Gas vs Electric Water Heater: How to Choose
Compare gas and electric water heaters on running cost, efficiency, recovery and install — and see which one leads for the priority that matters most in your home.
1 Enter your numbers
Gas usually wins on running cost and recovery; electric wins on install simplicity and, as a heat pump, on efficiency — your local rates decide. For your priority, Gas leads.
Gas and electric heat the same water; where they differ is running cost, recovery and install. Gas usually costs less to run where natural gas is cheap and recovers fast — a strong burner reheats a tank quickly, so you can get away with less storage. Electric wins on install simplicity (a dedicated circuit, no venting or gas line) and on unit price, but a resistance element is slow and the running cost is higher — unless you go electric as a heat pump, which flips efficiency in electric’s favor.
Because the answer rides on local energy prices, treat any “gas is cheaper” rule of thumb as a starting point and put your real $/kWh and $/therm through the operating-cost calculator before committing.
Formula
A weighted comparison, not a single number. The tool returns the leader for your priority:
- Lowest running cost → Gas where gas is cheap (a lower cost per delivered BTU at typical rates).
- Simplest installation → Electric (no venting or gas line — just a circuit).
- Best efficiency → Electric as a heat pump (UEF ~3.5 beats any combustion unit).
Delivered heat is the same either way (BTU = gallons × 8.33 × ΔT); the fuel and UEF set the cost. Compare dollars on the same heat with the energy-cost-by-fuel tool.
Worked example
Scenario: a home with cheap natural gas and a big morning hot-water peak. Priority = lowest running cost. The tool returns Gas: at a labeled UEF around 0.62 and typical gas prices it runs cheaper per year than a resistance electric tank (~0.92 UEF) and recovers fast enough to keep up. Change the priority to best efficiency and the answer becomes Electric (heat pump) — a UEF near 3.5 uses about a third of the electricity of a plain element, the biggest efficiency lever on the board.
What to check before you choose
Prices are local. The running-cost winner hinges on your $/kWh and $/therm — run the operating-cost tool with the numbers off your own bills, not a national average.
Recovery vs storage. Gas recovers faster, so a smaller gas tank can match a larger electric one on First-Hour Rating; electric resistance is slow, so electric tanks lean on more storage.
Install reality. No gas line? Adding one (or upsizing it) is real money and a licensed job. A heat pump needs warm space and clearance. Factor the install, not just the box.
Reference table
| Factor | Gas storage tank | Electric storage tank |
|---|---|---|
| Typical UEF (labeled) | ~0.62 | ~0.92 |
| Running cost | Usually lower where gas is cheap | Higher on resistance; lowest as a heat pump |
| Recovery | Fast — a strong burner reheats quickly | Slower — a 4,500 W element takes longer |
| Install | Needs venting and a gas line | Simpler — a dedicated circuit, no venting |
| Typical lifespan | 8–12 years | 10–15 years |
UEF and lifespan are labeled planning typicals — your local $/kWh and $/therm decide the real running cost. Confirm on the EnergyGuide label.