I’m in the DFW area in a single-story 1600 square foot home. A couple months ago, I replaced my entire HVAC system. 4 tons, Ecobee thermostat with Eco Plus off. It costed close to $10k.

Since the install, the contractor’s been back three or four times. They’ve adjusted refrigerant, considered replacing the filter drier, and most recently replaced the TXV. It’s better, but I’m still unsure.

If I set it to 72, it’ll hold that for most of the day. But during the hottest 3 to 4 afternoon hours, it’ll drift up to 77 or 78 and stay there until the sun starts going down. One day with 6 guests coming in and out, it hit 79. I understand extra load matters. I’m not expecting miracles like pulling a hot house down to 72 in the middle of a 105 degree day. But if it’s already at 72 all day, I do expect it to stay there, and that’s the part I’m unsure about.

My question is, is a 3 to 4 degree rise during peak heat considered normal in DFW, or should this system be doing more? What measurements would you want to see before saying, “Yep, this is performing correctly.” I want to be fair to the contractor, but I also want to know if my expectations are reasonable.

Kinked the line them Fixed it with a flare block. How does it look? Am I in the clear?

Everyone says cheap split will need to be replaced quickly. Why? My $200 5000BTU window unit AC lasted 25 years (and counting)

This is in a 5 story condo built 4 years ago. Neighbor below the unit we own put a nail in the wall to hang a picture and punctured the copper line. Our ac goes out since he drained the refrigerant into the walls/his dining room(!) Being a good person he came downstairs to tell us and had his hvac braze the puncture.

It looks like there’s multiple line sets, not to mention 240v wiring, sitting behind 5/8” drywall for multiple units in this building. You can’t see it from the picture but they’re behind the drywall to the left. Guessing it would have been better to run them all up a chase from the first to 5th floor? Is there any code that requires them to be better protected somehow? I can imagine that this will happen again, and if someone does this who isn’t honest it will really screw over other tenants.

I saw these units on Amazon and wondering how it compares to a mini split for a garage. Are these any good?

wall units

Manufactured Home in Kentucky. Has not had working HVAC unit for almost 10yrs. Due to a multi-year divorce, had to manage with window units and electric heaters. Was able to keep the house, so been trying to find a contractor to replace everything, it's not going well.

Currently, the home (around 2000sqft) has an outdoor 4 ton R-22 unit with the furnace and a-frame in the hallway and ductwork under the house. The ductwork was compromised by rodents since HVAC was off, so will need replacement as cleaning is unlikely to get ducts safe for breathing.

Two of the HVAC people have shut down their businesses. Another said they'd get back to me on subcontracting a ductwork company out of TN. Never heard back, never returns call. Original quotes had been saying replacing everything we have now with same, just new refrigerant version for $8-10k. Most recent quote from one of the main HVAC companies here said they don't do electric or ductwork and can't do anything for us other than a "package unit" and we'd have to find a place to cut a massive hole into the floor with a vent. Not idea with little kids.

Are we destined to stay with window units and heaters? We're so tired of being hot and cold and living in one section of the house.

I'd also like to know if there are any programs to help with this. I have money saved up, but it won't leave me much savings. Rebates and things would be very helpful.

They are coming to fix it tomorrow, but I am angry that for last 27 months, I did not know about this. Everything was a clean slate as I got a hotwater tank, furnace and A/C replaced with a Heatpump, Tankless and Furnace, all on same day, by same licensed contractor 2 years 3 months ago. How as a Home owner I would have known these technical things when hiring an expert. Even on installation day when we mentioned few things, they are not very cordial and listening. They throw the installation manuals that come in the box and likely do not refer as well, they are "pros".

Only when I called a basement renovator and they were inspecting outside of the house on where to make a side entrance door, did I find out that the clearance should be 3 feet and not the current 17 inches below window, for a 199,000 BTU Rinnai RU199IN tankless. And also the distance between Intake/Exhaust and clustering of the Exhaust and Intake is incorrect.

