What it delivers
The WINTEMP WM18V 18 kW Electric Tankless Water Heater is a whole-house electric tankless rated at 18 kW on 240 volts. Its listing gives a maximum flow of 4.3 GPM.
At a 45°F rise (mild inlet water to a 120°F set point) it holds about 2.7 GPM, 1 shower at 2 GPM; in winter, at a 70°F rise, about 1.8 GPM, less than one 2 GPM shower. Check your house in the planner.
At 240 volts 18 kW is about 75 amps (the listing states 75 A). The maker calls for 2 × 40 Amp double-pole breakers. 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.
From the listing: connections: 3/4" npt; connectivity: WiFi; material: Metal; model: WM18V; warranty: 2 Year.
The listing gives dimensions of 13 in (W) x 15.9 in (H) and a weight of 19.5 lb.
Warranty, per the listing: 2 Year.
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 4.3 GPM
- No venting or gas line
- Breakers stated by the maker
Trade-offs
- Draws about 75 A
- Flow drops with cold inlet water
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 | WM18V | Retailer |
|---|---|---|
| Dimensions (seller) | 13"W x 15.9"H | Retailer |
| Features (seller) | LED Display, Self-Modulating, Smart Home ＆ Tuya Smart Compatible, Temperature Lock, WiFi | Retailer |
| Power | 18 kW | Retailer |
| Voltage | 240 V | Retailer |
| Max flow (maker) | 4.3 GPM | Retailer |
| Product weight | 19.5 lb | Retailer |
| Warranty | 2 Year | Retailer |
| Material | Metal | Retailer |
| Amps (maker) | 75 A | Retailer |
| Breakers (maker) | 2 × 40 Amp double-pole breakers | Retailer |
| Connections | 3/4" npt | Retailer |
| Connectivity | WiFi | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- 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
- Westinghouse ET018KA1G 18 kW Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every WINTEMP unit in the catalog
Final verdict
A solid whole-house electric tankless for one shower at a time in mild climates.
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