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There’s nothing better than going for a swim in a nice, heated swimming pool on a breezy day, but electric pool heaters use quite a bit of electricity. A alternative energy of sunlight to sustainably warm up your swimming pool. While solar pool heaters are relatively cheap, building your own is even cheaper, and more fun. If you’re the type who likes to build, you can design your very own. The materials are cheap and readily available, and it can be done in a day if you have some help. Keep reading to learn how to build your own DIY solar pool heater!

Why Build Your Own Solar Pool Heater?

The better question is, why not? Solar water heaters tend to be inexpensive, even more so if you build your own. You can find the materials at a local hardware store for less than half the price of a high-quality solar pool heater. This guy made one for just $25 bucks.

It doesn’t take much time either. Two to three people can build one in a matter of hours. Even if you make some blunders, which you will, you’ll have yours set up and running within a day. While it can be done alone, it’s recommended to have at least one other person there to lend a hand.

While it’s nice to order a premade solar pool heater from the internet, building your own gives you the freedom to create your own design. There’s also no warranties to worry about, so you can modify it as much as you want. If it breaks or malfunctions, you don’t have to put the blame on the manufacturer, since you made it yourself. You know how it was built, so you know exactly how to fix it.

Paired with a solar pool cover, your own DIY pool heater will keep your pool warm enough for enjoyable swimming year-round.

Making Your DIY Solar Pool Heater

Building a DIY solar heater is more simple than it seems. The materials are easily found at a hardware store. You’re going to need wood to build a frame, an irrigation hose, a transparent hard plastic cover, and a pool pump. You should also keep a thermometer handy to check the temperature of the water.

The Frame

DIY Solar Pool Heater Frame

The first step is to build a frame. This is going to be what houses the irrigation hose which collects the heat from the sun, similarly to how solar water heaters heat water for your home. You can build the frame in any shape you like, but to keep it simple, it’s best to use a square or rectangular shape. Remember to build the frame according to the size of your pool. More water needs more volume and vice versa.

Use a large piece of plywood for the backing of the frame, then cut down some two-by-fours to enclose the borders of the backing. You can also use a two-by-four to bisect the backing and create two large areas to collect heat, like this guy did. This center beam will also double as a support beam.

It’s very important to paint the frame black to help absorb heat from the sun, replicating the typically-black design of solar panels. You can paint the wood pieces separately before you build the frame, or you can paint the frame as a whole once it’s put together.

The Hose

The hose is where the pool water will collect the sun’s energy. A black irrigation hose is your best bet. Like the frame, it’s important that your hose is black to maximize the amount of heat collected by the sun. The length of the hose depends on how big your solar pool heater will be, and how far it will be from your pool and the pool pump.

Installing the hose may be one of the more difficult steps of making your DIY solar pool heater. The hose has to be coiled inside the frame in a spiral pattern. It’s best to start from the outside and work your way in. You want to use the maximum surface area possible when you coil your hose, so the pool water can collect as much heat as possible. Although your frame may be rectangular in shape, you should coil the hose in a circular pattern to avoid making kinks in the hose. If you do coil the hose in circles, you will be losing some space in the corners. Some people get around this by coiling the hose in a snake pattern. The hose is run straight through the frame from end to end, then curves back toward the other end, like drawing the letter “S”. This pattern is repeated down the entire frame. Though this maximizes surface area, it’s more difficult as it may put some kinks in the hose if the curves are too tight.

If using a circular coiling pattern, you can run the hose in through the outside of the frame, and out through the center, or in one side and out the opposite end. If using a snake pattern, you’ll be running the hose in through the top of the frame and out of the bottom from the opposite end. There may still be a significant amount of space in the center of the frame once the hose is coiled. This is a good place to drill in an extra support beam using a two-by-four, like this guy did his. This will come in handy when applying the cover later on.

The hose coiled around the frame

Fastening the hose is best done with black zip ties, again, black to maximize the heat absorption. White zip ties or metal fasteners will reflect too much light. Pick points along the route of the hose to which you’ll fasten your zip ties. Many find it best to use cardinal directions (up, down, left, right), as it makes the task simple, especially if you’re coiling the hose in a circle. If you’re using a snake pattern, your fastening points should be in two straight lines down the frame, about two-thirds of the way toward the center. Drill holes at these fastening points, but do it before you coil the hose into the frame. Once the hose is on the frame, use the zip ties to secure the hose.

Before moving on through to the next step, run some water through the hose and make sure it flows correctly. Check for holes and kinks, and do a temperature check of the water before and after it runs through the hose to check that it works correctly.