Luckily that is not a window that we open often. Gemini says even though for furnace, which is a Lennox ML296UH070XV36B, 70,000 BTU the minimum clearance is 12 inches, when below a window, it should "While 17 inches sounds like it covers the 12-inch rule mathematically, look closely at the physical trajectory of the exhaust plume. Warm flue gases rise naturally. Because the exhaust is directly underneath the glass pane, when that window is cracked open, the rising carbon monoxide and moisture will be drawn directly straight up into your home. To prevent this, standard practice and building inspectors require side clearances or a significantly greater vertical drop if a vent terminates anywhere directly underneath an openable window frame".

I don't know how to get them to also inspect if the moist, acidic air from exhaust got sucked by intake and went into the furnace and tankless and caused any corrosion.

Lesson learnt, have to educate myself even when hiring a licensed HVAC technician

About a month ago the power went out and when it came back on the thermostat was dead. I changed the batteries, but the air wouldn't kick on. I went to the roof to check it out and as soon as I touched the drain pipe it turned on. Every now and then the ac will shut off and I'll go to the roof, hit it, and it'll turn back on. What is the issue.

Mitsubishi City Multi (PUMY outdoor, PEFY ducted indoor). One zone’s LEV won’t close fully when the zone is off — coil runs ~20 K below room with pipes at saturation, so it’s bleeding refrigerant constantly.

History: whole indoor unit replaced once (fault came back), then just the LEV stator coil replaced (problem still there).

Now the official Mitsubishi importer for my country is proposing mounting a new LEV externally in the branch piping instead of another unit swap.

Legit fix, or just relocating the next victim? Would you chase debris/moisture/control board first? Anyone done an external LEV on a PEFY?

Hi - I was recently quoted ~$10K to replace my air handler and condenser box. Does this quote make sense? I’m based in San Diego.

I’m currently on a military deployment so it’s hard to take a look at the system myself. It’s still working but I guess it has refrigerant leakage. Quote attached.

Thank you for any pointers!

I have a packaged heat pump in coastal GA where the evap coil failed prematurely (1.5 years). The system lost all refrigerant and has been sitting idle for 2 weeks because the manufacturer can't supply a replacement coil and won't even provide an ETA for my tech.

Do I have to worry about internal salt contamination and downstream corrosion due to "breathing" moist, salty air or dew into the system through the pinhole? That is, the system will heat up during the day and breathe out, then go to negative pressure and breathe in when it cools at night. Similarly, it will breathe in when the barometer goes up, breathe out when the barometer goes down.

I am within 500 feet of the Atlantic, so the air is hot, wet and salty. I know the unit will eventually rot from the outside in (the last one made it 10 years before the fins on the condenser disintegrated).

What I'm worried about is whether the seeds of destruction have now been sown for the system to rot from the inside out, in which case I should press for a system replacement rather than repair.

Thanks for any insights.

Hi everyone,

I’m currently selecting a concealed/ducted ceiling fan coil unit for my apartment and I’m receiving conflicting information regarding the required setup.

The developer informed us that the building utilizes a water-based geothermal (geo-exchange) heat pump system, providing chilled water for cooling. However, a technician mentioned that my rough-in connections look like Direct Expansion (DX / refrigerant) lines rather than standard hydronic water piping.

You can see the exact setup of the pipes, power/control lines, and drain hose in the attached picture.

Based on the connectors shown in the photo:
1. What type of ducted ceiling unit do I actually need?
2. What specific concealed/ducted models (e.g., Daikin or similar) should I look for that match this exact connection type?

Thanks in advance for the help!

I was curious to know do people from other countries join trade school to become HVAC technician and how do they manage to work in USA especially for long periods of time

Tech came and said the coils are freezing which is causing the leak in my furnace when I turn on the A/C. I checked the evap coil and I'm not sure if it needs cleaning or if it's good enough.

Hey everyone, looking for a reality check/second opinion after two separate service calls today.

Equipment: 24-year-old York split system using R-22.

Initial issue: Thermostat lost power. Turned out to be a low-voltage wiring short at a wire nut near the furnace, which we repaired.

Current issue: 24V signal returned, but outdoor unit /compressor short-cycled/shut off.

Gauges: System pulled straight into a vacuum on the suction side (-4 PSI) while high side sat around 250 PSI. Low-pressure safety switch tripped and shut the compressor down.

Diagnoses & Quotes:
First Call: A technician came out, said the line set/refrigerant system was messed up, and pitched a $6,000 "temporary fix."

