Electric vs Gas Pool Heater: Operating Cost Comparison

Electric heat pump pool heaters have a COP of 5–7, delivering 5–7 BTU of heat per BTU of electricity consumed. Gas heaters operate at ~80–85% efficiency. At national average rates, heat pump pool heaters typically cost 30–60% less per month to operate, though they heat the pool more slowly.

A gas heater can raise a 20,000-gallon pool by 10°F in 5–8 hours. An electric heat pump takes 24–72 hours for the same temperature rise. Heat pumps are better for maintaining temperature; gas is better for quick warm-up after a cold night. Many pool owners use gas for rapid warm-up and a heat pump for ongoing maintenance.

A common rule is 50,000 BTU per 10,000 gallons of pool water in moderate climates, or 100,000 BTU per 10,000 gallons in cooler climates. Manufacturers typically list required BTU capacity by pool size and climate zone. Undersizing a heat pump significantly reduces efficiency.

Most electric pool heat pumps require ambient air temperatures above 45–50°F (7–10°C) to operate efficiently. Below 45°F, efficiency drops sharply and units may switch to electric resistance backup. This makes them ideal for the spring-fall shoulder seasons but less effective in very cold weather.

Electric heat pump pool heaters typically last 10–15 years with proper maintenance. Gas pool heaters last 7–12 years on average, with heat exchanger corrosion often limiting their lifespan. Both benefit from annual inspection, winterization, and keeping pool chemistry balanced to prevent corrosion.

Rebates for pool heaters vary by utility. Some utilities (notably in Florida, Arizona, and California) offer $100–$500 rebates for switching to an electric heat pump pool heater. There are no federal IRA credits specifically for pool heaters. Check your utility's website or DSIRE.org for local incentives.