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DIY Solar Water Heater: Everything You Need to Know!

Written by K. Miller / Fact checked by J. Fussell

diy solar water heater

You don’t have to sacrifice the convenience of a regular hot water system when you set up a solar-powered heating system. Such a system is mainly designed to connect to a gas water heater or conventional electric water heaters.

With all solar hot water heater systems, DIY or not, you must install the panels in areas that could generously captivate direct sunlight.

In this post, we’ll uncover the reason why considering a DIY solar water heater is an excellent option for you.

In general, it’s best to utilize the south-facing section of your roof. While a west or an east-facing roof would also work, you will require extra panels to capture the same amount of heat.

What Is a Solar Water Heater?

A solar water heater refers to a device that absorbs the sun’s energy to heat water. It can serve as a very cost-effective means to produce hot water for your bathroom and a warm shower for the whole family.

Such a water heater device allows remarkable energy savings since solar power is free, unlike fuel oil or natural gas. It is also a unique method of generating hot water for sanitary purposes throughout the year, without radiating any carbon dioxide.

How Does a Homemade Solar Water Heater Work?


As previously mentioned, a solar water heater works by captivating light. Fundamentally, the light is captured through a collector positioned on the roof, which transforms the sun’s energy into heat.

From there, the heat is transmitted to the water tank via the circulating pump. The regulator prompts this exchange; however, this happens only when the solar collector is hotter than the water inside the tank.

As a result, it keeps the circulating pump from utilizing electricity needlessly. Indeed, it also impedes overheating. During summer, when the skies are bright, you can obtain the collector’s highest efficiency in the middle of the day.

Also, solar water heaters work excellently when the solar water heating collector faces the south.

On the other hand, in conditions when there’s no adequate sunlight, your water is preheated, and a backup system kicks in to bring your water to the needed temperature.

With this, you ultimately utilize solar water heating systems to generate warm water at a steady temperature throughout the year without giving off any carbon dioxide.

Essentially, a solar hot water system is typically specified according to the circulating system and type of connector it utilizes.

The Materials Needed to Build a DIY Solar Hot Water Heater

Screwdriver Set: The set must include diverse types of screwdrivers, such as the cross, torx, slow, etc. The screwdriver is a lot easier and quicker to utilize with an electric drill.

Copper Tubing Cutter: You use this when cutting the copper tubes. To use this, you need to hold the copper tubing and fasten the cutter around the pipe you need to cut. Then, twist the cutter around the pipe to tighten the knob lightly on each turn to intensify the cutting pressure on the pipe.

Drill and Drill Bits: An adjustable drill machine is a great option. Go for the one that is suitable to utilize for metals, plastics, and woods.

Burner and Soldering Equipment: You use this equipment when soldering the copper tubes together. It contains a burner as well as soldering equipment with a soldering paste flux.

Forstner Drill Bits: You utilize this when creating holes in plastics and metals. You can also use these tools to puncture holes in the storage tanks, input and output pipes, etc.

PP–R Pipe Welding Equipment: These tools are dependable to use for water supply plants and in plumbing. Heat is required to cause the pipes to melt.

Right Angle Clamps: These tools are optional; nonetheless, they are pretty helpful in making sharp 90-degree angles without holding it all together using your hands.

Standard Tools: These tools include measuring equipment, plastic and metal hammers, scalpels, meters, wrenches, and various types of clamps, etc.

Saw: Pick the type of saw that works well with metals and wood. A circular electric saw is handy when putting in your preferred angle or when cutting metals.

Silicone Gun : This item is purposely for sealing off a solar heated water collector. You apply it between the wood, metal profile, and solar glass, etc.

Metal Sheets Scissors: These tools are primarily helpful when cutting sheet metals such as aluminum.

Scissors: Take note that you’ll require special scissors adept at cutting pipes, mainly when working with PP-R pipes.

Paintbrushes: You use these tools to add paint to the inner walls of the collector, copper pipes, and absorber plate. Preparing for the steps is essential since you might require more layers before the entire absorber is fully covered.

Copper Pipe Bending Tool: You use this item if the copper tubing in your solar collectors is built with one copper pipe. It is vital to bend the copper pipe in a zigzag pattern.

Likewise, you’ll need to prepare safety equipment. Your safety equipment will be utilized in all steps, specifically when working with banners, drills, and cutting metals using a circular saw.

The materials you need to prepare when working with your DIY solar hot water system include:

  • Insulating material
  • Silicone
  • Treated wooden planks
  • Copper tubes
  • Aluminum sheet
  • Screws for wood and metal
  • Transparent cover glass
  • Various types of rubber seals, adapters, and valves
  • Aluminum L profile
  • Matt glass paint
  • Barrels for hot water storage
  • PP-R pipes
  • Aluminum foil
  • Thread seal paper
  • Check valve
  • Plastic wrap and tape

Steps to Build Your Own Solar Water Heater


If you want to immensely reduce your energy consumption on your domestic hot water system, it might be time for you to go solar. To get started with the process, please refer to the following guides:

Step 1: Design and create a wooden frame for your solar tank.