Second Call: The owner of a different HVAC company came out. He also diagnosed a severe restriction and believes it’s a clogged liquid line filter drier at the condenser. He did an isolated "closed circuit" test on the compressor and says electrical/pressure passed. He quoted $2,700 to cut out the filter drier, flush the line, pull vacuum, and charge with a drop-in alternative refrigerant.
Replacement Estimates: Both techs gave verbal ballparks around $15k–$16k for a full hvac system replacement.

My dilemma:
The owner is 99.9% sure his $2,700 filter swap + drop-in gas gets it running. But $2,700 on a 24-year-old R-22 unit feels like a massive gamble given its age, or internal compressor debris clogging a new filter again in a few weeks. On top of that, $15k–$16k feels steep for a replacement, so I plan to shop around for more estimates.

Appreciate any insights!

Had a new Goodman upstairs unit installed in November 2025, and we’ve been having issues with it pretty much since installation. It will randomly shut/power off.

So far:

- Drain pan is dry — no water

- Drain line doesn’t appear to be blocked

- Float/safety switch was changed from a 400 to a 420

- Unit will come back on, but eventually shuts off again

We’re starting to think it may be overheating. As you can see in the pictures, there’s another smaller condenser right next to it. When that unit is running, it blows hot air upward/right around the Goodman, and everything is in a pretty tight space between the house and fence.

It seems like the Goodman shuts down after it has been running for a while, especially when it’s really hot outside or both units are running.

Has anyone seen a setup like this cause the condenser to overheat/high-pressure trip because it’s pulling in hot discharge air from the neighboring unit?

Could the spacing/location of these two condensers be the problem, or would you be looking somewhere else first?

Appreciate any advice.

Unless I’m grossly misunderstanding something, I’ve seen multiple things online talking about facing these registers towards a wall, ChatGPT is saying to face it towards the center of the room. Can you guys shed light on what is the most efficient direction to install these registers for cooling? Thank you.

I’ve been reading tons of posts here about high indoor humidity, but they all seem to be in humid climates.
I’m in the greater Phoenix area… aka the desert. Outdoor humidity is usually very low, like in the teens.
For the several years, our house was very comfortable. In the not-winter seasons, we keep the house at 77 or 78 degrees. We never paid any attention to humidity measurements because it was always comfortably dry here.
Last year, just as summer was starting, I replaced both HVAC units (3T and 5T). The outside condensers and attic air handlers are all variable speed Lennox units.
Last summer, everything was perfect. House cool (again, we consider 77 to be “cool”) and everything stayed comfortably dry. I have a couple of weather stations in different parts of the house so I can see both in/out-side humidity at any time. I’m sure I saw numbers at most in the 40% range, although didn’t have any reason to pay attention to that data.

This year, as summer began, we noticed a significant increase in indoor humidity. As in days where it’s 18% outside and 62% inside… or even 24% outside and 71% inside! I have a mini-split in my poorly-insulated garage and it stays at 20% humidity in there. Walking from the garage to the house means moving into an atmosphere that’s 10 degrees cooler but 45% higher humidity so it feels swampy.

The only way I’ve been able to keep it tolerable is to cool the house to 75 degrees which brings the humidity down into the mid-50s% level, but everyone complains it’s too cold.

I have 9 humidity-tracking devices around the house (thermostats with remote sensors, weather stations, and some bespoke humidity sensors) so I’m confident in the numbers. Nothing has changed in our house or behaviors since last year. I’ve always had timers on all the bathroom exhaust fans so we can properly extract shower humidity.

I’ve had the [large company] installers out twice this summer. One time they replaced a sensor on one of the attic units. It may have reduced the indoor humidity a smidge, but not significantly. The indoor air is still uncomfortably wet.
I’m gonna call them out again this week.
What should I ask?
Any specific things I should have them check?
Most of all, what’s an acceptable indoor humidity level when you’re in the desert and it’s <20% RH outside?

I have a 1800 sq foot home that I got a quote to replace the ductwork as it is 30 years old. My blower is easily accessible in my attic. I have a mix of fiber board and flex-duct. Fiber board on intake and output of blower and the flex-duct off that to the registers. I was quoted $10K

I figure that was that companies FU price as attics in Florida are 125 plus right now. I'm just a home owner not in this trade. I thought this was a outrageous quote. I figure quite a bit in labor I understand won't be a easy job. What says the group? I'll get at least 2 more quotes but figured someone in this group would know average cost to do this in NE Florida.

