DIY Solar Pool Heater: Homemade Solar Pool Heater


After a long day, nothing is as inviting as a swimming pool. However, unless you do not mind chilly temperatures in the pool, a heater is always a great investment. In addition to allowing you to swim in the evening, it extends the swimming season. 

The cost of heating a swimming pool with electricity can be astronomical – this is one of the reasons pool owners turn to solar pool heaters. In this guide, you will learn how to build a DIY solar pool heater. To make the homemade solar pool heater, we will use affordable materials – the project won’t break your bank account. 

What You Will Need to Construct a DIY Solar Pool Heater

For this project, you won’t need any complicated gear. You can get all the necessary gear from your local hardware store. Below, we have outlined the tools you will need: 

  • 4×4 piece of plywood 
  • 200 feet of 0.5-inch vinyl irrigation hose (black)
  • UV-resistant zip ties 
  • Y adapters 
  • 0.5-inch ball valves 
  • Plumbers grease or pipe dope 
  • Glue 
  • Pump timer 

A Step by Step Guide on How to Build a DIY Solar Pool Heater

1. Make the Solar Collector 

Take a 4×4 plywood piece and paint it black. Next, take a black 200-feet-long, 0.5-diameter-inch vinyl irrigation hose and coil it tightly on your plywood. If possible, avoid sharp corners on the pipe as these increase the power needed to drive water through the pipe. Use UV-resistant zip-ties to secure your hose every foot on the plywood. 

This solar collector will be responsible for heating your pool. Your pool pump will circulate the pool water through the coiled pipe, heating it in the process. 

2. Pipe and Valve Assembly 

To route the pool water to the heater and then back into your swimming pool, you will need to put together a series of “Y” adapters and valves. As noted earlier, we will be taking advantage of the natural flow and pressure of the pool filter pump, instead of investing in a new pump. 

You will need some 0.5-inch ball valves. These will allow you to shut off water to and from your homemade solar pool heater and remove it when the afternoon temperatures make it necessary. 

Water to the DIY Solar Pool Heater

The top should be a smooth 1.5-inch “Y” adapter with a 1.5- to 0.5-inch threaded adapter on 1 side with a 0.5-inch male to the male threaded nipple to a 0.5-inch ball valve and a 0.5-inch threaded to a ribbed adapter that your vinyl hose slides on. You can use 2 hose clamps on every hose fitting to avoid pool leaks.

To ensure a good seal, be sure to sand every smooth surface before gluing. You must avoid gluing any threaded parts. The glue will set long before you get your threads tight enough. To seal the threads, use Pipe Dope or Plumbers Grease. Keep in mind that even Teflon tape may leak due to high pressure. 

Installing the Regulator Valve 

The middle valve – regulator valve – will be a smooth 1.5-inch ball glued to a small piece of 1.5-inch PVC on both sides. By closing the valve partially, the pressure should divert some of the pool water out of your “Y” adapter and into the homemade solar pool heater. 

Installing the Return Valve 

The bottom of the valve assembly will be more of a mirror image of the top part. A ribbed 0.5-inch threaded adapter to the 0.5-inch threaded ball valve to a 0.5-inch to 0.5-inch nipple to a 1.5 smooth adapter, to a smooth 1.5-inch “Y” adapter. 

The flow of the pool water down your 1.5-inch PVC pipe through the 1.5-inch ball valve will draw water from your pool heater into the water flowing into your in-ground or above ground pool

3. Timer Installation

If you allow the water to flow constantly through your solar heater, the hundreds of gallons of cold water in your in-ground or above ground pool can easily overwhelm the ten or so gallons of water in your solar heater. The water wouldn’t have enough time to heat up before it gets back in the swimming pool – even with your heater, you would still have to swim in cold water

To solve this issue, you will need to install an outdoor timer for your pool pump. While the pump may need to run for a couple of hours a day to filter the pool, you can set the timer to turn the pump on and off at 0.5-hour intervals between noon and 6.00 pm. This will give the water in the solar heater enough time to heat up before it is pumped back into the swimming pool. 

Enjoy Swimming in Warm Waters 

When you follow every step we have described above to build your homemade solar pool heater, the water flowing back into the pool when the heater is operational should be about 99 degrees Fahrenheit. This should keep your entire pool at an ideal temperature of approximately 84 to 86 degrees Fahrenheit. This should allow you to have a good time in your swimming pool every time you put on your swim cap and swimming gloves


Q: Do Solar Pool Heaters Work?


Yes, solar pool heaters do work. A solar heating system involves pumping the water from the swimming pool through a series of tubes – known as a solar collector or solar absorber – mounted on the ground or a building roof. The sun’s free energy heats the water as it circulates through the tube series, returning it back to the swimming pool at an elevated temperature. Over time, the solar heater can boost the pool temperature to the desired level.

Q: How Can I Heat My Pool Cheaply?


Solar heaters are one of the cheapest ways of heating a pool. They eliminate the need to pay electricity bills while keeping your pool water warm throughout the swimming period. With the steps outlined above, you should be able to construct a cheap solar heater. Our article on cheap ways to heat a pool should give you more ideas on how to keep your pool water warm affordably

Q: Will a Black Tarp Heat a Pool?


Although a black tarp may not heat your pool directly – say as a solar heater would – it can help keep the pool water warm. Covering the swimming pool with a black tarpaulin will eliminate heat loss through evaporation. In extra cold weather, you may have to use an additional heating option, say a pool heat pump, to raise the water temperature even though you have already installed the black tarp.

Globo Surf Overview 

To have a good time in the swimming pool, heating is often necessary. Most types of heaters – including electronic and gas heaters – tend to be too expensive. These types of heaters can be avoided by making use of cheap DIY solutions. 

Outlined above, are the steps you need to follow to make a DIY solar pool heater. By following the steps, you should be able to build a homemade solar pool heater that raises your pool temperature to at least 84 to 85 degrees. To ensure maximum heating, be sure to keep your collector in an area where it can access direct sunlight.

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My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!