Electric Tank Water Heater, 8.0 Gallon Point of Use Instant Small Hot Water Heater 120V 1440W, Wall or Floor Mounted, Plug-in to Use, UL Listed ES800

I am in a house I just recently bought. The gas company is super unfriendly, their "inspector," is not a nice person and after clearing the house with the gas on a few months ago now says all the gas lines must be replaced? They're not even old. So, yeah, bye bullying GAS Company! I yanked out the gas stove and put it on Craigslist the next day, lovely electric cooktop now installed. We have options, today. Anyway, I researched and researched, and found this portable electric HWH that consumes low amps and is 110v! I have to admit, the box arrived and I was intimidated. I got online and started looking for "all the stuff," I'd need to install it, lines, fittings, even tools. Imagine my delight when I discovered I needed nothing other than what was already there in the house and some teflon tape I already had. Even installing the pressure relief valve (they provided it, thanks so much) was a breeze. Start to stop, it was making water hot less than 30 minutes after I opened the box. I'm using this right now in a shower. I have to spray, suds, rinse, but it SO beats ice cold showers. My plan will be to use this unit eventually in my outdoor bathhouse, but today, it's saving my life by providing me with a hot shower. So, so happy I bought this. Update 5/12/2025 - Still working great, used it this morning!

Works great! Heats quickly

Installed under the kitchen sink so we get hot water fast. I like the size and ease of installation, but these units usually only last a few years. Just know you'll need to replace every few years.

installed this ThermoMate mini tank water heater under the sink, and it’s been really handy. Instead of waiting for hot water to travel from the main heater, it delivers warm water almost instantly, which is great for washing hands and dishes. The unit is compact, fairly quiet, and the installation was pretty straightforward with basic tools. It heats up quickly and keeps the temperature steady once it’s set. I also like that it can sit on the floor or be mounted to the wall, so there’s some flexibility depending on your space. The only downside is that the tank is small (as expected), so if you run the water continuously, it will run out after a short while and needs time to reheat. Not a big deal for point-of-use, but it’s worth knowing. The manual could also be a bit clearer. Overall, this is a solid mini water heater for sinks and small tasks. Not perfect, but it works well and makes everyday use much more convenient. I’d buy it again.

arrived on time very easy to install and instant hot water at our kitchen sink. Does take up some space under the sink

I selected his heater as a trial for kitchen sink upgrade due to its smaller size and price point. So far it’s doing just what it was intended to do. Nothing like having instant hot water 👍 How well it holds up only time will tell but I would not hesitate to recommend it at this point.

I originally published a glowing review of this unit two years ago, It's not so glowing now. After using this unit without incident for 2+ years, I was shocked to suddenly find it leaking, and spectacularly – the plumber’s tape seal around the relief valve had failed, and water was dripping from the kitchen (where the unit is installed) into the basement below. Had I not been home, this could have been a major disaster. The reason for the leak, as explained to me by my plumber, whom I called to fix this mess, is that the relief value is wrapped by default in a plumber’s tape that is unsuitable for higher temperatures, and thus this almost-disaster was only a matter of time. Upon pulling the value out, I discovered a major amount of black limescale buildup. This is a common problem is all water heaters, and a sacrificial anode rod is thus a key element in all such heaters. The manual for this unit does mention descaling and replacing the rod, but this service is a major deal, requiring the disassembly of the unit. I’m not qualified to do this, and the cost of having a plumber do such is much more than the cost of a new unit. So I must conclude that two years of life is the best that one can hope for here. Customer Service at ThermoMate sent me a new unit at no charge, and my thanks to them. However, two things: The expense of hiring a plumber to fix this problem was much higher than the cost of the unit itself, and they sent the old model, not the newer ES400B, which appears to be a better design, at least from the description, and, on Amazon, a lower price to boot. Gotta blow out the old, obsolete stock, I guess. So – yes, this unit works. I love not having to wait up to a minute to get hot water (the kitchen is apparently quite some distance from the house water heater, as the hot water flies), but the cost of this convenience is much higher than I expected when I originally purchased the product. Hence – a low rating. Buyer beware, although I cannot speak to the reliability of the newer model, which is, I’m sure, what most people will purchase at this point and going forward.

