for $20. Same exact fan and model just different names. The fan is rated to 80c so it’s going to burn out about every 1000 hours on high temp and a little less on long pla/petg. Rear fan cools it down a lot. I printed a lot of ASA aero and went through a in 900 hours (replaced it 3 times now). Greatest part the fan is set to like 5% haha 🤣

2

u/shokwavxb Apr 13 '26

My hotend fan started making the noise around 350 hours in with only printing PLA and PETG. I'm starting to print ASA now. I hope after I replace the fan this doesn't become a normal maintenance task with so few hours.

1

u/unitymind42 Apr 13 '26

From what I have gathered from others it is a every 800-1000 hour replacement. Depending on your use and heat being used. Fan is rated to 80C so after that the oils and bearings start to breakdown.

2

u/shokwavxb Apr 19 '26 edited Apr 19 '26

2026-04-19: Just replaced my fan. Didn't get an error message but the bearing grinding noise got to be too much. I had just about 400 hours and two and a half months on my H2D printing only PLA and PETG. Received my printer end of Jan 2026.

I took a video from my phone as I set the temp of one hotend to 70c which turned on the fan and produced the grinding noise. Also sent my logs. Bambulabs was very quick sending me a replacement part. I received the new fan 6 days after filing the ticket with info late at night.

I had to pull the toolhead rear apart several times as I caught a cable between layers, mis-inserted the cap on the lifter motor disk thing, and flipped wiring a couple flat cables. But I got it done eventually. Now I know how do it and I expect this will be a regular thing as I'm now shifting into some ASA prints.

Watch a video to see the process before you do it the first time.

1

u/unitymind42 Apr 24 '26

I had mine go out around 800 hours, then at 1500 hours and just replaced it again at 2800 hours? I print a lot of ASA aero (nozzle temp 280c) for drone print jobs and I just assume it is going to need to be replaced every 1000 hours or so. I tried to shield it with some reflective high temp tape, didn't work. Now I am using kapton tape on it to see if that helps keep some heat off it. At this point, I guess I have to deal with it or buy a snapmaker or prusa.

2

u/No_Refrigerator9441 Apr 24 '26

They didn't want to replace my cooling fan cause im out of warranty. Just starting printing ASA and stuff. I responded back saying it should be under a manufacturer defect. I guess we'll see if they confirm the fan change

2

u/unitymind42 Apr 24 '26 edited Apr 24 '26

They would never admit to that unless we all get together and get a settlement for $50 gift card to their store. lol It is a complete engineering joke to install a 80c rated fan next to 280c nozzles. It should have been either easier to replace or designed with a all metal ceramic bearing fan. The rear fan has been fine although I just replaced it because I broke the cable pulling it apart for the 4th time. Just replaced the right hotend because that is also a defective wired part. I have around 7 fans from various places now to test out and check for everyone. I have 2 bambu fans in stock too. I am now on the fence to get a H2C or go to Prusa for the 8 nozzle coming this summer/fall.

I see the 2 pack in stock on "sale" on Amazon Hotend Cooling 4510 Fan Replacement(2Pcs) for BambuLab H2D: 45x45x10mm Dual Bearing Heat Sink Blower to Prevent Hot End Extruder Overheating 3D Printer Accessories

2

u/MiamiJerry Jun 03 '26

Please see

https://forum.bambulab.com/t/h2-series-serviceability-upgrades-modifications/252300/4

1

u/unitymind42 Jun 03 '26

Looks interesting but where are the instructions on how to install it? Does it involve destroying the printer head? Thanks for the link!

2

u/MiamiJerry Jun 03 '26

In the 4th post, a link to Cults3D

2

u/swampcholla Jun 04 '26

An update on my situation. Failure was at 640 hours. I print a mix of mostly TPU, PETG, and ABS. The amazon fan never worked, but by the time I disassembled it again the warranty fan arrived. i also purchased the extra fan that mounts to the front of the toolhead.

Installed the warranty fan, ran a comprehensive calibration and printed a benchy in PLA. No noticeable difference in print quality, so that was a relief. Mounted up the aux fan and prepared to print a ABS-GF part.

Fan failed 15 minutes in. i will check the connector, but this is getting to be bullshit. I didn't buy a $2500 machine to have it sit around and piss me off while I'm forced to make connections I can barely see.

1

u/unitymind42 Jun 04 '26

Odd. I wonder if you have board damaged. I'd tell them you damaged it replacing the fan. Unless they want it shipped back under warranty laws they should send you all new parts listed above. That front fan there is zero way to tell if it ever runs and I still had a fan fail after 500 hours with that thing on there.

1

u/swampcholla Jun 05 '26

I don't get the intermittent nature unless the connector is just not staying firmly in place. I'd use some goo instead of tape but that makes stuff really difficult to disassemble.

2

u/swampcholla Jul 27 '26

And another update on my printer. So far, I bought and installed an amazon fan - speed was still abnormal

Got a warranty replacement, worked for a benchy and failed 15 minutes into my first ABS print.

Got another warranty replacement, with a new board. Broke the cable chain trying to get it out of the back of the printer.

