Best Ecosmart Tankless Water Heaters


Model Introduction

Ecosmart is an odd duck. I always say every brand (for any type of product) has a theme. Ecosmart has two: being very efficient, very powerful electric tankless water heaters, and their prices being very odd compared for what you get.

Full disclosure- I’m a bit predisposed to like this brand since every time I take a nice, hot shower I have the ECO 27 to thank, but that’s not really a bad thing. It just means I can go a bit more in depth when it comes to this one and give you my personal experiences with how this brand functions and whether they live up to the hype.

Some context before we go much further: EcoSmart only really makes one line of products available on Amazon (the ECO series). As these are their best products, this is only to be expected, but it also means this article is going to be a little different.

I’m going to give my primary recommendation up front, talk about a single outlier (primarily useful for RVs), and then break down the benefits and merits of the rest of the ECO series besides our winner (the ECO 36).


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Ecosmart ECO 36

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Ecosmart ECO 36 (View on

The biggest version of EcoSmart’s flagship series.

The ECO 36 is the most powerful tankless water heater Ecosmart makes. It has a pretty solid array of basic statistics: 99.8% efficient electric heater, close to 9 GPM in very warm climates, and easily adjustable temperature.

The main reason it’s the best is that it’s one of the best cold weather tankless water heaters on the market. It still gets an impressive 3.6 GPM with groundwater as cold as 37 degrees and a whopping 68-degree rise in temperature.

This is due to the massive efficiency of electric tankless water heaters. Since they don’t lose much of their heat in any weather (unlike propane or natural gas heaters) they can keep chugging at temperatures only the highest end propane or natural gas heaters can achieve.

As I said, I’m a bit inclined to like this series of tankless water heaters because it’s what I use (technically I use the ECO 27, one step down from this heater, but everything is fairly similar). Still, I wouldn’t throw them a mention (much less put one at the top of my list for this brand) if I didn’t think they were legitimately good.

Electric water heaters have a few downsides over propane or natural gas ones (they are naturally less suited to commercial applications, for instance), but I feel those downsides are almost completely removed in a residential setting.

There is, however, one I feel is worth mentioning: a relatively high minimum flow rate (.3 GPM). This isn’t normally an issue, but if you’re having problems with your water flow I can personally vouch that this series will give you some issues. To an extent this is true for ANY tankless water heater, mind, but the higher the minimum flow the biggest impact it has.

If your water flow is restrained by, hypothetically, the pump to your well being too weak you’re going to run into trouble getting the heater to even kick on (what little water you have will stay ice cold).

This isn’t likely to ever come up if you’re on city water, but if you run off a well like I do it’s a consideration to keep in mind when some brands have minimum GPM under .2.

Ecosmart POU 6 Point of Use Electric Tankless Water Heater (View on

Really good, as far as PoU models go.

While I’d absolutely steer clear in colder climates (it only gets .5 GPM if it has to raise the temperature 70+ degrees), for warmer weather use in something like an RV, food truck, bar, that kind of thing it works excellently.

It’s able to get 1.5 GPM at a 25 degree rise (perfectly sufficient if you’re in, say, Florida where the groundwater is 75+ degrees) pulling 220v of power (that means you need to be careful with an RV, as some plugins don’t let you draw that much at some RV parks).

Like all EcoSmart models it’s 99.8% efficient, so you don’t have to worry about a lot of power going to waste.

This model isn’t for everyone, but for what you get I feel the price is fair. Under $350 isn’t a bad deal for something you’ll be using regularly in a business or somewhere it’s hard to find a proper working tankless water heater (the market is very slim for RV tankless water heaters).

Series Breakdown

While the ECO 36 is the best overall, the others have merits of their own (all are located at this same link).

Bear with me for a second, this one is going to get pretty long. If you want the short and sweet: the ECO 27 is in many ways the best model if the ECO 36 is overkill for your needs, and similar cases can be made for most of the others.

The ECO series has six total models: the ECO 8, the ECO 11, the ECO 18, the ECO 24, the ECO 27, and the ECO 36.

