How Much Does it Cost to Heat a Pool?

Little girl wrapped in a towel and shivering after being in the pool

If you’re planning to crank up the heat on your new swimming pool, you might be in for a nasty surprise when the bill comes due. Pool heaters are great for keeping the water comfortable and extending the swimming season into cooler months, but they can be very expensive to run.

How expensive?

Perhaps expensive enough to be a big factor in deciding whether to get a pool in the first place.

As with other pool maintenance costs, the final tally for heating depends a lot on where you live and your pool’s setup. But, unlike expenses such as water or chemicals, the difference between the low and high end of the price range is enormous.

Whether you pay a little or a lot depends largely on how cold your pool water is at the start, and how warm you want it to be.

How Warm Do You Like It?

When it comes to heating a pool, every degree counts. The U.S. Department of Energy estimates that for every one degree you raise your pool’s temperature, energy consumption goes up 10-30% (depending on where you live).

Regardless of whether you’re using gas or electric, or what your energy rate is, the costs add up quickly if you have to heat your pool from a cold starting temp.

Most people are comfortable swimming in water temperatures of 78 degrees or higher. However, if you tend to get chilled easily, you may want it warmer. Seemingly small differences in personal preference can have an outsized impact on your heating bill.

Whatever your target temperature is, it’s tough to get a precise picture of how much heating you’ll need to hit it. Your pool’s natural temperature depends not just on the current air temperature, but the overnight low, the time of day you’re swimming, and many other factors.

The good news is, some of these factors are in your control.

Reducing the Cost of Pool Heating

Pool experts agree that the best thing you can do to minimize heating costs is cover your pool, thereby vastly reducing the amount of heat loss from evaporation.

The Department of Energy’s website illustrates this in shocking detail with a table showing how much a pool cover might save you in different parts of the country. For example, if you use a heat pump in Chicago, adding a pool cover can drop your annual heating costs from $810 to $105 (caveat: there are a lot of assumptions built into this that may not apply to you).

Though it requires an investment of money and space, a solar heater can also save you a lot on heating. A solar pool heater can’t necessarily replace a traditional electric or gas heater, because it can typically only raise water temperature a few degrees. However, as demonstrated, those few degrees can make a big difference on your heating bill.

Here are a few other ways to keep your heating costs down:

1. Build a smaller pool. At the risk of stating the obvious, having a smaller pool means there’s less water to heat.

2. Block the wind, not the sun. Wind leads to more evaporation and cooling, so consider erecting barriers to keep it out of your pool area as much as possible. On the flip side, you might want to remove tree limbs or other things that throw shade on your pool.

3. Pick your battles. There are days when it’s just not worth it to heat up a chilly pool – especially if the air temperature is also cool enough to hamper your enjoyment. Every pool owner has to decide for him or herself what a tolerable temperature is, and whether a day in the pool outweighs the costs.