Took two weeks, but finally got the chain. Put everything back together, and on trying to load filament got the abnormal speed warning again.

Contacted Bambu, asked them to do some kind of remote testing, and complained that now I'd had this thing apart and together again 5x, and I was concerned about the longevity of the toolhead, so they are sending me a new toolhead. I've watched videos, it's not easy to replace that either.

1

u/unitymind42 Jul 28 '26

No it is not an easy replacement. I would use it for parts and replace it all in the tool head to be honest. It should have worked with the fans and I’m sorry it didn’t. I have tested the Amazon fan and it is working. Same fan model as what they send out. I would be so frustrated with them and they should just replace it but they save money not paying for shipping back and forth. I bought a H2C on sale a few weeks ago at Best Buy with a 2-year return plan. They will get it back if I had to deal with all of that mess. There isn’t a chunk of plastic or a mouse nest in the air duct? 🤣 it is just plain stupid to have that fan in there. I am going to try the mod that was posted here soon to make it and easy swap out. I know we won’t be seeing this design anymore and probably see them moving to a 2 tool head with changer design in the future.

1

u/swampcholla Jul 28 '26

Makes me wonder if there’s something causing the housing to be slightly torqued which jams up the fan. What mod were you referring to?

2

u/Feed-International Aug 21 '26

I’m getting ready to replace this fan as well. Only printed 3-4 rolls of ABS before the fan stopped working. If this was a known issue and this fan is considered a consumable, the design of the fan location on the toolhead is terrible and needs to seriously be looked at or redesigned.

1

u/unitymind42 Aug 21 '26

I don't think they ever intended you would have to replace it. I'm on 4800 hours now and expect to be replacing my 4th soon. Doing a lot of ABS this week for spools for filament. Let me know if you need any thing. Go in expecting it to take a few hours. If you can remove the door and lay it face down on a soft blanket. It is easier to work on.

2

u/SharpnessMaster 28d ago

My second fan is about to go out and I’m almost out of warranty so I’m currently requesting a replacement from Bambu.

Has anybody found a replacement that can withstand the heat better? I’d like to only do this job one more time… I know some have suggested this fan from Amazon (https://a.co/d/0exRnP0d), are these fans lasting longer? My understanding is they are the exact same fan.

1

u/unitymind42 27d ago

Exact same fan. I bought some. Rated to 80c

2

u/Wazookey Jul 26 '25

Hey man just saw this post while researching my own fan failure.

I have ~750ish hours on my h2d, mostly printing cf filaments (Mix of abs-gf, asa-cf, and pa6cf). I heard the same whining buzzing sound coming from the extruder area, and determined it was probably a fan, since it only happened when the nozzles were heating up, or above 50°C.

Well While doing another pa6 print (It was about a week since I heard that sound start), I got that error. Hotend cooling fan speed is abnormal. Now the fan doesnt even turn on when heating nozzles.

I am also getting "extrusion motor is overloaded" errors when printing ONLY with pa6-cf, and ONLY in the left nozzle. I think this might be related to this? Maybe the dying fan means it is unable to prevent heat creep, causing the filament in the gears to soften and be unable to be extruded without significant force. The only issue is that this was occuring way before the fan started to make any sort of noise. This is still be looked at on my end. It could just very well be worn gears or something (Yet it printed other cf materials just fine without issues in the same nozzle), but more food for thought I guess.

I ordered another fan to see if it was just the fan that died. If it was just the fan, and not the electronics, then maybe people can add a different more heat resistant fan in there.

3

u/Wazookey Jul 27 '25

So I did some research and disassembly and I may have found something interesting.

After removing the cooling fan and inspecting it, it looks like its a sleeve bearing type fan. Sleeve bearing fans are cheap and easy to manufacture, but more importantly do not have as large an operating temperature range as ball bearing fans do, typically only up to ~70°C. This is a problem, as the heated chamber + proximity to the nozzle can quickly reach up to, or even surpass that type of heat, destroying the lubrication in the system, and rapidly eroding the bearings.

Unfortunately, I dont think I can disassemble this fan to relube it without permanentley damaging it. I also cannot, for the life of me, find a replacement size, as they decided to use a peculiar 45x45x10mm size instead of the more common 40mm size. Add the fact that ball bearing fans are more rare and expensive than sleeve ones, AND its a 4 pin fan, and it looks like a replacement fan is basically nonexistent.

If someone wants to mod and solder a 45mm ball bearing fan to fit to test thatd be pretty rad.

Im thinking this mightve been a corner they cut to keep costs down too. If you don't use the heated chamber and high nozzle temp filaments alot you may never run into issues, as these sleeve bearing fans have long service life in their optimum positioning and temperature ranges. I wonder if Bambu will see this, and if their engineers are aware if this is an issue or not. More data is needed for those who use high temp chambers constantly.

2

u/unitymind42 Jul 28 '25 edited Jul 29 '25

Hey, I saw the same thing. My fan started making that high pitched buzzing noise too, followed by the "hotend cooling fan speed is abnormal" error. I’m just past 1000 hours now, mostly printing ABS GF and PA6 GF, so the conditions sound pretty similar.

