What does a heat pump water heater cost to run?

Run the numbers on your own use

Change any of these and the figures update. The defaults are the typical case described above; your rate is the input that moves the answer most.

Why this is lower than the number you will see elsewhere

Almost every published answer to this question multiplies the rating on the label by the hours the appliance is switched on. For a heat pump water heater that gives 4,818 kWh a year, or $884.

Runs the compressor far longer than a resistance tank fires its elements, but at about an eighth of the power. The top of the watts range is the backup resistance element.

The arithmetic, step by step

Nothing here is hidden, so you can check it or change it. Working in the order the formula runs:

1. 550 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 20% — the share of its in-service time it is really pulling that. Runs the compressor far longer than a resistance tank fires its elements, but at about an eighth of the power. The top of the watts range is the backup resistance element.
   That gives 110 W averaged across the hours it is on.
3. × 24 hours a day × 365 days — A 50-gallon hybrid in a basement, resistance backup rarely engaged.
   110 × 24 × 365 ÷ 1,000 = 964 kWh a year.
4. × 18.34¢ — the US average residential rate for June 2026.
   964 kWh × 18.34¢ = $177 a year.

Change any assumption in the calculator above and every figure on this page moves with it. The two that matter most are your rate, which varies 4× across the country, and the hours — the duty cycle is a property of the appliance, but the hours are a property of you.

How sensitive is that number?

A single figure invites more confidence than it deserves. Here is the same appliance under assumptions either side of the default, so you can see how much of the answer is the appliance and how much is the guess about how you use it.

Everything else held at the default. The spread here is the honest error bar on the headline figure.

What it costs per hour, day and month

At 18.34¢ per kWh, the US residential average for June 2026.

The thing worth knowing

It draws heat out of the air in the room it stands in, which means it also cools and dehumidifies that space. In a basement that is a bonus; in a small closet it can starve itself and fall back on resistance heat, which erases the saving entirely.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this heat pump water heater costs $508 a year in Hawaii and $126 in Nevada — a difference of 4×.

Cost of running one heat pump water heater for a year, by state. Residential average price, EIA June 2026.

Other water heating and pumps costs

• Hot tub

  $602 a year

  A 400-gallon tub held at 102F year round, well covered.

• Pool heat pump

  $576 a year

  Holding a residential pool at swimming temperature through an extended season.

• Electric water heater

  $499 a year

  A 50-gallon tank serving a household of three to four.

• Pool pump

  $396 a year

  A single-speed pump on an eight-hour timer through the season.

• Koi pond pump

  $241 a year

  A pump circulating a mid-size koi pond through its filter, year round.

• Septic aerator pump

  $112 a year

  An aerobic septic system running as intended.

Questions

Source: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A, June 2026. U.S. Government work, public domain.

How every figure on this page is computed · Where the data comes from