We’ve already talked about the merits of the ECO 36: it is the most powerful and widely useful in varied climates of the series. However, it could be considered overkill in many cases. Extra power over what you need is completely wasted in any tankless water heater.

For example, if you only have one bathroom and a kitchen (two sinks and a shower, plus a dishwasher and washing machine), the MAXIMUM GPM you could ever conceivably need is 9 GPM (enough to run all five simultaneously), which is what the ECO 36 provides.

Realistically though, you’re only ever going to be running the shower plus maybe the dishwasher and washing machine at the same time. Your practical limit is therefore only 4 GPM. Anything above 4 GPM is just a waste…there’s no reason for you to be running everything at the same time, and that figure could be trimmed further to only 2.5 GPM just by staggering your usage.

ECO 27 (View on

Using a personal anecdote here, as I use the ECO 27. I have never had any issues with running out of hot water saved the aforementioned issue with my well (where my faucet flow was too low to actually ACTIVATE the tankless water heater). I live in a very warm climate, where the ECO 27 gets roughly 6 GPM on average.

Now, I have two bathrooms and a kitchen in this home. That’s two showers, two sinks, a dishwasher, and a washing machine. Theoretically that means I (or, I and my housemates in any case) could conceivably require close to 12 GPM, but realistically we only ever use a maximum of that 6 GPM (somebody is taking a shower while the dishwasher runs and somebody needs to wash their hands in the sink or something).

Buying the ECO 36 would have been overkill, and a waste of money (since the ECO 27 costs a little under $450. So, FOR ME (and anybody else with a similar set-up; 3 bed plus 2 bath house with three people in it), the ECO 27 is the best option, no matter that the ECO 36 is more powerful.

ECO 24 (View on

The Ecosmart ECO series suffers from awkward pricing in many cases. Certainly buying certain ones is overkill, but that’s only an issue if there’s a big pricing difference ($100 or more).

Many of the ECO series models are, however, the same price or negligibly cheaper. In my opinion this makes the ECO 24 and ECO 18 (below) quite undesirable, as they have lesser performance (an average of 5 GPM) for the same price.

You lose nothing by simply buying the ECO 27 instead in this case.

ECO 18 (View on

It hits 4.4 GPM in this climate, making it suitable for two people, only one of whom needs to shower at the same time (or in colder climates where it only hits around 2.6 GPM, the one bedroom one bath apartment).

Mind you, you only save about $50 over the ECO 27 (instead of the over $100 between the 27 and 36), so it may be worth it to buy up in this case as well. Some tankless water heaters, as mentioned, exist in a strange middle ground where they don’t necessarily perform well enough for their savings.

In my opinion this makes the ECO 18 in many ways the worst of the bunch, as while it’s staunchly middle of the road in performance it doesn’t fill any given niche as well as any of the others. At least it is a bit cheaper than the ECO 24…though is significantly worse in performance.

ECO 11 (View on

This is a great model or someone with a very small apartment that lives alone, in a warm climate. It can hit about 3 GPM if the water temperature is above 70 degrees already. Pricing wise it’s a much more reasonable drop for its drop in performance, running a bit under $250 and filling a wholly different niche than some of the other, more powerful (but unfavorably priced) models above.

ECO 8 (View on

Suffers the same issues as the 18 and 24 in comparison to the 27 in regards to the 11. It has severely reduced performance (only around 2 GPM at the extreme maximum) and is only about $10 cheaper. Useful as a point of use model, I suppose, but is also barely cheaper than the PoU 6 with not much better performance, and isn’t particularly compatible with RVs. Hard pass on this one.


The ECO 36, 27, and 11 are the standouts from this brand. All are good for different types of people and situations while being significantly different enough in price to not have you asking yourself:

“Why don’t I just buy the bigger one, just in case?”

The ECO 18, 24, and 8 models aren’t bad, per se, but suffer from very strange pricing. In every regard they are either identical or inferior to the ones they should be most easily compared to, but are priced to be nearly identical or negligibly cheaper than their more powerful counterparts.

All in all Ecosmart is a very strange brand with a number of great models, but unappealing pricing scheme.