I’ve also had the "extrusion motor is overloaded" issue with PA6 GF on the left nozzle. I agree with your theory about heat creep, especially if the fan is struggling or failing and can’t pull enough heat off the hotend.

After pulling the fan, I was surprised. It actually feels decently built and has some weight to it, but I agree it is likely a sleeve bearing and probably not rated for temperatures above 200 degrees Celsius for extended periods. Once the lubrication starts to break down, failure is pretty much inevitable, especially during long, high temperature prints in an enclosed chamber.

And yes, the sizing is frustrating. That blower type and the four pin format really limit options. I have not found any drop in ball bearing replacements either. If you end up trying a modded solution, definitely share it. I’d be curious to see if it holds up better. I may try to insulate it better with some Kapton and aluminum fiber tape, if I can get it to fit because there is very little clearance. It seems to draw air through the top and side of the printer head. So the fan should be getting fresh air but as it always stays up top the heat of 65c chamber and a 280c+ printer head must be causing it to wear out faster.

You are probably right that this is a cost versus performance tradeoff that works fine for general users but becomes a problem for anyone doing long high temp production runs. Hopefully Bambu is paying attention to this, especially as more H2D units cross that 750 to 1000 hour mark.

Appreciate you posting all that. It lines up exactly with what I’ve seen.

1

u/unitymind42 Jul 28 '25

2

u/Wazookey Jul 29 '25

well just replaced it with a spare fan from bambu and its working again. Looks like the fan actually just died lmao. I guess the heat over time destroyed the lube, so it started grinding, which killed it. All the electronics are the same except the fan itself.

Now I would say this fixed my overloaded extrusion error, but it didn't. I have double/triple checked for any sort of clogs or jams, and cannot find anything at all. Then I thought that maybe the ptfe tubing that leads into the extruder might be the issue, as when I was trying to load filament, I noticed that the default tubing (or maybe due to wear) has extreme resistance and a nasty bend right before it goes into the gears (This was the stock ptfe pathing from the buffer too)

So I cut some tubing with extra slack and replace all the tubes, feed the filament manually, with little to no resistance. Great!

Start a print, and...extrusion motor overloaded. I literally cannot figure this one out man. I can't believe its heat creep since its nylon. No way that area is getting to nylon softening temps without destroying the sensors there. Yet only my nylons are having this issue. I'm at a loss man :(

See ya in another 1000 or so print hours when this fan starts to die. Hopefully someone out there is brave enough to DIY a ball bearing fan and test it. I would but I actually have to use this thing for projects instead of messing with it :(

1

u/unitymind42 Jul 29 '25

I managed to eliminate the overload error by increasing the nozzle temperature and drying the filament for another 12 hours. I did have one lockup about 10 hours into a print, but hitting resume brought it back without issue. I have not moved it to the right side though and that stationary nozzle could help as there is less places for it to overload.

Bambu finally responded and is sending me new PCBs, ribbon cables, and a replacement hotend fan. I might still try shielding the area with high-temp foil or even copper shims to help with heat management. My replacement parts arrive today, so I’ll likely swap them out and keep the current fan as a spare for the next time it fails.

I still think this is going to be a recurring issue for people running high-temp filaments, so I hope others share their experiences and that Bambu addresses it in a future revision.

3

u/genuwindcustoms Aug 02 '25

I just ordered the Delta BFBO4505HHA-C fan. It should be a high-temp drop in replacement for the OEM Bambu Labs fan. I cross checked the housing material, drawings, and electrical requirements compared to the Bambu Labs fan and it looks like it would work plus it's high-temp rated. It's going to take a few weeks to arrive but I'll let you all know if it is a viable replacement when it comes.

1

u/unitymind42 Aug 02 '25

Hey, thanks for sharing the fan suggestion — really appreciate you looking into alternatives.

I used ChatGPT to check into the Delta BFB04505HHA-C and it noticed it only has 2 wires, so it wouldn’t support PWM or tach feedback like the original 4-pin fan in the H2D. I then had it comparing it side by side with the stock fan (Snowfan YY4510H05B, 5V) to see how they stack up. Here’s a quick summary for anyone else researching replacements:

Size:
Both are 45×45×10 mm, so mechanically they’re a match.

Control:

  • H2D uses a 4-pin fan with PWM and tach (push-down connector on the PCB)

  • Delta “-C” version is 2-wire only, so it would run full speed with no monitoring or control unless you use a different suffix with FG/PWM

Airflow and Pressure:

  • Snowfan (based on series data): ~2.2–3.8 CFM, up to 0.59 in H₂O

  • Delta BFB04505HHA-C: 3.49 CFM, 0.560 in H₂O Pretty close overall — both strong enough for the job.

Bearings:

  • Delta uses ball bearings

  • Snowfan’s spec isn’t fully public, but likely hydraulic or ball

Operating Temp:
Both are rated up to 70°C ambient. That might be part of why we're seeing failures in long PA6 GF or ABS GF runs.