First and foremost, you need to design and create a wooden frame for your solar tank. To do so, you should bend one side of the box so that the glazing could obtain more ample sun exposure.

Step 2: Create the sides and walls of your solar heater box.


The next step is to construct the sides and walls of your solar heater box using plywood. You need to cover the inside of the box with materials such as fiberglass insulation, aluminum, or Styrofoam.

Step 3: Determine where you will set up the plumbing.

In this step, it’s important to point out where you will set up the plumbing. Moreover, it would be best to determine where the appropriate opening for incoming water and exiting pipes will be situated.

Please note that it is necessary to know how to connect your solar water heating system and house plumbing.

Step 4: Insulate the pipes.


Since it is crucial to ensure the efficiency of your DIY solar water heating system, it’s necessary to insulate the pipes to minimize energy loss.

Step 5: Cover the box.

There are a few options when covering the box, which is helpful for glazings like acrylic, tempered glass, and fiberglass. Chiefly, the bottom line here is to intensify the sun’s heat through the cover and significantly lessen heat loss synchronously.

It’s worth noting that tempered glass is a well-known alternative because of its suitable attributes for this purpose.

Step 6: Figure out the efficiency of your solar water system.

Lastly, removing the external enclosure, insulation, and old pipe fittings is crucial if you’re utilizing an old electric heater. Furthermore, you need to inspect the inside for any residues.

Clean the tank, if needed. Meanwhile, to intensify heat absorption, it is vital to paint your tank in flat black. In this final step, you will also have to set up the pipe fittings, drain, and pressure release valve.

Check all the exposed surfaces. Apply silicone along the connections as well as joints. Set up the connectors to focus the sun’s rays, including the shutter or insulation above to ensure adequate heat loss protection. Then, you’re all set to use your solar water heater.

Meanwhile, should you wish to check out a sample of how to make a solar water heater, you may consider watching this video:

Is It Possible to Plug My Solar Water Heater Into a Hot Water Heater?

Yes. You can plug solar hot water systems into hot water heater tanks. Primarily, it’s essential to set up this system if you want additional hot water; it works by transmitting the cold water from the water heater tank.

Please note that this works more outstandingly in warm climates since heat is likely to radiate from the pipes when it’s chilly outside.

Is it okay to plug the solar hot water systems into the primary heating systems?

Yes. As you might already know, a homemade solar water heater utilizes sunlight to heat water in a panel, commonly installed on the roof.

It would produce electricity that could be utilized to run the solar heating pump.

What Are the Benefits of Installing a Solar Water Heater?

One of the most effective methods to reduce expensive energy costs due to water heating is to have a solar water heater installed.

Substantially, solar water heaters won’t merely lessen your monthly energy bills, but they will also provide several perks in a more cost-effective approach.

Here are some of the perks of installing DIY solar water heaters:

Works more efficiently

Solar water heaters can warm up to 80% of your annual water without the need to utilize external fuels.

Hence, it’s not surprising why they are unbeatable when heating water more efficiently than other forms of energy.

Zero Cost

Since solar panels primarily utilize the sun’s energy, this implies that it’s unnecessary to spend lavishly on the power grid for utilizing electricity. You can delight in completely free energy that’s available every day, so you can significantly save money.

The only thing you need to do is determine how to adjust your solar panels to maximize their performance during overcast days. It’s best to contact professional solar water heater suppliers to uncover how your heat pump water heater can be more efficient in different seasons.


Unquestionably, there’s no greener energy than solar panels. They don’t rely on fuels to operate; they can guarantee zero-emission, and using them decreases our carbon footprint in the environment.

Affordable Setup Process

You will spend considerably less on setting up a solar thermal system than a PV system.

Helps You Save More Space

If space is what you are worried about, rest assured that you can ditch that issue. If the space is not sufficient, you can opt for a thermal panel.

Does not require maximum maintenance

Solar-powered water heaters merely call for low maintenance. They only require simple and regular cleaning. Since solar systems do not come with any moving components, regular repairs are less likely to happen.

What Is a Batch Solar Water Heater?

A batch water heater is the simplest kind of thermal collector that uses solar energy. The water is made hot in batches, hence the name.

Because batch heaters require no pumps, they make for a great DIY choice. This type of passive water heaters also needs little maintenance and will suit small families with up to 4 members.

The Bottom Line

A homemade solar water heater is an excellent means to reduce energy bills associated with heating your water at home. When you utilize solar energy, the sun’s power is utilized to heat water. It’s kept in a hot water tank, and you use it when it’s winter or cold outside.

Aside from saving money by building a solar water heater, you can also reduce your carbon footprint on our planet. Hopefully, the tutorials we have shared about building your DIY solar water heating system can help you benefit from solar energy.

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