What does a hot water recirculation pump 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 hot water recirculation pump that gives 394 kWh a year, or $72.

A pump with no timer and no thermostat runs every hour of the year. Fitted with the timer most of them ship with, it runs perhaps four hours a day.

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. 45 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 100% — the share of its in-service time it is really pulling that. A pump with no timer and no thermostat runs every hour of the year. Fitted with the timer most of them ship with, it runs perhaps four hours a day.
   That gives 45 W averaged across the hours it is on.
3. × 24 hours a day × 365 days — A continuously running pump on an untimed loop.
   45 × 24 × 365 ÷ 1,000 = 394 kWh a year.
4. × 18.34¢ — the US average residential rate for June 2026.
   394 kWh × 18.34¢ = $72 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

This is the single most common large always-on load in a house, and almost nobody knows it is there. It costs more per year than every phone charger, television standby and smart speaker in the building combined, by a factor of about twenty. It also circulates hot water through uninsulated pipe continuously, so it adds to the water heater’s work as well as its own draw.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this hot water recirculation pump costs $208 a year in Hawaii and $52 in Nevada — a difference of 4×.

Cost of running one hot water recirculation pump 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.

• Heat pump water heater

  $177 a year

  A 50-gallon hybrid in a basement, resistance backup rarely engaged.

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