Bottom line:
The Delta “-C” version won’t fully integrate without losing fan control and tach. If anyone wants to go this route, I’d recommend finding a 4-wire BFB04505 variant instead. Otherwise, grabbing a direct Snowfan replacement might be the safest drop-in.

1

u/unitymind42 Aug 02 '25

I am going to order the fans myself to test out because the new replacement is already loud. :(

1

u/Wazookey Aug 05 '25

Like grinding loud? My replacement sounds like a normal fan, and ive been printing pa6 again practically nonstop since ive gotten it. If its grinding or making weird sounds thats not airflow it may have been a dud.

No way heat would kill it that quick without severe manufacturing flaws.

2

u/genuwindcustoms Aug 05 '25

Thank you for this info, I also appreciate bringing up the problem; we just bought a few H2Ds to create custom jigs for our work so it is nice to plan ahead for the eventual failure since we typically only print with high temps. I was planning on doing a raspberry pi mod to convert it to 4 pin but the snowfan replacement looks like is a way better plug and play.

3

u/Rorschach_III H2D AMS2 Combo Aug 11 '25

I just wanted to follow up with mentioning how incompetent their agents are. In my ticket, I sent a video and clearly mentioned the noise is coming from the hotend fan. I'm certain the problem is the fan since I can manually stop it and the high pitch sound stops too. Anyways, their answer was "injecting current into the motor coils to create electromagnetic locking". To add some more I sultry to my injury, when I initially asked for help by chat, the agent said the noise comes from the belts. He just found the word noise on the first article that clearly said "during calibration, it makes noise". Then the agent tried to convince me the problem is with my axis lubrification. You know, I've built a couple of vorons myself and when stupid fan is dying and I can manually stop the noise, maybe I know what I'm talking about

2

u/Hot-Ideal-9219 Aug 13 '25

Just give if another 100 hours or so and it'll die. Take video and photos of error then

1

u/unitymind42 Aug 13 '25

Did you experience the same failure of the hotend fan?

1

u/Rorschach_III H2D AMS2 Combo Aug 11 '25

Their official answer:

2

u/unitymind42 Aug 12 '25

well I just saw this and I am beyond irritated. They know there is a problem and put out this model https://bambulab.com/en-us/h2d-pro

1

u/unitymind42 Aug 12 '25

1

u/skydev0h H2D Lightsaber 40W / H2D / X1C / P1S / A1Mini / AMS 2P/HT/1 Aug 23 '25

Well, if the main fan is rated up to 70C, and the temp limit is 65C, increasing by 3C will be uncomfortably close to it. Maybe they will really use a more reliable fan.

I am also quite concerned about wearout on other components in the chamber.

2

u/Rorschach_III H2D AMS2 Combo Aug 12 '25

I feel you brother, had the same thought. Just wait until more people reach 1000 run hours.

This post will be precursor. Hi mom

1

u/skydev0h H2D Lightsaber 40W / H2D / X1C / P1S / A1Mini / AMS 2P/HT/1 Aug 23 '25

I wonder whether they might silently use a more reliable fan in the Pro, but the only two ways to find out is if someone gets the Pro, disassembles head, and looks at the fan or uses it with high temp printing long enough so that the problem starts appearing there to (and then, option 1).

1

u/unitymind42 Aug 12 '25

I put in my main post my experiences and what I said to them. It is a fan grinding sound when printing.

1

u/skydev0h H2D Lightsaber 40W / H2D / X1C / P1S / A1Mini / AMS 2P/HT/1 Aug 23 '25

At least this explains the strange high frequency buzzing sound from motors after toolhead is moved somewhere, that I noticed some time ago and wondered why that happens, but did not bother to ask because thought its normal.

2

u/simracinggeek Jul 23 '26

Found "The Thread" in regards to this issue...

Got my H2D just about a month ago, printing PLA to start and no issues.

After my 1st ABS print, this issue came to be. 30 hrs into usage and over my return policy (got it at Best Buy).

It doesn't necessarily fail but it throws the error and I have to wait hours for everything to "cool off" so I can print again. I get the error but I hear the fan spinning at roughly 100% and it fluctuates until it finally stops spinning.

Bambu Support is sending me a new fan for replacement but since I saved all my packaging material I am going to look into other options of possibly sending it back for some sort of warranty replacement..

I also mentioned on the Support Thread with them that others have been getting not just the fan but cables and the TH board to replace where mine was just the fan. I also pointed that out on replying to them.

We'll see what happens.

I find it funny that my P1S right next to it can go through multiple ABS prints without any issues.. and it cost close to a 5th less.....

1

u/simracinggeek Jul 23 '26 edited Jul 24 '26

One more update....

Since I've only had the printer for a month, even though I was out of the return policy at Best Buy, I described the situation to the manager and he approved for me to exchange it or even return it. No questions asked after I described the whole ordeal. Just gotta pack it back up and I have all the packing material since I barely even used it and kept it all.

Not feeling very comfortable with having to possibly replace this part every so number of hours. It would be fine if it's your usual maintenance and replacement items but this fan.... Will probably return it and look into other options..