Works great

I purchased this for installation under my kitchen sink so that the dishwasher will always have hot water for washing in case the kids forget to run the tap for a half minute first before starting the load. I ordered and received the 120V 4.5KW version. You need to do your research before you buy this because it requires 10-gauge wiring and a 40-amp GFCI circuit breaker which is harder to find and more expensive than you think. I ended up doing two parallel runs of 12-gauge wire to a tandem (2x20A) breaker to get my 40 amps of current capacity. Operation is good but a little underwhelming. The product performs to spec, but 4.5 kW doesn't do a lot for flowing water. Here are some numbers I've observed: - our kitchen faucet flows at 0.9 gallons per minute, as reported by this product, with the hot tap open and the cold tap closed - if the tap hasn't been opened in a while, inlet water temperature is around 70 F, as reported by the unit - this unit doesn't draw any current from the mains until ~4 seconds after the hot tap is opened, and then it immediately jumps to drawing the fully-rated 36 amps - after the unit starts heating, the reported water temperature quickly climbs to about 101 F - about 20 seconds after opening the hot tap, the temperature indicated on the unit climbs quickly to the set point of 131 F, suggesting that hot water has reached the unit from the home's main hot water tank So my observation is that the unit itself can raise water's temperature by about 31 F or 17 C at a flow rate of 0.9 gallons per hour. In my experience, most kitchen faucets can flow hot water faster than this one, so you'd see a rise even less than this at faster flow rates. I checked the math with duck.ai and these numbers are very close to what is expected in my circumstance. My dishwasher just died, so I haven't had the opportunity to see what the water flow rate will be with the replacement when it arrives in a few days. Hopefully it draws water at less than 0.9 gallons per hour, or the inlet temperature will be less than the recommended minimum of 120 F, except in the rare case where the water entering the on-demand heater is already elevated to 90 F or more. Unless it just isn't an option, I strongly recommend that you consider buying the 240V 6KW version since it would require a lighter gauge wire, a smaller dual-pole breaker, and keeps up with heat demands better with anything more than minimal water flow.

I have on demand tankless water heater for whole house. It wastes a large amount of water before getting hot enough at kitchen sink. Tried the small 2 gallon electric hot water in the past but found the elements were constantly burning out. This little tank puts out ample heat for the few minutes that we require for washing dishes etc. It does struggle after a few minutes with its 120 volt heater and because our well water is very cold (8 degrees C ) but covers the time it takes the main on-demand water to reach the tap. 8 months so far and doing well.

I installed this tankless water heater at my cottage where I only go during week-ends. I wanted to have access to hot water on demand, but since we are there probably 50 days a year, a heater with a tank would mean empty it before every winter. I wanted something easy to install that is more affordable than a typical water heater. Or course, we don't rely on it to take baths or use a washing machine, that would be impossible, but it is perfect to be able to clean the dishes, or take quick showers without having to heat water on the wood stove like we used to. The fact that it runs on 120v simplified the install a lot in my case! Of course this water heater has it's limits, but for occasionnal use in a tiny house, a 3 seasons cottage or even a garage , I think this is a very nice option to have!!

Easy to install once power had been routed to under sink. Heater just sits on bottom of cupboard as thin backing of cupboard was not conducive to mounting. Harly takes up any space at back of cupboard. Temperature setting is at max and water is sufficiently hot (too hot at times). Power cord is just 2 feet long, so consider proximity to outlet if outlet is being installed. It needed some adapters installed on the 1/2 inch males inlet/outlet to convert to 3/8 pressure fit which matched the faucet on the sink. No other plumbing required. This unit was selected as it supports a hot water feed from the main water heater. It sits in a small tray to capture any overflow should that occur.

I purchased a 2.5 and 6 gallon for use on a boat powered by inverter and solar. The 2.5 takes about 6 minutes to heat, and so you can get hot sink water for about 120 watts, decent for this setup on a boat by turning it on only when needed. Proximity to the outlet reduces fresh water use, also important on a boat. This key flaw seems to be the heat gets diluted as the tank fills with fresh water during use, so in short order you get luke-warm water rather than hot. This is more noticeable in the 2.5 gallon than the 6, which is used for the shower. Still, the temperature does not seem constant during an average shower. Overall well designed and a fraction of the cost of a marine water heater, so overall a good rating and I would recommend these units for this purpose.