Whole-house electric tankless · Orbek

Orbek ET018 18 kW Electric Tankless Water Heater

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

18 kW240 V~75 A2 x 40A breakers~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.
Power
18 kW
Voltage
240 V
Breakers (maker)
2 x 40A breakers
Connections
3/4" npt
Material
Housing material is iron
Dimensions (seller)
3.9"W x 17"H
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What it delivers

The Orbek ET018 18 kW Electric Tankless Water Heater is a whole-house electric tankless rated at 18 kW on 240 volts.

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. The maker calls for 2 x 40A breakers. A licensed electrician confirms the panel, the service and the wire before it goes in.

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

Also on the listing: connections: 3/4" npt; material: Housing material is iron; model: ET018.

The listing gives dimensions of 3.9 in (W) x 17 in (H) and a weight of 18.3 lb.

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
  • 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 numberET018Retailer
Dimensions (seller)3.9"W x 17"HRetailer
Power18 kWRetailer
Voltage240 VRetailer
Product weight18.3 lbRetailer
MaterialHousing material is ironRetailer
Breakers (maker)2 x 40A breakersRetailer
Connections3/4" nptRetailer

Rival units at this flow

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Full electric tankless water heaters spec grid · Every Orbek unit in the catalog

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

What breakers does the Orbek ET018 18 kW Electric Tankless Water Heater need?
About 75 amps at 240 volts (18 kW ÷ 240 V). The maker calls for 2 x 40A breakers. Panel capacity, breakers and wire are confirmed by a licensed electrician from the manual.
How much hot water does the Orbek ET018 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.