What’s the Cheapest Way to Heat a Pool?

Every day you can swim in the pool is a good day. Unless, of course, the water is so cold that it leaves your teeth chattering uncontrollably. Getting your pool’s temperature just right is a matter of the season, geography, and – not to be overlooked – personal preference.

Of course, it’s also a matter of money. As mentioned in a previous article, the cost of heating a pool in 2023 can easily get out of hand. Fortunately, while you might not be able to control the weather or the cost of energy in your area, you can choose which heating method you use.

So, what’s the cheapest way to heat a pool? The short answer is solar, but the short answer might not be the right answer for you. A lot depends on how much heating you need, and whether you’re prepared to spend upfront to save money over time.

Solar Blankets

Evaporation is the main culprit when it comes to chilly pool temps. Thus, any sort of pool cover will help keep the water comfortable in between uses. However, specially designed solar pool covers (aka solar blankets) are ideal because they not only hinder evaporation, but also trap heat from the sun.

The best part is that solar pool covers – along with similar products such as solar rings – are relatively cheap and entail no ongoing costs. The downside is that using them isn’t quite as convenient as turning a knob on a conventional pool heater. Also, there’s not a lot of fine control over the amount of heat they supply, and you may wind up needing active heating from other sources.

Solar Heaters

The next cheapest way to heat a pool is through a solar heater. The cost of running a solar pool heater is essentially free, aside from occasional maintenance. The difference is that a solar heater is a lot more expensive to install – often even more expensive than a conventional heater. Another potential drawback is the necessity of using solar panels, which some people find unsightly.

As with solar blankets, there’s a limit to how much heating a solar heater can do. The good news is that you can easily combine it with other methods to get all the heating you want at the lowest possible price.

Electric Heat Pumps

Heat pumps draw in warm air from the environment to heat up pool water, similar to an air conditioner in reverse (for a detailed description of the process, see this article). While they cost more to install than gas heaters, they’re cheaper to run and typically last much longer. The only downside is that they work less efficiently the lower the air temperature gets, which could be a problem if you want to use your pool or spa in truly chilly weather.

Gas Heaters

Gas heating is the most straightforward and common type of pool heating. Some might question why it’s even mentioned in an article about the cheapest pool heating options, because it’s the high cost of gas heating that most people are looking to avoid. The reason is that it’s fast, and could be an economical choice for on-demand heating of pools that are infrequently used. A gas pool heater is also a good candidate to pair with solar options because it adds power and reliability to the mix.

As you can see, there are a lot of options for heating a swimming pool, and all of them have their pros and cons. Choosing a pool heating solution often means making some tradeoffs to get the heating you need at a cost you can afford. But then, it’s all worth it if it means more perfect days in the pool.