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CostORun

Electric radiator vs Tankless water heater: which costs more to run? (2026)

Estimates use U.S. average $0.180 $/kWh, typical wattage, and typical hours/day from our catalog. Adjust on each appliance page.

Electric radiator

Typical watts
1500 W
Hours/day
6
Monthly est.
$48.54
kWh/mo
270.0

Tankless water heater

Typical watts
18000 W
Hours/day
1
Monthly est.
$97.08
kWh/mo
540.0

Tankless water heater is estimated to cost more per month at typical use.