The Transparent Cover

Now that you have the base of your heater complete, it’s time to put the finishing touch. Enclosing the frame in a transparent sheet will protect the hose from the elements as well as create a greenhouse effect to help trap the sun’s heat. Depending on the type of cover, the temperature inside the solar heater can reach well into the hundreds, more than enough to heat up your swimming pool.

The transparent cover

The cover should be made of a hard plastic like Lexan or acrylic. Glass is not recommended, you don’t want to have an accident and shatter the glass. Ideally, you want a completely transparent cover, avoid covers that are colored or slightly opaque. Though it’s best to have a flat cover, many DIY solar pool heaters are built with corrugated covers as well.

The cover should be drilled into the support beams that border the outside of the frame. If you have a support beam bisecting the middle of the frame, you should drill it down there as well.

Make sure to drill in the cover with care. Being that it’s made of plastic, you don’t want to drill too hard, as you might crack the sheet cover.

Though a cover is recommended, you can still make a DIY pool heater without one. This woman made two minimalist heaters without covers or even a wood housing.

Pumping the Water and Setting the Flow

Great job! You’re almost done building your DIY pool heating system! Now it’s time to get that water circulating. While some may use a separate pump to get the water to flow through the solar heater, others find it easier to use the pool’s filter pump.

The major thing here is to set the right flow rate. If the water were to flow through the heater with no control, it will flow too fast to collect any heat. If it flows too slow, it will get way too hot. Use a valve to set the proper flow rate. Its also important to remember that too slow a flow rate will get hotter water, but the pool won’t heat up if the water volume is low.

Check the Temperature

Now that your system is up and running, it’s time to check the temperature. Check the temperature of the water in the pool compared to the outside air temperature. Then take the temperature of the water coming out after it’s been running for a few minutes. Adjust the flow rate to get the optimal temperature. After about an hour or two, check the temperature of the pool. It should be getting warmer, but don’t let it get too hot. Remember, your heating up a swimming pool, not a jacuzzi!

Mounting Your Solar Pool Heater

Now that your heater is ready to go, it’s time to set it up! Where you place your it is entirely dependent on the layout of your home and the available sun. If you have a wide-open space with minimal shade near the swimming pool, then you don’t have to go very far, you can set it up right next to the pool. If your pool area is rather shady, you should find a sunny spot on your property to place the pool heater. Many DIY solar pool heaters are built with legs and swivels to hold them up and keep them facing towards the sun. Folding legs are best to make it easy to transport. While it is a bit of extra work, it can make your solar heater that much more effective.

If there’s no shady space on your property, you might have to mount it on a wall or roof facing the sun. This is a bit more difficult, especially if you’re setting it up on a roof, as you don’t want to cause any structural damage to your home. If you are fixing your heater to the roof, you may need some mounting brackets to make the job easier. To maximise the efficiency of your solar pool heater, it should be mounted in the same direction as you would mount solar panels (learn the strategic placement for solar panels).

Still Want To Buy A Solar Pool Heater?

If your not the hands-on type, or if you just don’t want to put the effort into building your own DIY solar pool heater, then no worries! There are a ton of high-quality solar pool heaters outh there for you. Choose one that’s right for you!


Solar pool heaters are an environmentally friendly way to heat up your swimming pool. While there’s a large selection of solar pool heaters online, you can also build a DIY solar pool heater at home in your garage. The materials to build one cost less than half the price of a quality solar pool heater, and you can build it within a day. It does take some elbow grease, but the enjoyment of a nice, warm pool is well worth it!

Frequently Asked Questions

What is a solar pool heater?

A solar pool heater uses the sun’s energy to heat up the water in a swimming pool. The pool water is run through a series of black tubes that collect energy from the sun, which then route the pool water back to the pool.

Why should I build a DIY solar pool heater?

Building a DIY solar pool heater is cheaper than buying one online or at a pool store. You’re free to modify your solar pool heater and create your own designs.

What materials do I need to build a DIY solar pool heater?

You’re going to need a few sheets of plywood and some two-by-fours to build the frame, a black irrigation hose to run the water through, and a hard plastic transparent sheet to close the housing. You’re also going to need black paint to paint the frame, a pool pump to regulate the water flow, and a thermometer to check the temperature.

What are the pros and cons of a solar pool heater?

Solar pool heaters heat your pool for free, utilising only the energy of the sun. As such, there are few cons attached. The only negatives are to do with the availability of sunlight: the same disadvantages which tend to affect solar panels.

Editorial Contributors
avatar for George Duval

George Duval

George Duval is a writer and expert in sustainability and environmental studies. After graduating with a B.A. in Sustainability from Florida International University, George began dedicating his life to researching new ways to make the world a greener place. His expertise ranges from organic gardening, to renewable energy, to eating plant-based diets. He is currently writing and editing for a number of publications, most of which focus on the environment.

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