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Written from the listing and 10 buyer reviews, not from our own use · How we rate
On paper, the EcoSmart ECOS 18 (18 kW 240V) gets the important things right: 18 kW at 240 V and an element that only draws what it needs. A good match for a southern house with warm tap water and no gas line, with 10 buyer reviews averaging 3.3/5.
| Brand | EcoSmart |
|---|---|
| Category | Electric tankless water heaters |
| Fuel | Electric |
| Stated heating power | 18 kW |
| Stated voltage | 240 V |
| Total current | 75 A |
| Buyer reviews | 10 · 3.3/5 |
| ASIN | B0BXZF8FVH |
Full listing title: EcoSmart ECOS 18 Tankless Electric Water Heater, 18 Kw at 240 Volts, 75 Amps with Patented Self Modulating Technology
| Fuel | ElectricFull listing title |
|---|---|
| Stated heating power | 18 KwFull listing title |
| Stated voltage | 240 VoltsFull listing title |
Rated from the listing's specs, no buyer reviews yet
What it's made for: a southern house with warm tap water and no gas line.
Two electric tankless heaters of about the same power, closest to it on our rating, each with a dated price.
The heating power the listing states. At 240 V it draws about 75 A. Before you think about showers, your electrician has to say yes to that number at the panel in the garage.
What it has going for it
Self-modulating. It draws only the power the flow and the setpoint need, instead of slamming every element on. Steadier temperature, and no wasted amps on a summer afternoon.
Warm tap water: where it comes in around 62 °F (much of the South), 18 kW gives about 2.9 GPM of 105 °F water on our calculator's maths. That's one 2 GPM shower at a time.
A cold January: where it comes in at 42 °F, it's about 1.9 GPM, less than one 2 GPM shower. Up north, that's the figure to size against, and it's why the honest answer is sometimes a second unit or gas.
What the EcoSmart ECOS 18 (18 kW 240V) listing names:
The installation manual has the last word on breakers and wire size; show it to your electrician before you order.
We have no recent price on file for this listing, so we don't print an old one.
The electrician comes on top: new double-pole breakers, heavy wire and, in some houses, a panel upgrade.
The button opens the exact listing (ASIN B0BXZF8FVH), where today's price, stock and seller apply.
Colder tap water where you live? The WINTEMP WN-36kW Electric, 240V (8.1/10) is rated 36 kW.
Only one sink far from the heater? The ThermoMate 14 kW Electric, 240V (7.9/10) is a 14 kW point-of-use unit.
Our take
What we'd buy the EcoSmart ECOS 18 (18 kW 240V) for is 18 kW at 240 V, with an element that only draws what it needs as a bonus. Only 10 buyers have rated it so far (3.3/5), so treat the score as an early read. Where it falls short: their 3.3/5 average sits under the 4.3 of our ranked picks. We'd pick it if you live somewhere the tap water never gets icy; otherwise, put it next to the WINTEMP WM-36kW Plus Electric (240V) first.
New breakers, the unit on the wall next to the old tank's spot, water in and out. An electrician does the panel side.
Hot in a few seconds once the water in the pipes has passed, and the power steps up and down with the flow (self-modulating, per the listing). Set it, then leave it.
With 42 °F water coming in, 18 kW gives about 1.9 GPM at 105 °F on our calculator's maths. Low-flow shower heads stretch that further.
Clean the inlet screen and flush out scale on hard water. Our flushing and descaling guide has the routine.
Buyers give it 3.3/5, a mixed record, below our ranked picks' 4.3 average. Only 10 reviews so far, and our formula damps averages built on fewer than 50.
Before the EcoSmart ECOS 18 (18 kW 240V) ships, check your panel: it draws 75 A, so an electrician should look at the panel first.
Take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for.
On our calculator's maths, 18 kW gives about 1.9 GPM with 42 °F winter water and 2.9 GPM with 62 °F water. Our flow-rate calculator does it for your region.
Hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote.
Hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.
How the EcoSmart ECOS 18 (18 kW 240V) stacks up against the closest alternative, the WINTEMP WM-36kW Plus Electric (240V).
| Criterion | EcoSmart ECOS 18, 18 kW 240V | WINTEMP WM-36kW Plus Electric, 240V |
|---|---|---|
| Our rating | 7.5/10 | 7.6/10 |
| Heating power | 18 kW | 36 kW |
| Max flow | Not stated | 8.7 GPM |
| Warranty | Not stated | 2 years |
| Buyer reviews | 10 · 3.3/5 | 60 · 4.3/5 |
Pick the WINTEMP WM-36kW Plus Electric (240V) if you want our higher-rated option (7.6/10), with more power (36 kW) and more stated flow (8.7 GPM).
We rate it 7.5/10 (very good). The rating comes from its documented listing alone, as no customer-review record is captured yet.
The listing states a heating power of 18 kW on 240 V. The headline flow is a mild-weather number: with cold winter water coming in, the same unit gives you less. Read the maker's flow chart at your winter rise, or let our flow-rate calculator do the sums.
The listing states 240 V and 18 kW. At 240 V, that is roughly 75 A. A licensed electrician checks the panel, the breakers and the wiring before it goes on the wall.
Its listing states 18 kW of heating power and self-modulating power. These are the seller's figures, not our measurements: how steady the temperature is in your shower and how it copes with your winter water can't be read from a listing.
Your panel: take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for. Your winter flow: on our calculator's maths, 18 kW gives about 1.9 GPM with 42 °F winter water and 2.9 GPM with 62 °F water. Our flow-rate calculator does it for your region. The install: hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote. Scale: hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.
We link to the exact listing on Amazon, where today's price, stock and seller apply. It is an affiliate link, and it has no effect on the rating.
No, we haven't used it ourselves. Everything on this page comes from its listing and 10 buyer reviews, read line by line and weighed with our published formula.