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How to Heat a Swimming Pool (Without a Heater)!

By Spencer - Updated On: 12/29/20

Ahhhh, a heated pool. There’s nothing quite as glorious as taking confidence in knowing that when you plunge into your pool you’re not transforming into a polar bear.

What? You mean that jumping into an unexpectedly cold pool wasn’t the experience you were going for? How about spending oh-too-long easing your way into liquid frost on a hot summer day.

Wouldn’t it be nice to not only be able to enter your pool immediately, without the shock of the instant temperature change to your body, but also extend the swim season year after year? Sure would!

While a pool heater is the most efficient method for scoring a warm watered pool, there are other routes you can take to help heat up your pool and keep it open for a longer season.

HOw to heat a pool without a heater

Before we start, here are a few things to be aware of:

Not all pools will have similar results due to various factors. For example, the weather/climate and pool location play key roles in how your pool will react to these different heater types.

Picture this, in our home state of Tennessee, summer days will reach temperatures near 100 degrees Fahrenheit, while nighttime temperatures will only differ by 10-15 degrees.

However, if you are in Arizona for example, it may be upwards of 100 during the day and below 60 at night. This can cause quite a fluctuation in customer experiences. Similar to this is that a pool in humid climates will retain heat much better than that of a pool in a dryer climate.

You’ll also want to keep in mind that a pool surrounded by trees and/or shadow-casting buildings will not receive near as much sunlight as a pool that's out in an open area with direct sun exposure. The key to heating any pool without a heater and by solar means is SUNLIGHT. As much sunlight as possible. With that said, and those tips in mind, let’s continue!


Everyone will agree on the simple matter that having a swimming pool is great for cooling off on those hot summer days. But not everyone fancies having an overly chilly pool.

Fortunately, we offer a very affordable item called a solar cover (also known as a solar blanket).  Our solar covers are made to give you the maximum heating and insulation properties, with thermal bubbles that retain heat at night and on cloudy cool days.

Our transparent blue cover or Magni-Clear cover helps ensure that the sun's heating rays are reaching your pool water, allowing your pool to heat up to 15°F warmer than if it were uncovered, depending on your location.

Royal Swimming Pools Solar Cover-1

All our covers are U.V.-protected so they last under the most intense sunlight. We offer solar covers for in-ground AND above ground pools. This is a great alternative route for those who want to keep their pool open longer while also taking a very affordable route. Solar covers will also help with chemical use by keeping some debris out of your pool.

The solar cover does require sunlight for optimal performance but can help some just by retaining the ambient heat drawn from the air. Even in full shade, a solar blanket helps retain heat. It acts as a thermal blanket at night, holding that heat in, no matter where it comes from, outside temp, gas, electric, or solar heat; making a solar blanket highly recommended with any heating system, simply to help maintain the energy used for heating.

IMPORTANT:  Due to the rise in demand caused by the 2020 pandemic, solar covers have been experiencing delays industry wide in both manufacturing and shipping. If you're hoping to extend your swim season or just want to warm up your warm a bit, you'll want to place your order as soon as possible as these have been a hot commodity and spent most of 2020 out of stock and unavailable. More on purchasing pool products during or even post pandemic can be found here.Shop Solar Covers


A solar panel heating system circulates pool water through solar panels mounted on the roof and uses solar energy/heat from the sun to warm the water as it returns to the pool. It sounds complicated but this system is a fairly simple DIY project. While this method is a fair bit more expensive compared to the solar blanket, it is very affordable compared to electric or gas pool heaters.

However, as with any heating system, you may still want a solar cover to retain the heat that you create from the solar panels (especially if your pool doesn’t get that much direct sunlight).  We offer both Above Ground and Inground options for Solar Panels!

Royal Swimming Pools Solar Panels

We also offer an even more affordable way to heat your pool which also retains chemicals inside the pool. 


Although not the most effective, solar pills are a very economical way to heat up your pool. Using this method, you are supplied with a Solar Pill, which is basically a ball filled with liquid solar.  The process is very technical: You poke a couple of holes into this object and place it directly in your skimmer. That’s it.

As your pool circulates over time, the pill will begin to dissolve and blanket an alcohol-based film across the top layer of the surface of the water which retains heat while also attracting sunlight to your pool.

You may need to purchase more than one to cover the complete surface of your pool if you have a larger pool kit. Good news here is that your pool will still be safe to swim in, so you would be able to indulge in your pool as it is heating up as opposed to a solar blanket where you wouldn't be able to perform swimming activities due to it covering your pool. (Learn more about liquid solar covers here.)

Shop Liquid Solar Blankets

Royal Swimming Pools How to Heat a Pool without a Heater

As you can see, we offer multiple various methods you can use to heat up your pool and help retain that heat. As mentioned these are also wonderful considerations to pair with your existing gas or electric heater! We know that price has a lot to do with what your final decision will be, so we offer very affordable and economical options for everyone.

We are always here to help you get a better understanding of which product does what so if you still have questions don't hesitate to reach out!

Swim Happy (and stay warm)!