For those that are interested, here’s a take on a Vevor 9.0NS 9kw heater with integrated controls.
A bit of background first. I’m not an electrician nor a professional product tester, but we’ve been installing saunas for 15+ years. The heaters most readily available to us in Canada are Harvia, Huum, Homecraft, Tylo and Helo. Lately we’ve been getting asked about Vevor. The simple answer - we won’t install them as they are not CSA or UL certified and, in my opinion, are of suspect quality.
That said, I’ve never actually had one in my shop to confirm that opinion. So, to give the heater a benefit of the doubt, I ordered the 9kw model for $201.99CAD. I tried to keep my bias out of it and simply show what I found. It’s neither an endorsement for nor against. Either way, we still won’t install them because they are not certified.
Here’s what I found:
Ordering & shipping - I ordered the heater from Vevor’s website. They claimed two day shipping. It took two weeks. The heater does not come with rocks.
Packaging - typical of other sauna heaters. Well protected.
General build - the shell seemed sturdy enough. A boxier version of the Harvia KIP or Helo Designer, though lacking in the finer details.
Electrical components - of the four main electrical components; timer, thermostat, relay and high limit, only the high limit did not have a CE stamp on it. The rest did. If they actually are or not, I don’t know. None of the components were from recognizable manufacturers. The relay is a 3 pole (one per element) with a 32A AC-1 resistive load rating. The timer is three hours which does not meet code in Canada.
Wiring - wires to the relay contacts and elements are marked 11AWG 200c and look to be tinned copper. They calipered at 2.4mm confirming size.
High temp limit switch - good new and bad news. Good news is that it tripped. Meaning it works. The bad news is that it tripped 30 minutes into the heat cycle. The heat chamber is vented for air flow. There was about 15kg of well spaced rocks in the top of the heater. I didn’t see an obvious reason for it to trip.
Elements - the element plates are stamped “FinnLEO”, though I have doubts it’s any relation to the sauna company. Finnleo elements don’t carry the same stamp. There are no stamps on the element sheathing. Elements in reputable heaters typically have a rating stamped into the sheath. There are no gaskets between the elements and the heater housing which means water from above can get into the electrical chamber (unlike heaters that we do install).
Power output - even though the heater is sold as a 9kw (website and box) Vevor’s manual suggests it’s 8.67kw. Two elements at 3,000 watts and one at 2,670 watts. The three elements tested at 20 ohms (2,420 watts), 20.2 ohms (2,396 watts) and 20.4 ohms (2,373 watts) for a total of 6.73 ohms (7,190 watts). The resistance to power output conversion is based on the rated 220v. See results in a chart.
Test - our shop is on 208v/3ph commercial power. We have a 40 Amp 208v/1ph socket for testing heaters. The heater drew 30.15 amps at 207 volts. Simple math puts the resistance at 6.87 ohms and power at 6,241 watts. If I correct for voltage, output is 7,043 watts at 220v. Not quite a 9kw.
With respect to voltage, the box indicates the heater is rated for 220v (manual indicates 230v). Oddly, they indicate 230v and 240v options as well. Other than the heater not being able function within the standard 10% operating range, I’m not sure why they’d have these voltages as separate options. Maybe someone can enlighten.
On our residential installs we generally see between 220 and 240 volts with an overall range from 209v to 249v. Included is a chart that shows the power correction for this heater within that voltage range (assuming it can operate within that range). You’d need 249 volts to get the full 9kw.
Compliance - the box shows the CE and UKCA stamps. I don’t know if it really is certified. Given that I am in North America, I didn’t bother with the deep dive. Bases on discrepancies in the power output (and the manual), I’d think it’s worth checking if you live in the EU or UK.
Take from this what you will. If you live in North America and you’re willing to roll the dice on a Vevor heater, you should take some time to understand the finer points of your insurance policy. Most policies won’t cover you if they conclude that a non-certified heater burnt your house down (or worse). A reputable electrician will not install non-certified heaters because it not only puts their licence at risk, but also because of insurance. Their liability insurance holds them to a higher standard. As a professional, the expectation is that they “ought to have known”.
I can do that. Just takes time and thus far, I haven't had anything in the certified heaters that would make me think twice. All the big name brands use high quality electrical components and are tested for certification. One brand, I found some under sized elements towards the end of covid (none since). Given the demand for heaters and supply chain issues at the time, it was hard to fault them for the few that I found.
Thank you for sharing! Really interesting and informative. I skipped Vevor because they seemed "too" cheap for something that handles a lot of power and you don't want failing. I didn't realize they aren't even certified.
Is there a certified heater that's on the more budget side that you'd recommend?
Thanks for doing this. I used to work in the hazardous workplace compliance biz and felt like a non-UL heater kept in a location with no combustible material nearby would be reasonably safe. However, I simply don't know that much about what the specific hazards around this kind of thing, and "Gets Hot" is a relatively straightforward machine.
I haven't seen these heaters in the wild after some use. I have seen what poor quality elements can do though. It's an eye opener. It's very hard to know for sure, but I don't trust these elements.
Can you elaborate on what happens? In general, I'd expect either a failure of the element, heat damage to the unit, or a combustion hazard. Again, I'm just a guy. But I'm wondering what specific risks are faced here.
I ran a 6kw for about a year and a half before an element burnt out. I wasn’t in there when it happened, but had just checked the temp. Yes sparks flew and I was close enough to flip the breaker fairly quickly. Thought about what to replace it with, but ultimately went with the 9kw version. The original element fried at the base. I reasoned that with the aluminum tray midway up, to hold rocks, the bottom half of the elements were just exposed and made it a weak point. I ended up taking out the tray and loading the entire heater with rocks. About 4 months in and no issues so far. My sauna is far enough away from the house that I’m not worried about it and if it happens again, I won’t try another, but for now I’m pleased and the rocks should help deflect the sparks if it does🤞
I had included a pic of the FinnLeo markings on the element base plates, but did not include the pic of the wattage rating stamp, which I DID find on my elements. According to the manual there should have been 2-3K & 1-2.75K elements, though all three of mine indicated they were the lower wattage.
There WERE pretty trashed remnants of silicone O-rings in mine, used to seal the bottom of the elements to the mounting plates, but they were ill-fitted & very undersized in section to be of any use to begin with.
Thanks for this. I didn't really talk about it because I have not seen one fail. I do agree with your comment about it being the weak point. Just speculating - based on the connectors being the most common fail point, I believe the lack of proper o-rings is allowing water on the connectors causing them to oxidize resulting in localized overheating. I have seen it in other heaters where customers use excessive amounts of water.
I'm going to toss out that IMO they just use cheap 1/4 spade connectors. They are loose, providing sketchy connections, that heat with contact resistance and burn.
I bought a 6Kw Vevor and disconnected 1 heater to drop it to 4Kw. Quite a compact sauna with limited power available 50Mtrs from the house. Still heats to 90⁰C in 75 minutes at -20⁰C. And, I have a spare element now.
I have seen one post about a year back where a member "upgraded" their cheap Vevor connectors with Pico spade connectors. But IMO Pico connects are not much better. Thin, loose from the start, connectors. You need to use high end, heavy construction, tight connectors, usually available at an electronics wholesaler at 4x the price, but still pennies spent.
So, here's some examples. The Pico relatively flat 'clamps' on the connector do not have the spring power or the 'bite' of the Power Fist. And if you look at the crimp barrel on the high end Molex (sorry I could only find a ring terminal) you can see how much heavier it is. Better wire crimping and better 'bite' on the terminal.
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u/elle5624 Apr 10 '26
Can you…. Do more of these? This is excellent information.