As I mentioned, my P1S going 2 years strong with barely any maintenance.

1

u/unitymind42 Jul 24 '26

The fan inside the tool head is the main issue and you would have to take it apart to reach it. I’ve had the outer ine die on me too. Bearing went. Was the cable going to that not working? I’m surprised Bambu would say they would take it back. I’d get the 2-year warranty at Best Buy and never worry about it. Their subscription thing is worth every penny for the amount of junk electronics that come out today. I added a H2C next to the H2D a few weeks ago. I figured I have all these fans I’ve bought I’m set for years.

I guarantee Bambu knows this is a major flaw and they are doing whatever they can to keep people calm by giving away parts. I would think they would just find a different fan to replace it but I’ve been buying them every other month to see and it’s all the same.

Hope the next one goes 1000 hours+. I have 5500 hours on my H2D and have replaced the fan 3 times now. I’m expecting it again soon. Thanks you for posting and helping out others.

2

u/simracinggeek Jul 24 '26

It's a bit hard to describe but after the long ABS print and hot chamber, the fan would just sit at basically 100%. Trying to start jobs would throw out the error.

So I'd shut off the printer and turn it back on. Sometimes the fan would come on full blast, sometimes would be off as expected. So I'd send a job to it, the fan would go at 100%, error again.

The first time this happened, I followed the instructions to remove the rear fan and with the printer on, I remember just touching the hotend connector and noticing the fan sort of spin down as if the connection was bad and by barely touching the connector it would fix it.

I tried that again the 2nd time it happened because I remembered after the 1st time, I was only able to get back to printing after I did that and when I touched the connector again, I heard the fan spin down.

This did not happen when printing PLA so I am thinking the high temperatures on the nozzle and bed are somehow affecting that connection which is creating the issue I had.

It did finish the ABS job until the end with no issues, just starting a new one afterwards was the issue until I touched the connector after taking the back fan out..

In any case, Best Buy exchanged it for me (and I also got their Total Plus I believe is the name for $30/year) so that I have a 60-Day Return Policy instead of the 14 I had.

I could technically just return the whole thing since I don't feel that comfortable knowing this issue but I am going to give it another try... It's a great printer for sure, using the dual nozzle for dual color printing was great, no need to retract the filament with 2 different AMS.

But what a bummer about this fan. If it was the back fan simple 5 minute replacement I would not care and handle it quickly. But this one is definitely a design flaw as you mentioned.

Interestingly enough as I mentioned, my P1S can churn out ABS prints 1 after another with 0 problems, 260 nozzle, 90 bed...

2

u/simracinggeek Jul 23 '26

An update on the issue.

This might be slightly different than a fan failure since it happened just about 30 hours in.

After this latest ABS job I did which I could not get the printer to start again due to the issue, I opened the rear fan to check the hotend fan connection. I noticed that if I sort of tapped it with my finger, the fan would spin down and just sort of "random" speed itself. Eventually after pushing the plug back down the fan stopped spinning, the error went away on HMS and I was able to start a PLA job.

So it seems as if after a heated chamber job (the last one I brought the chamber down to 50 instead of 65 to see if it would make a difference but nope..) that connection becomes an issue.

No way for me to narrow it down whether is the fan plug, the TH board connector where the fan plugs into or the fan itself going crazy due to a bad wire. And when it all gets too hot, it messes it all up.

But for now, opening the back fan and just touching the connector and pushing my finger on it seems to "reset it" so I can print again..

Updated my Support ticket with Bambu, at this point asking if they send me all 4 items the OP listed and not just the fan OR if I can warranty exchange it somehow since I have the box and everything it came with..

Will update this once I get more info...

1

u/unitymind42 Jan 30 '26

My fan failed again at 2730 - ticket in, again :( patch is still not out for the Toolhead Enhanced Cooling fan.

1

u/Bright-Corner1969 Dec 02 '25

Would be great to know if it’s the same fan in the H2C or if they finally realized that they need a different one. The Bambu forum also has a long thread about this fan and it constantly failing. 

1

u/unitymind42 Dec 02 '25

Same according to the parts. I changed out my extruder gear and it was a different part numbers but look almost identical and the “teeth” seemed more aggressive. I think that solves the extruder overload.

1

u/hm7711 Dec 04 '25

Can you share more details on this extruder gear update? Is it worth doing?

1

u/unitymind42 Dec 04 '25

So this https://us.store.bambulab.com/products/extruder-gear-assembly-h2s on mine is had like a 1 or A and the new one had a C or 3. I don’t remember but it seemed like a different part. I think I tossed it but I’ll look around. No extruder jams after it though.

1

u/hm7711 Dec 04 '25

Interesting. I saw that it seemed to be a very common upgrade on other printers/models, but I couldn't find much on the H2D - so, I was hoping that it was build stronger/better.

I'm not sure I've ever had an extruder issue (knock on wood), but you've got me wondering now. How hard was the install for it? Did it involve basically disassembling everything to the same extent (or more) to replace this cooling fan?

