Whole-house electric tankless · ECOAPTUNIT

ECOAPTUNIT XY-D08 18 kW Electric Tankless Water Heater

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

18 kW240 V~75 A4.4 GPM max~1.8 GPM at 70°F rise

Updated October 2026

The short answer

A practical 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)
4.4 GPM
Power
18 kW
Voltage
240 V
Connections
1/2" npt
Connectivity
leak detection
Dimensions (seller)
11.6"W x 17.7"H
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What it delivers

The ECOAPTUNIT XY-D08 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 4.4 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. Try your own inlet temperature.

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: connections: 1/2" npt; connectivity: leak detection; material: Acrylonitrile Butadiene Styrene, Glass, Stainless Steel; model: XY-D08.

The listing gives dimensions of 11.6 in (W) x 17.7 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

  • 18 kW
  • Up to 4.4 GPM
  • No venting or gas line

Trade-offs

  • Draws about 75 A
  • Weak at a large winter rise
  • 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 numberXY-D08Retailer
Dimensions (seller)11.6"W x 17.7"HRetailer
Features (seller)Energy Efficient Design, Advanced Temperature Control, Durable & Long-Lasting BuildRetailer
Power18 kWRetailer
Voltage240 VRetailer
Max flow (maker)4.4 GPMRetailer
MaterialAcrylonitrile Butadiene Styrene, Glass, Stainless SteelRetailer
Connections1/2" nptRetailer
Connectivityleak detectionRetailer

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Final verdict

A practical 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 ECOAPTUNIT XY-D08 18 kW Electric Tankless Water Heater draw?
About 75 amps at 240 volts (18 kW ÷ 240 V). Panel capacity, breakers and wire are confirmed by a licensed electrician from the manual.
How much hot water does the ECOAPTUNIT XY-D08 18 kW 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.