Heat Pump vs Gas Water Heater: Annual Cost Comparison

A heat pump water heater almost always costs less to run per year than a gas water heater, because it moves heat instead of burning fuel to create it — but the upfront switching cost (new electrical circuit, possibly capping a gas line) is real, and your specific electricity and gas rates decide how fast that running-cost gap pays back the conversion.

Illustration of a heat pump water heater standing next to a traditional gas storage tank water heater.

Likely Causes, Ranked

Fuel cost per unit of heat delivered
A heat pump typically delivers 3–4x more heat energy per unit of electricity consumed than resistance heating — the comparison against gas depends on your local $/therm vs $/kWh.
Conversion cost
New electrical circuit, possible gas line capping, and permit costs all factor into the real payback period, not just the sticker price of the unit.

FAQ

Does switching from gas to heat pump always save money?

Not always, and not immediately — it depends on your specific utility rates and the conversion cost. Run your own numbers with local rates rather than relying on a national average.

Written by HotWater Decoded — water heater repair specialists. Technically reviewed by a licensed technician on our team.

Sources

DOE water heater efficiency comparisons and Rewiring America installed-cost data, applied against representative utility rate ranges