DIY Solar Pool Heater: 4 Ways to Use the Sun to Heat Your Water

Swimming in a warm pool is a summertime favorite for many, but the cost of heating a pool can swiftly curb the excitement. A DIY pool heater is a cost-effective and environmentally friendly solution that utilizes the sun's power to warm your pool water. With just a few simple materials and some basic DIY skills, you can save money on your energy bills and enjoy a warm pool all summer long.

How Does a Solar Pool Heater Work?

Most solar pool heaters take the water from your pool with a pump and send it through a solar collector to heat your pool water. In other words, the solar collector can capture heat from the sun’s rays. As the water goes through the collector, it retains the heat as it goes back to your pool. The solar pool heater continues to recirculate your pool water through the solar collector and back. 

Solar collectors are typically tubes or plates consisting of a variety of materials that attract the sun. It can be as simple as black tubing because the color black absorbs more heat than it reflects. Other materials include copper tubing, aluminum plates, or glass coverings.

How Much Does It Cost to Install a Pool Heater?

The cost to install a pool heater depends on the type of heater. A gas or propane pool heater will cost anywhere from $1,500 to $6,000. Similarly, an electric pool heater costs $1,000 to $6,000 but has much higher operating costs than gas heaters.

For a more energy-efficient pool heater option, choose a heat pump pool heater for $2,500 to $7,500 or a solar-powered pool heater for $2,500 to $9,500. While the initial cost of a solar heater is a bit higher than other options, it will pay for itself in the long term since they harness solar energy from the sun.

Unlike the DIY solar pool heaters described below in this guide, a standard solar-powered pool heater uses a factory-made solar collector and more advanced equipment, including a pump, strainer, filter, flow valves, and a separate pool heater unit. Generally speaking, solar-powered pool heaters from a manufacturer will last longer and be more effective at heating your pool, hence the much higher price point.

You will save anywhere from $300 to $1,000 on labor if you install a pool heater yourself; however, most installations require modifying electrical or gas, which are tasks you need a pro to take care of. Contact a pool heater installer near you for pricing.

Prepping to Build Your DIY Pool Heater 

Before building a solar pool water heater, it’s important to know which direction and angle will capture the most sunlight in your area. In the Northern hemisphere, facing solar panels toward the south is typically the best choice, along with angling them between 30 and 45 degrees. The exact formula will vary depending on where you live and the time of year. 

How to Build a DIY Solar Pool Heater

There are plenty of DIY solar pool heater ideas out there. We’ve gathered our top choices below with step-by-step instructions on how to build them.

Using a Black Hose and Wooden Tray

This DIY pool heater is commonly called a black hose pool heater. The heater sends your pool water through a coiled-up black hose that captures the sun’s rays and heats up the water. 

Start by creating a wooden tray for the black hose coil to sit in. You’ll need to prop the tray up at an angle to maximize the sun intake. Build a tray about 4-by-4 feet using plywood with wood framing along the edges for added strength. To harness more of the sun’s rays, paint the tray with black paint or line it with black fabric or felt. 

Take about 200 feet of 1/2-inch black irrigation hose and coil it up inside the tray. The hose should lie flat, wrap around in many spirals, and not overlap on itself. Secure the hose to the plywood with zip ties and screws. Have the hose begin and end at two different sides of the tray, so you have space to hook up the pump.

Attach a hose connector to each end of the black hose and connect one of the ends to a submersible pump. Place both the submersible pump and the other end of the hose into your pool. Angle the solar heater tray, so it faces the most sunlight possible, then turn on the submersible pump to begin to heat up your pool water through the black hose.

Using a Flat Plate Solar Collector

A flat plate solar collector adds an extra layer to the type of solar collector described above using a black hose and wooden tray. Rather than using painted plywood as the backdrop for the black hose, use a flat plate material that instinctively absorbs heat, such as a large sheet of copper or aluminum. Additionally, add another flat plate like a sheet of glass over the black hose to attract and contain more solar rays.

Using Black Tarp and Hula Hoops

This DIY pool heater is the least expensive and easiest to construct. Grab a few hula hoops, black tarp, duct tape, and pool noodles. 

Wrap a black tarp around a hula hoop, covering it completely. Cut away any excess and secure the tarp to the hula hoop with duct tape. You will use pool noodles to ensure these hula hoop solar panels float in your pool. Cut a pool noodle into four sections and cut a slot along the side of each.

Insert the hula hoop into the slot along the side of the pool noodle. Install all four pool noodle sections equally spaced around the hula hoop. The pool noodles should stay on the hula hoop, but you can further secure them with large zip ties as needed. Consider the size of your pool when determining the size of your pool heater. Repeat this process with each hula hoop. 

Make multiple hula hoop solar panels for your pool to maximize the surface area that attracts the sun’s rays. These floating solar panels may not be the most effective pool heating option, but they will attract some of the sun’s rays to your pool. 

Using Corrugated Metal Roofing

This DIY solar pool heater uses a piece of corrugated metal roofing to create an open-flow solar collector. You will need a few corrugated metal roofing panels. Start by connecting them together and building a frame around them with wooden boards. 

Attach legs to the frame that allow the solar panel to tilt at the proper angle so water will flow from one end to the other. Paint the corrugated metal roofing panels black to improve the sun absorption.

Attach a piece of PVC pipe to the top of the corrugated metal panel with multiple holes drilled into it that line up with each valley in the metal. Place a submersible pump into your pool and connect a hose from the pump to the PVC pipe. With this setup, water will be pumped from your pool to the corrugated metal solar collector and begin to flow down the metal panel.

Place another PVC pipe at the bottom of the solar collector, but cut it in half into a channel that will collect all of the water. Connect an additional PVC pipe to the PVC channel to send the heated water back to your pool.

Tips to Troubleshoot Your DIY Pool Heater 

If you run into any trouble while building your DIY pool heater, these troubleshooting steps should help.

• Check your connections: If the pool heater you’ve chosen requires piping or hoses, ensure the connections are tight and secure to avoid leaks. The connections on a hose are likely threaded, and you’ll need to hand-tighten them—but don’t overtighten with a wrench. You can also use PVC glue for any PVC connections.

• Look for obstructions: After ensuring your solar collector is at the right angle and direction to collect the most sunlight, ensure no obstructions are blocking the intake. Shadows from trees and structures will impede the ability of your solar heater to work properly.

• Consider the weather: Solar heaters will not be effective in cloudy, rainy, or foggy weather conditions. Before deciding your DIY solar heater doesn’t work, make sure the weather outside is not playing a role in the issue.

DIY Solar Pool Heater vs. Hiring a Pro 

The DIY pool heaters described above are easy DIY projects. You can build each in an afternoon’s time by purchasing the proper materials and supplies, and you’ll likely spend less than $200. If you’re looking for a more substantial pool heater than these DIY solar pool heaters, leave it up to the professionals. The cost of a new pool heater installed by a pro is anywhere from $1,700 to $4,000.