What it delivers
The EcoSmart ECOS 18 Electric Tankless Water Heater is a whole-house electric tankless rated at 18 kW on 240 volts. Its listing gives a maximum flow of 4.4 GPM.
Flow depends on how cold the incoming water is. Our estimate from its input: 2.7 GPM at a 45°F rise, falling to 1.8 GPM at 70°F, which is less than one 2 GPM shower on a cold-climate winter day. Size it to your fixtures.
At 240 volts 18 kW is about 75 amps. A licensed electrician confirms the panel, the service and the wire before it goes in.
No flue, no gas line and a compact box on the wall; the trade-off is that a cold winter inlet cuts its flow sharply.
Also on the listing: material: Plastic; model: ECOS 18; warranty: 5 Year Limited.
The listing gives dimensions of 9.25 in (W) x 19 in (H) and a weight of 9.3 lb.
Warranty, per the listing: 5 Year Limited.
Right unit for this house?
Install it when
- One shower at a time in mild climates
- Homes with no gas service
Look at another unit when
- Panels without spare capacity
- More than 1 shower at once in cold winters
Strengths and trade-offs
Strengths
- 18 kW
- Up to 4.4 GPM
- No venting or gas line
Trade-offs
- Draws about 75 A
- Winter flow is much lower
- Breaker needs not stated
Install limits
- Figures are the maker's or seller's own. Flow at a rise is our estimate from the input; gas, venting and electrical work needs a licensed professional.
Rated performance
Every figure below comes from the source shown in brackets. Where the maker doesn't state something, we say so instead of estimating.
| Model number | ECOS 18 | Retailer |
|---|---|---|
| Dimensions (seller) | 9.25"W x 19"H | Retailer |
| Power | 18 kW | Retailer |
| Voltage | 240 V | Retailer |
| Max flow (maker) | 4.4 GPM | Retailer |
| Product weight | 9.3 lb | Retailer |
| Material | Plastic | Retailer |
| Warranty | 5 Year Limited | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- Westinghouse WET-24K-G 24 kW Electric Tankless Water Heater
- Westinghouse ET018CA0G 18 kW Electric Tankless Water Heater
- Atmor AT-36N-XTP 36 kW Electric Tankless Water Heater
- WINTEMP WN36 Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every EcoSmart unit in the catalog
Final verdict
A practical whole-house electric tankless for one shower at a time in mild climates.
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