Home Heating Heroes
Your Guide to Home Heating and Cooling Systems
Electric tankless water heaters are in some ways my preferred type…but in others they’re very limited. The ratio of good to bad models is far more skewed towards the bad than propane or natural gas water heaters. There are many that are underpowered (either overall or just for the price) and it’s hard to sift the wheat from the chaff.
That’s what I’m here for today, to help trim down the overwhelming variety of bad options to a more manageable selection of good to great tankless water heaters for you to choose from.
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PROS
SPECS
EcoSmart ECO 27
PROS
Compact size
Endless hot water
Limited lifetime warranty
SPECS
Dimensions: 17 x 17 x 3.625 inches
Pipes fittings :3/4 inch NPT
Activation Flow: 0.3 GPM
Digital temperature control
Ecosmart ECO 36
PROS
Sleek and compact design
Digital temperature control
Copper and stainless components
SPECS
Dimensions: 17 x 19 x 3.8 inches
Voltage: 240 Volts
Wattage: 36000 watts
Ampere Capacity: 150 Amps
Eccotemp iE-11
PROS
Advanced temperature control
Rust and corrosion resistant
On-board Diagnostics
SPECS
Dimensions: 22" x 15" x 7"
Voltage: 240 volts
Flow Rate: 1.8 GPM
ETL Certified
Eemax HA008240
PROS
90% space saving tank
Can put your heater anywhere
Scald prevention
SPECS
Dimensions: 18 x 14 x 4.5 inches
Weight: 7.04 lbs
Voltage: 240V
Flow Rate: 3GPM
Atmor AT-910-27TP
PROS
Digital temperature control
Stainless steel interior
Easy Operation
SPECS
Dimensions: 17.38 x 5.25 x 13.38 inches
Weight: 17 lbs
Voltage: 240 Volts
Wattage: 27kW
The model I use at home, and a good alternative to the ECO 36.
The thing with tankless water heaters is that there is such a thing as “too much”. If you don’t need 9 GPM, then buying a more expensive (but more powerful) model is completely a waste of money.
Personally I don’t use all that much water at once (in hindsight 6 GPM was actually too much for my needs as well; I just got the maximum I could possibly use) and neither do a lot of people. At most, many people will use two showers at the same time or some equivalent (like a shower plus the dishwasher and washing machine), so 6 GPM is more than enough.
The ECO 27 is in no way BETTER than the ECO 36, but if you don’t need the bonus 2 GPM saving an extra $100 or so is never a bad idea. This sot of applies to the rest of Ecosmart’s ECO series as well, though the pricing is quite odd on a lot of them to the point I can’t really recommend most of them over the competition.
Ecosmart’s top of the line is also the best on the market.
It’s almost scary how much better than the competition the ECO 36 is. In every regard it outclasses every other electric water heater I could find: and does it cheaper.
I’d be wary of trusting that information blind (as the saying goes: if it sounds too good to be true, it usually is) but my first hand experience with Ecosmart’s Eco series (the ECO 27 is the model I’ve used the longest) tells me it’s no bluff.
At close to 9 GPM in warm climates (and a still solid 3.6 GPM in places with groundwater temperatures as low as 37 degrees and a 68 degree rise) it puts a lot of tankless water heaters to shame. Add in that it’s under $600 and you have the making for a true winner.
My only complaint is its relatively low minimum GPM to function (.3 GPM), which is outperformed by almost every propane or natural gas tankless water heater out there, but compared to its competition in the electric realm even that is significantly higher (some on this list run as high as .5 GPM minimum activation, meaning they might struggle with hot washes in a low flow washing machine).
You can’t go wrong choosing this one.
I’ll get right down to brass tacks: this tankless water heater’s only real claim to fame is that it’s cheap. Like, really cheap.
It doesn’t perform POORLY, per se, but it is relatively unimpressive even for a point of use heater. It has 1.8 GPM at a 40 degree rise (making it only suitable for relatively warm climates, and really only for a sink, not a shower) and a few minor standard features like corrosion resistance and digital temperature adjustment.
No, its main draw is that it costs well under $200 (a bit closer to $150, actually) and can do the job better than anything else in that particular price range (where it admittedly has very little competition).