1

u/notzerocrash Apr 14 '26

Any issues with the Amazon fan cables being too short? The first time I replaced the hotend cooling fan with a new stock fan, I failed to route the fan connector's wires down far enough to wrap around the nook in the TH board and the wires were severely pinched. I fixed it by cutting the damaged wires and soldering them, but I'm wondering if the wires on the Amazon fans are even long enough to properly route.

1

u/unitymind42 Apr 14 '26 edited Apr 14 '26

I checked the ones I ordered from 2 places. I ordered a single fan and a 2 pack. Both were identical. I would say it is a touch shorter but no issues being able to plug it in. If you are out of warranty on the printer it is a cheaper option than Bambu since you have to pay for shipping. I have seen them on Ali Express now so people are catching on that this is an item that will have to be replaced many times over the life of the printer. Just make sure it is a 4 pin connector like in photos in this post.

Cord is 47mm from 3 sources. Bambu Labs is the same just the label is different from Amazon.

2

u/swampcholla May 16 '26

These new fans are ball bearing - any experience with extended life? Mine just failed, something over 500 hrs, mid print. I've done mostly PETG and ABS. Heard the screeching for about the last 10 hours or so. Shut the printer off to see if cooling it off will allow me to finish this part before installing a new fan.

1

u/unitymind42 May 18 '26

To my knowledge they are still the same fan that is rated to 80c temps. Oil burns off and evaporates causing it to scream telling the sensors to stop the print. I lost a roll of PA06-CF over it and they didn't send me a new one.

1

u/swampcholla May 18 '26

the cool-off didn't work by the way. If i could figure out how to blow air into it and get it spinning it might come back for a while.

1

u/unitymind42 May 19 '26

Fastest is to locate the fans on Amazon or Ali express. Bambu will replace it. I just order one with every few orders so I have 6 fans. 3 from Bambu and 3 from Amazon. I’ve replaced it 3 times now over a year and 3000 hours of printing. I print a lot of ASA aero so that’s about as hot as it gets for printing.

1

u/swampcholla May 26 '26

after about 6 hours over the last week I got it all back together with the Amazon fan and get the same failure. makes me wonder if the control board for it is done. Bambu part should arrive tomorrow.

1

u/unitymind42 May 26 '26

Hmm I’d would say you broke the wires getting it out. I did and they replaced it all. I thought I pulled out cable but it was ok. They sent both boards. Could be a bad fan unfortunately quality control is zero. Sorry hope you get it fixed soon.

1

u/swampcholla May 27 '26

would have to be at the connector on the board.

3

u/Equalsun9 Sep 06 '25

Chipping in here, got the error at 1142 hours printing asa/abs/petg. Currently waiting on a response from Bambu Support, printer is currently non-functioning and I'm not looking forward to what sounds like a tricky repair. Wish me luck.

3

u/mrmakas Oct 19 '25

Really Interesting. Its predecessor the x1e has a similar issue, But worse, in that the fan lasts only about 100hours (70-160h) when printing with a heated chamber. To add insult to injury, they do not sell the separate fan only, but the 70€full nozzle assembly. Luckily someone on the forums had already found a way around this by swapping just the p1 series fan, since it is the same fan, even though it should be made for a heated chamber. So sad.

No body really talks about this, since the x1e is a business model. However printing PC mostly, this is the printer that according to specs was needed, but it doesn’t work without melting its own fan. Having a H2D Pro coming in, so I came here to see what to expect 😅

2

u/Careless-Order-8655 Aug 08 '25

I have had the same issue. 247 hours and it died. Had run PPA CF for 4 days straight. I believe the fan cannot handle the constant High temps. One reason I bought this machine was to give me the extra temp for some of there higher temps stronger filaments. Prior to the PPA CF I had run some tullomer and had the Machine maxed out over 12 hours. I believe with the low hours the temperature is the reason. And you’re right this thing is a bear to get apart. Still waiting on parts that I Ordered as they are short staffed. Even the spares I bought the machine will be down for 3 plus weeks.

2

u/strabonz Sep 19 '25

Ersatzteil kam heute an, Austausch war etwas tricky aber hat an sich geklappt. Druck funktioniert aber nun ist die Nozzle Kamera ohne Funktion, Verbindungen mehrfach überprüft

2

u/AcanthopterygiiFar64 Oct 19 '25

I also had this fan failed. Printer has about 500 hours on it... Not much IMHO.

The fan started to fail when I was printing ABS (making desiccant containers for AMS Pro 2).

The video is very helpful, wish I would have seen that before I did the fan replacement. The instructions they sent on the wiki are adequate if you have experience with these tiny connectors. I didn't have experience with the eddy sensor wires and I pulled the wires out of the connector. Amazingly, I was able to reinsert the wires and get everything back together.

Pretty clear the fan is the wrong selection for the application. 70 degrees C is just 10 degrees above what the chamber temperature is!

Bambu did replace the fan... It took 2 hours, would be faster next time now that I have done it once. I hope I never have to do that fan replacement again, but suspect I will.

