How Much Does It Cost to Run an Electric Water Heater in California? (2026)
A tank water heater is often the single largest electricity user in a home without electric heating. The element only runs a few hours a day, but at 4,000 watts or more those hours add up fast.
A typical electric water heater (4,000 W) costs $1.39 per hour, or about $125.06 per month at 3 hours a day in California. Expensive to run
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low 3,000 W | $1.04 | $4.17 | $125.06 | $1,522 |
| Typical 4,000 W | $1.39 | $4.17 | $125.06 | $1,522 |
| High 5,500 W | $1.91 | $4.17 | $125.06 | $1,522 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 3 h/day ≈ 4,380 kWh per year. A more powerful model does the same job faster, so it uses the same energy: the cost per hour changes from row to row, the cost per day does not.
One hour of an electric water heater (4.0 kWh) is the same electricity as
- 22km in an electric car
- 40hours of TV
- 89hours of a laptop
- 444hours of an LED bulb
In California, with electricity at 34.7¢ per kWh (source: EIA Table 5.6.A, 2026-06), a typical electric water heater costs $1.39 per hour and about $1,522 per year at 3 hours a day. That is about 89% more than the national average for the US ($66.02 per month), because electricity in California costs 34.7¢ per kWh against 18.3¢ nationally. Each $1.00 of electricity buys roughly 0.7 hours of use.
How to lower the cost of running an electric water heater
- Set the thermostat to 120 F (49 C). Factory settings are often 140 F.
- Insulate the tank and the first few feet of hot water pipe.
- Fix dripping hot taps. A slow drip can waste hundreds of litres of heated water a month.
- A heat pump water heater uses about a third of the electricity of a resistive tank.
Is an efficient electric water heater worth it?
Resistance tank water heater: about 4,380 kWh a year. ENERGY STAR heat pump water heater: about 1,314 kWh. The difference is worth $1,065 a year in California.
- Replacing one that still works pays back in 1.9 years.
- When yours needs replacing anyway, the extra cost of the efficient model pays back in 1.1 years.
Usage assumed: hot water for a family of four. Typical prices: $2,000 for the efficient model, $1,200 more than a basic one. Work it out with your own prices
Frequently asked questions
How many hours a day does a water heater run?
Typically 2 to 4 hours of element time, depending on household size and shower habits.
Is a tankless water heater cheaper to run?
It avoids standby losses, saving 10 to 30 percent, but electric tankless units need very high amperage.
Should I turn off my water heater at night?
A timer helps if you have time-of-use rates. Otherwise the savings are small because a well-insulated tank loses little heat overnight.
Compare with
Cost by region
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Canadian provinces
Related appliances
- Electric Blanket100 W typical
- Heat Pump (Ducted or Mini-Split)2,000 W typical
- Baseboard Heater1,500 W typical
- Portable Fan (Box or Pedestal)50 W typical
Use the generic electricity cost calculator · Which uses more? Take the quiz