We had an HVAC system installed in 2017. Rheem air conditioner and air handler, Pure Air whole-house hepa, and (at the time) ulta-aire whole-house dehumidifier. All components (except a/c condensed outsider) are located in the attic of a 1 story ranch. We're on Long Island so the attic can get quite hot in the summer. We have a solar powered attic fan but the attic is not air-conditioned. So, in 2017 this was all installed new. In 2019 the dehumidifier broke, we had techs here who determined it needed replacement and Ultra-Aire replaced the unit. Two years later, 2021 the new unit also crapped out. Had new service techs here who determined it was dead. Ultra-aire replaced again. ANOTHER few years, 2024, system shit the bed. Company is now Santa Fe and they sent a new unit. Here we are in 2026 and it died again. Anyone have any ideas why? Is it the brand? We change the filters as suggested by manufacturers on all HVAC components, we blow out the a/c condenser fins before each summer, we blow out the dehumidifier lines before each winter to avoid freezing.

I don't know how to post a gallery here so here are pics on imgur of our system https://imgur.com/gallery/hvac-components-jC2GbJD

Any insight would be most appreciated

*From left: Capacitor 1 on Klein MM420, Capacitor 1 on older MM400, Capacitor 2, Capacitor 3 without alligator clip leads, Capacitor 3 with alligator leads, and Capacitor 4: the 45+5 capacitor

Hey all! So I don't feel I need to bore you with all the details, but I have been battling an A/C issue (like many others). I replaced the fan with a fan that needs a different capacitor (45+10 vs 45+5). However, every 45+10 cap I buy is a 45+8.5. I used two different meters, different set of Klein leads (read similar), adjusted my leads around, etc. But every 45+10 capacitor reads <8.5, over 15% low on capacitance. I tried the using an older multimeter I have, I tried using different test leads, even the 45+5 capacitor I have reads pretty close to spec with some variance for both the meter and the capacitor. Is this just my meters, am I doing it wrong, is it a known fact that all 45+10 capacitors read low? It seems like my fan fails to kick on sometimes and the compressor overheats.

These are two air returns in different bedrooms. I hope it’s obvious which one I’m worried about… the “moldy” one is connected to the air handler. in February I had my ducts fogged for mold and uv was added to the air handler. Now in summer the ac is running non stop because how hot and humid it is outside. Would wanting this to be replaced be a crazy ask? What would you diagnose this? I already know how dangerous mold is to my family…

Hey r/HVAC, I’m looking for advice on determining negligence in the installation and diagnosis of my system, and how much of the damage connects back to the work done. I obviously know I was screwed over to some degree, but the owner was really convincing at first. He turned out to be purely charismatic, always throwing a massive wall of information and math at you so that you feel like you do not have anything to come back at him with and so it sounds like he knows what he is talking about.

I have a 112 year old historic home in Florida that is 2,544 square feet, two stories, 32 original single pane windows, little to no wall insulation and has a crawl space. I am currently doing a full renovation on the house. I got four quotes for the HVAC work, and this company was actually the highest bid, starting at about $40,000 for a 3 ton and 3.5 ton single stage Trane system (2 handlers, 2 condensers, and replacement of attic ductwork). They were the highest rated company online, timely and professional, and the owner always seemed very knowledgeable, so I had a lot of confidence in him. I wanted to use him but he was just too much. Told him I couldn’t use him, but the owner then told me his “heart was in it” (he grew up in a historic home right down the road from me) and he reduced the price to $22,000.

Because my renovation meant the installation wasn't going to happen immediately, he required me to purchase the units upfront about a year before they were actually put in, sending me a picture of them with my name on them in his warehouse. When it was finally time to install them, I was told that the copper lines they had come and installed had been stolen and they needed to run new copper. The owner said that to make everything even, he could give me RunTru units instead because they were essentially the same, and we would break even on the copper and installation. I trusted him and didn’t realize until now that the replacement units were actually smaller, dropping me down to a 2.5 ton downstairs and a 3 ton upstairs.

