Whole-house electric tankless · WINTEMP

WINTEMP WN18 Electric Tankless Water Heater

18 kW whole-house electric tankless, about 75 A at 240 V

18 kW240 V~75 A2 x 40 Amp DP breakers4.3 GPM max~1.8 GPM at 70°F rise

Updated October 2026

The short answer

A well-specified whole-house electric tankless for one shower at a time in mild climates.

Delivers
18 kW.
Watch for
Draws about 75 A.
Suits
One shower at a time in mild climates.
Max flow (maker)
4.3 GPM
Power
18 kW
Voltage
240 V
Amps (maker)
75 A
Breakers (maker)
2 x 40 Amp DP breakers
Connections
3/4" npt
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What it delivers

The WINTEMP WN18 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.

Expect about 1.8 GPM with cold winter water (a 70°F rise) and 2.7 GPM when the inlet is milder (45°F rise); that is less than one 2 GPM shower in January. 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 x 40 Amp DP breakers. Whether your panel can carry it alongside heating and cooking loads is an electrician's call.

Electric tankless units need no venting and no gas, and work best where inlet water stays mild, because every degree of rise costs flow.

Listed details: features: LED Display, Overheat Protection, Temperature Lock, Wifi Control; connections: 3/4" npt; connectivity: WiFi; material: Acrylonitrile Butadiene Styrene; model: WN18; warranty: 2 Year.

The listing gives dimensions of 11.1 in (W) x 19.2 in (H) and a weight of 12 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 numberWN18Retailer
Dimensions (seller)11.1"W x 19.2"HRetailer
Features (seller)LED Display, Overheat Protection, Temperature Lock, Wifi ControlRetailer
Power18 kWRetailer
Voltage240 VRetailer
Max flow (maker)4.3 GPMRetailer
Product weight12 lbRetailer
Warranty2 YearRetailer
MaterialAcrylonitrile Butadiene StyreneRetailer
Amps (maker)75 ARetailer
Breakers (maker)2 x 40 Amp DP breakersRetailer
Connections3/4" nptRetailer
ConnectivityWiFiRetailer

Rival units at this flow

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Final verdict

A well-specified whole-house electric tankless for one shower at a time in mild climates.

Buy this unit

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Prices change often; the button shows today's price.

Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure

Questions buyers ask

How many amps does the WINTEMP WN18 Electric Tankless Water Heater draw?
About 75 amps at 240 volts (18 kW ÷ 240 V). The maker calls for 2 x 40 Amp DP breakers. Panel capacity, breakers and wire are confirmed by a licensed electrician from the manual.
How much hot water does the WINTEMP WN18 Electric Tankless Water Heater deliver in winter?
About 1.8 GPM at a 70°F rise and 2.7 GPM at a 45°F rise, estimated from its power and capped at its stated maximum.