Most folks would love to be able to use their swimming pool for as many days of the year as they possibly can. But where you live, and your local climate, can have a major impact on pool availability -- especially if you live in a more northerly state with more than its fair share of cold and/or snowy days.
At River Pools, we speak with hundreds of folks across the greater Washington DC Metro area (Virginia, Maryland, and the nearer parts of West Virginia) each year about inground pool projects. Many of these prospective pool buyers have questions about pool heaters, and we're always happy to answer these questions.
But today, we're going to distill the most common pool heating questions into one helpful article.
We want pool buyers (and owners) everywhere to have an easy reference point on the benefits of heating your pool, the different heating options available to you, and what you can expect to spend on each type of pool heater, both in terms of upfront costs (purchase and/or installation), and on an ongoing month-by-month basis for electricity or fuel and regular maintenance.
Why should you heat your pool?
Great question! The swim season in many temperate areas (most of the northern half of the United States) may only last three or four months. Unless you're in Miami, you'll have a fair bit of time each year in which it's just too cold to properly enjoy your inground swimming pool.
However, using a pool heater can often extend your swim season by roughly two months, or even more, depending on location and climate. This means another month of swimming in the spring before everything's in full bloom, and another month in the fall after the leaves start to turn yellow and fall from your local trees (hopefully not into your pool, but that's one good reason to consider using a swimming pool cover as well).
We all know how much the whole family enjoys a good dip in their backyard swimming pool. Closing time can be a bummer. A pool heater you and your family can maximize the fun.
What are the main types of pool heaters?
There are three major kinds of pool heaters:
- Solar
- Heat pump (electric)
- Gas or propane
How do pool heaters work?
Solar pool heaters can be very efficient all year round in southern climates.
Solar heaters will also extend your swimming time in more temperate northern climates.
With a solar pool heater, your existing pool pump will circulate pool water through the heater, which is typically mounted on the rooftop or on an elevated frame built in your backyard. A solar pool heater is somewhat similar to a solar panel, in that it uses the sun's energy to produce something immediately useful -- in this case, warmer pool water.
The downside to solar pool heaters is that the entire system needs to take up an area equal to at least at least 50%, and up to 100% (and occasionally more), of your pool's surface to work properly.
Solar energy is technically free, but your pool pump needs to run to move pool water through your solar heater so it can properly operate. This often adds to your electric bill. If you've got enough space on your roof after installing a solar pool heater, you might be able to offset this expense by adding solar panels to generate electricity -- but this, of course, only adds another substantial upfront cost to your pool heating project.
Electric heat pumps actually use a form of solar energy, too.
Didn't see that coming, did you? Electric pool heaters pull warmer air from the environment, which has of course already been heated by the sun, to raise your pool water temperature. This warm air is sucked into the pump, enhanced, and fed into the pool water.
An electric pool heat pump generally requires temperatures of at least 55°F (12°C) to function properly. They tend to be less expensive to run, but there are clear drawbacks to using something that'll only work when it's a bit brisk outside. Don't plan on any wintertime pool parties with an electric heat pump!
If the ambient temperature changes dramatically overnight -- as it often can in some desert climates -- you won't be able to take any (heated) midnight dips, either.
Gas-powered pool heaters will burn either propane or natural gas to heat your pool water. This allows the heater to operate in any outdoor temperature condition, as long as the heater can continue to burn its fuel.
Gas pool heaters burn their fuel in combustion chambers, heating copper coils connected to the pool pump. Your pool water will run through these copper coils, warming quickly before returning to your pool with a much more pleasant temperature.
A gas pool heater can be a bit costlier than the other two types of heaters, especially if you plan to run it frequently (fuel costs can add up). However, it's the only type of heater that'll work when it's cold and dark, and it'll bring your pool water up to an ideal temperature much faster than either a solar heater or an electric heat pump.
How can electric heat pumps save money?
Solar heaters might use "free" energy, but you'll still need to run your pump to make use of their warming functionality.
This extra pump time can often increase electricity costs by anywhere from $300 to over $1,000 a year, depending on how determined you are to keep your pool water warm.
Gas pool heaters regularly cost anywhere from $300 to $500 a month to operate, depending on the fuel you use and how often you want to heat your pool water.
Electric pool heaters are more efficient than other pool heaters, typically costing their owners roughly $50 to $100 per month in added electric expenses.
Many homeowners we've spoken to who opt to install pool heaters (19 out of 20 pool buyers) choose electric heat pumps, simply due to their dependability and comparatively lower operating cost.
Electric heat pumps often extend the average pool's usability by two to three months, depending on your location and climate. An electric heat pump's minimum temperature requirements of at least 55°F will determine how long it can extend your swim season.
In warmer Gulf Coast states, like Texas or Louisiana, an electric pool heater can efficiently regulate temperatures during most of the year.
In temperate mid-Atlantic states like Virginia, an electric heat pump can extend "pool season" for roughly two months. In colder Midwestern states like Ohio, pool heaters are not optional. Heating is required to keep your pool water temperatures comfortable for more than a few weeks of perfect weather, although you probably won't need a pool heater in midsummer when temperatures are at their highest.
Solar vs. Electric Heat Pump vs. Gas Heater
| Solar Pool Heater | Electric Heat Pump | Gas Pool Heater |
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Use the sun’s energy to warm water circulating through the heater. |
Pull ambient warmth from the air to heat your pool water. |
Use propane or natural gas to heat copper coils, which quickly transfer heat to circulating pool water. |
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We hope this guide helped you work through your options if you're interested in heating your pool or just thinking about what you might do in the future.
For more information on the three types of pool heaters, and to learn about a whole lot of other pool accessories, take a look at our Fiberglass Pool Options and Accessories article.
You can also download our comprehensive guide, How to Buy a Fiberglass Pool in 2021. It's free, and you can grab it by clicking the button below:
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Editor's note: This article was updated on September 8, 2023.