“Small, but mighty” isn’t quite an accurate expression, but it is perhaps better than anything in that price range has a right to be, which is enough for me to give it a shout out.
An okay point of use model.
I’d consider this pretty much the bare average of what you can expect from an electric point of use model: 3 GPM, 240 volt power draw, and under $300. Not particularly impressive, but for the price, it’s pretty good. Good enough to nab a spot on the list, but I’ll admit this is the iffiest option on the list by far.
It mostly makes it here by being in a favorable price range. It’s a little cheaper than others which either perform better or have a bunch of fancy extras on top but lesser performance (like our below option) and having just enough power to run multiple things if need be (convenient for a small kitchen that just needs something to run a single sink and dishwasher, for example).
Good, reliable, and high performance.
I like this one. It hits a solid 4.6 GPM in warmer temperatures, making it entirely suitable for whole home use. It even still hits a decent 2.45 GPM in colder climates (groundwater 37 degrees).
For the price (around $400), it’s hard to call that a bad deal. While it’s little more than a point of use model in colder climates (and thus a bit pricy) it’s not all THAT bad, and if it weren’t for a few models only a bit more expensive (like the ECO series 27 and 36) so vastly outperforming it, it might be a bit closer to the top of my list.
As is it’s still a solid pick for the price if you live somewhere warm like I do, which is kind of the mantra you need to keep in mind for a tankless water heater cold climate use is a plus, but not to be expected.
Electric tankless water heaters, unfortunately, suffer from this a bit more, as their heat output is usually lower, and that deficiency is only partially offset by their greater efficiency (which isn’t THAT much greater than a condensing tankless water heater).
This tankless water heater is just cool.
I’ll admit, part of my reasoning for putting this on here is my enjoyment of how it works. Unlike most electric tankless water heaters which use heating coils (usually copper), this one uses crystals. On top of that, it heats your water with LASERS!
Well, sort of.
The crystals heat up and start emitting far infrared light, heating your water indirectly without ever touching it. Conceptually fun, and has some practical use as well: since the water never touches your heating element, there’s no chance for the water to corrode it, build up limescale or other mineral buildups, or anything like that.
This significantly cuts down on maintenance (both in frequency and effort required when you inevitably do need to service it) and allows it to work for far longer.
The only real downside to that unique function is that it’s slightly less efficient than some of its competition (a “mere” 98% energy efficient).
I wouldn’t put it on here JUST for that though, however, cool it is. It has a solid performance to back it up: 2.3 GPM at a 30-degree rise in temperature, making it perfect as a point of use model for warmer climates like the southern United States.
That output is entirely unsuitable for colder climates, but frankly so are most tankless water heaters of ANY stripe. Where it works it works well, and in a unique way, and it will only cost you around $350. Give it a look.
Only held back by the price.
In terms of raw performance, this is just about the best there is. An 8 GPM at a 30 degree rise, and even at a 90 degree rise (overkill even in the coldest climates) it gets a respectable 3 GPM. On its own that would make it great (and it is), but there are two main downsides that might make you think twice if 8 GPM is way more than you need (which, in many cases, it definitely is).
First is the minimum GPM to activate: an immense .77 GPM, over double the average I’d expect from any tankless water heater.
The other issue is the price: anywhere between $800 and over $900. You’re essentially paying an extra $200 to $300 for an extra 2 GPM over our winner, the Ecosmart ECO 36. Still, if you NEED that much power, you can’t go wrong with Stiebel Eltron, as they’re a reliable brand with high-quality products, and a solid warranty (7 years on leaks, three years on other failures).
The Ecosmart ECO 37 is the obvious winner here, but it has SOME competition in the Stiebel Eltron Tempra 36 (36 seems to be the magic number for good electric tankless water heaters…).
Other brands provide products that fill certain niches, but electric tankless water heaters are overwhelmingly Point of Use models more than anything else. That gives the type as a whole a big niche that propane and natural gas models don’t appreciably fill (there are few Point of Use models of that type at all, and most of those fall well behind the performance of any electric Point of Use tankless water heater).
If you are interested in other fuel types, check out our complete tankless water heater reviews. Also read our blog on how to install an electric water heater.