Whole-House Electric Tankless Water Heaters Ranked by Power

Listed when: An electric tankless water heater whose listing states 24 kW or more.
Sorted by: Power (highest first)
In the list: The top 8 of 33 products in our catalog that meet the rule.

#1 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise; maker calls for 4 dedicated double-pole 40A breakers.

#2 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise; maker calls for 4) × 40A double-pole (DP) circuit breakers.

#3 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise; maker calls for 4 × 40 Amp double-pole breakers.

#4 · Power: 36 kW

36 kW (about 150 A at 240 V), about 0.8 GPM at a 45°F rise.

#5 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise.

#6 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise.

#7 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise.

#8 · Power: 36 kW

36 kW (about 150 A at 240 V), about 5.5 GPM at a 45°F rise.

How to choose between them

A 27 kW unit draws about 112 amps at 240 volts and holds about 4.1 GPM at a 45°F rise; a 36 kW unit, 150 amps and 5.5 GPM.

Check the amps against your panel; a licensed electrician confirms it.

Rankings follow the rule and order stated above, using makers' published specifications and listed prices. How we research · Disclosure