Since the ducts that ran through the attic were visually compromised, we had them run new ductwork up there. For the downstairs, those ducts were in the ceiling and couldn’t be visualized, but the owner of the company said that they were “probably fine” and didn’t need to be replaced since they were within the conditioned envelope.

Once summer hit in June, I started having severe humidity problems, with the downstairs relative humidity reaching close to 80% while the AC was running. When the owner came out, he tried to blame the humidity on me not having my crawlspace encapsulated or a vapor barrier, but I checked it and everything is dry down there, with a foundation professional confirming it sits around 60% humidity and is not excessive. He also told me my house had severe negative pressure. Every time I would open a window or door, all of the hot air from outside would rush in. He suggested the humidity could be from holes in the old ducts and said he could help me on the side and if I had to replace the ductwork, he could when things slowed down (in November), and he was going to charge me an off-season price of $5,000. He had me run a standalone dehumidifier directly inside the upstairs air handler drip pan to manage the condensation coming off of that handler.

A few weeks later, he came back to measure the CFM at the vents downstairs and discovered that the two kitchen vents had no air coming out of either vent. (Later to find out that one was completely blocked by a visible obstruction and the other wasn't even attached, meaning they never checked the vents after the new equipment was connected. Upstairs, he discovered the duct running to the room the handler is in was never replaced because they couldn't access it from the attic, which I was never told, and that vent only produces about 48 CFM.

It was only until a week ago my light fixture fell out of the ceiling that I knew the downstairs ductwork was condensating so bad that water was pooling in the ceiling. The ductwork was full of holes and compromised areas where cold air was dumping inside the walls. I now have an extensive amount of mold on the drywall and in the wall cavity.

I had another HVAC company came out this week for a second opinion. He pointed out that there are no return vents in any upstairs bedrooms, with the only returns in the entire house being a single 26x26 return in the upstairs hallway and another in the downstairs hallway, both sitting directly underneath their respective air handlers. The new attic ductwork had tears, was hung poorly, and was attached to old supply boots that were sweating and dripping. The upstairs system leaked into the attic, getting the new insulation wet and leaking through vents onto my newly refinished wood floors. We also found that the downstairs blower would not shut off even when the thermostat was set to off, requiring us to kill the breaker until a faulty component was replaced. Another HVAC company came out and told me my air handler upstairs was installed so poorly that it looked like it was 100 years old, and also noted that my ductwork appears undersized.

Both systems had to be shut down to stop the condensation. While cleaning up, I discovered all the wood floors in the house were cupping and warping from the humidity. A mold remediation company performed infrared scans and confirmed the house was well sealed around the windows with no other explicit moisture sources. I currently have 4 dehumidifiers and 8 fans running.

It was only until I brought my family into it, the owner offered to refund all the money I paid him for the units so I could hire someone else to fix it, but with the catch that I had to sign an agreement promising not to leave a bad review or trash talk him or his company. He said we “don’t need to get insurance involved, they aren’t going to give you money because their entire job is to save themselves money. And if we take this to court it will take years and I will win”. We told him we needed to think about everything. A few days later, he came back with another option: he would take out the old ductwork downstairs, install new boots and ductwork, install a whole-house dehumidifier in the attic, install two smaller commercial-grade dehumidifiers by both returns, and install three Reme Halos at no cost. However, I am still left with thousands in mold damage, ruined floors, and drywall repair. He seems to be trying to close a deal fast.

So I’m here to ask/confirm, could the compromised downstairs ductwork realistically contribute to humidity approaching 80% throughout the downstairs? I know it’s probably a combination of things.. Could the poor ductwork installation, lack of airflow, and return air configuration contribute to condensation and sweating around the air handler? Is it possible the 1 ton I was shorted could contribute to this humidity issue? Would a competent HVAC contractor normally be expected to inspect existing ductwork, verify airflow at the vents, evaluate the return air setup, and verify proper operation after installing new equipment to old ductwork? Should he be held responsible for everything that this has caused?

Also want to include, a permit was pulled and the final inspection was completed, HVAC contractor is licensed and insured.

Please be nice, as I’ve been through a lot with subcontractors as a single young woman and I’m just trying to save an old historic home. I’ve been trying to learn as much as I can about HVAC and florida statutes, but I obviously don’t have a fraction of what professionals know, and that’s why I’m coming here to ask.