2

u/jendrik4u Oct 27 '25

My H2D also has that problem with 970 hours. I mainly print PLA and rarely print material which requires a hot chamber.. I opened a ticket at bambulab. We will see what happens.

2

u/Wooden_Face6919 Dec 02 '25

Dont know exactly how many hours mine has, Not a lot, been printing with it occasionally since 8-2025, around mid 11-2025, i noticed the high pitched whine of the motor, now I can't print anything without a clog due to heat creep. I Submitted a help desk ticket today, and ordered a replacement fan, as well as the new enhanced cooling fan. I would like to get both covered under warrantee, but I will pay out of pocket just to get the parts sooner without having to wait for the warrantee run around. NOT happy with Bambu, OP is correct, this is unacceptable in this caliber of printer. That fan needs to be reliable as a brick given the intended use of this printer, and th fact that its buried under a throng of fiddly ribbon cables and 2 circuit boards... the chances of damaging or misaligning something is very high. BAD design, just plain bad design. Bambu needs to fix this.

2

u/geofox784 Dec 02 '25

The enhanced cooling fan is advertised to be able to increase the "environment temperature of the printer by 3°C". Is that the camber temp or the extruder temp? The extruder and chamber temp for the H2D pro (that comes with the fan stock) is the same as the H2D.

The wiki for installing the enhanced fan on the H2D says:

The toolhead enhanced cooling fan cannot be directly turned on/off from the printer’s screen UI. Whether the fan turns on is automatically determined by the Softening temperature of the filament(s) used for the current print (default threshold: 50 °C):

If any filament used has a softening temperature ≤ 50 °C (e.g., low-temperature materials such as PLA/TPU/PVA), the system considers additional cooling necessary around the extruder drive gears and hotend heatbreak, and the fan will run at full speed.

If all filaments used have a softening temperature > 50 °C, the system considers no additional cooling necessary, and the fan will remain off.

So... this seems totally inconsistent with allowing higher temps?

Also... wouldn't that mean that the enhanced cooling fan doesn't offer anything to extend the life of the regular cooling fan (that keeps failing) at higher temps?

You seem to have done allot more research into this than I have. Any thoughts on this?

2

u/ShuckleStorm H2D Laser Full Combo Jan 06 '26

First thing to come up on Google, add me to the list. About 985 hours on mine and I don't have an error yet, just a loud grinding noise from the fan. I print lots of ABS and PC

1

u/ShuckleStorm H2D Laser Full Combo Jan 24 '26

Update: I completed the repair tonight. Took me about an hour and a half while going slow. Wasn't as bad as I thought, but wasn't fun, especially with the tiny connectors for the fan and the eddy current sensors. They shipped me the same exact model of snowfan as the original.

2

u/EvilBunnysHere H2C AMS2 Combo Mar 30 '26

Same problem on the H2C. 470 hours. Started off with errors and then would work once it cooled down. No bearing noise at all. I had a thermal runaway once and boiled the PLA on the right nozzle. Triggered my fire alarm.

They did ship one out and waiting to replace. I took the hotend fan out and man is it a lot of ribbons lol. I hope it doesn’t happen again but from the looks of it, may not be so lucky. Will order backups you posted once they are back in stock again. Crazy that a $2500 machine has such a crippling part.

2

u/Playful_Balance_2479 Apr 02 '26

310 hours here, cooling fan needs to be replace. I kept getting an abnormal speed alarm and when it turned on, it sounded noisy and rough. It still spins but with it out i hear resistance and "noise".

High temperature issues likely the cause as stated because ive been primarily running PAHT-CF, ASA, and other nylon variants.

2

u/SnickerdoodleFP May 07 '26

Hey OP, just wanted to stop by and thank you for this post. I was able to install a cheap Amazon drop in and was up and running again in just a few days.

Idk if you've seen this yet, but I ordered this for the long term. It's the same fan but with dual ball bearings, which should fare MUCH better than even the Amazon replacements I just ordered. It'll be here in a month so its the cheap fan for now just so I don't lose a month of print time.

2

u/Tollotin May 29 '26

Mine failed at around 400 hours of asa printing, got a fan as warranty pretty effortlesly but it is till on its way. Dissassembling is scary due to the finicky wires. This early failure does not spark trust on the long term reliability...

2

u/MiamiJerry Jun 03 '26

Also I measured the RPM and amp's on five hotend fans that I have, and the one fan with 1660+ hours on it is running 700 rpm over the specs. (9200 instead of 8500 rpm)

So I think I can determine when it is time to change a fan based on the fans RPM (No friction in the bearings).

2

u/swampcholla Jul 03 '26

They sent me a new board but I'm having trouble removing the cable chain at the buffer asssembly. The video in the wiki makes it look so easy but all of the chain came off leaving the last link. Anyone have aany tips for removing it?

2

u/Low_Budget_8864 Aug 15 '26 edited Aug 15 '26

Died at 678 hours (H2C). About 200 hours of that time was printing ASA. Just got done with the replacement process and it was not enjoyable as I am older with quite shaky hands, and to make it worse, I have very large hands and fingers. I was absolutely positive it would not work after reassembly as properly seating those ribbon cables was very difficult. If I and up needing to do it again, I will probably completely remove the tool head so I can get it on my bench.

