Answer
Mar 10, 2026 - 02:01 PM
The cost to run a 400,000 BTU pool heater depends on the type of fuel and local energy prices. For natural gas, running the heater for one hour typically uses about 4 therms (400,000 BTU ÷ 100,000 BTU/therm), so at $1.50 per therm, it would cost about $6 per hour. Costs for propane or electricity will differ, but propane is usually more expensive than natural gas.
