What it delivers
The ThermoMate ET240 24 kW Electric Tankless Water Heater is a whole-house electric tankless rated at 24 kW on 240 volts. Its listing gives a maximum flow of 5.8 GPM.
Flow depends on how cold the incoming water is. Our estimate from its input: 3.6 GPM at a 45°F rise, falling to 2.3 GPM at 70°F, which is 1 shower at 2 GPM on a cold-climate winter day. Try your own inlet temperature.
At 240 volts 24 kW is about 100 amps. Whether your panel can carry it alongside heating and cooking loads is an electrician's call.
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: features: Overheat Protection; model: ET240.
The listing gives dimensions of 13.11 in (W) x 17.13 in (H).
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
- 24 kW
- Up to 5.8 GPM
- No venting or gas line
Trade-offs
- Draws about 100 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 | ET240 | Retailer |
|---|---|---|
| Dimensions (seller) | 13.11"W x 17.13"H | Retailer |
| Features (seller) | Overheat Protection | Retailer |
| Max flow (maker) | 5.8 | Retailer |
| Power | 24 | Retailer |
| Voltage | 240 V | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- WINTEMP WM18V 18 kW Electric Tankless Water Heater
- WINTEMP YQ-WN27K 27 kW Electric Tankless Water Heater
- Ranein RE27K 27 kW Electric Tankless Water Heater
- VancEpic RE27K 27 kW Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every ThermoMate 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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