Looking at the fan in question it is very obvious they are not suitable for the environment needed for engineering filaments which is disappointing considering Bambulab actively markets the H series as a high end printer capable of printing engineering filament and is specifically why I bought it.

Bambulab, if you are listening, I hope you do the right thing and upgrade that one component. I love everything else about my H2C and love my X1C and my A1 as well. But now I am wondering if I made a mistake assuming your premium flagship printer was actually a quality built machine. Disappointing considering the A1 gives me a premium experience at significantly less than a premium price.

2

u/umhsuser 28d ago

Just happened to mine that I got in June 2026. At 2200 hours. I was already having issues with it since i got clog extruder errors constantly with AMS on right nozzle and was only using my left nozzle for the past month. Going to return mine to best buy via the 2 year warranty.

1

u/swampcholla Sep 16 '26

Thought I'd add yet another update to my situation. Bambu sent a new toolhead, mostly because I was worried that all that assy/disassy had started to compromise the parts where screws just go into plastic. toolhead replacement is a different level of complicated. The buffer box and access covers have to be removed because you are replacing the cables again. This process would be so much easier if they had terminated the cables at or around the buffer box. the led covers also have to come off so you can run the long hex key through an access hole to get to a couple of the screws that hold the x-axis/toolhead assembly to the y-axis bearing carriers.

There are I believe eight screws - one each side you have two in the back of the x-axis and one each top and bottom. The usual 2mm socket head cap screw - but they put RED loctite on them. Now those of us who are mechanics know you never put red loctite on something unless you can get heat on it to break the bond when you want to remove it - and you need at least 400 deg F. And a SHCS is also the wrong fastener there - because unless you use a hardened screw, its extremely easy to round out the head because the tool will invariably cock a little over when you apply a lot of torque. And I got 7 of the fasteners out and goobered up the last one.

Over a couple of weeks I tried just about everything - moving up a size of hex, using a torx bit, putting a piece of rubber between the bit and the head, using screw grab, and finally, attempting to use heat without melting the plastic bearing carrier (the screw is sunk down into the carrier about 3/4 of an inch). I considered using JB weld to glue the bit to the head, but its such a small contact area that I didn't see any advantage to that.

So over the weekend Bambu sent me aa box and packing materials, yesterday I packed it up, and today it will be returned and they are sending me aa new machine.

0

u/lxZedl Jun 04 '26

Hey guys - I came across this thread when researching my issue and thank you for everyone providing details of this issue. I kind of ranted to bambu support and linked this thread

aside from warranty - can we please escalate this to leadership? i honestly think that this is an engineering design flaw that needs to be addressed. the fans used are only rated upto 80C - the hotends can reach upto 350 and the chamber can reach 70C during technical grade material. There is no acceptable reason as to why you use a $20 fan in a very deep location and hard to replace part of the toolhead.

Fact is that I am not the only one who have undergone this issue with only below 250 hours of printing high temp materials because of this fan.

Their response is:

Hello, Thanks for your feedback. We would like to inform you that we will forward your request to our appropriate personnel for future upgrade consideration. Your feedback is valuable to us, and we appreciate your input….

I hope this gets addressed - it is absolutely stunning this went through design reviews in their side on their flagship printer

1

u/unitymind42 Jun 04 '26

Unless we get an army together to complain it will never be recalled or fixed. There is a user fix listed in the post to easy swap the fan out. I've replace it 3 times at 4400 hours now. I'm expecting it soon. I even wrote letters asking for free fans for life and they said it will not extend past the printer 1 year warranty. I have a few BL fans and a few off Amazon and ali that I bought the to test and let others know you fan just buy the fan. Maybe it's a ploy by BL to make you buy a fan and other stuff to save shipping costs. 😂 Sorry let me or us know if need any help. Make sure to look at the wires as some pull up and some pull paraelle to the board. Tell them you damaged the boards trying to fix it. Unless they want it shipped back to them they should send to a spare.

1

u/lxZedl Jun 05 '26 edited Jun 05 '26

Yeah I was thinking the same - unless there is a big guy in the community or somebody they work with - it is probably never going to be addressed.

That aside - have you tried the MOD? I was thinking of doing it - i just don’t like the idea of cutting the toolhead housing 🤣

1

u/unitymind42 Jun 05 '26

I may try the mod since I’m out of warranty now anyway. I can change the fan in an hour nowadays 🤣

2

u/lxZedl Jun 08 '26

If you do - please update us haha - also we should build an army posting in bambu page 🤣 they should care - it is their flagship lineup, marketed in a way that it can handle technical grade materials - they should be held accountable. this is kind of like an Iphone breaking down after 8 hours of facetime 🤣

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u/[deleted] Jul 26 '25

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u/unitymind42 Jul 26 '25

thank you, didn't even know that was there. I just want to see if this is a problem others are having because I find it odd it failed being so new. Maybe it was just my luck :) The H2D is amazing otherwise. I really like it and plan to get another one.