Water Heaters

Solar Water Heater is Not Heating: 6 Common Issues

Written by Chris

Solar Water Heaters are an essential component in the house. They provide a constant supply of hot water for cooking and cleaning purposes. There are times when the efficiency of the solar water heater turns zero. A question arises, “why is my solar water heater not heating?” sinks in the owner’s mind. The fact is that there is a pool of reasons behind the not functioning of the solar water heater.

This article lists five common problems with a solar water heater. You can check these problems to know why my solar water heater, is not heating.

What is a Solar Water Heater, and how does it work?

Solar Water Heater provides a constant supply of hot water. It uses the sun or rather solar energy to perform its heating duty. A thermal collector is used in gathering solar energy to be used in the heating process. Solar water heaters are mostly used for residential and industrial applications. The system circulates water to the collection where heating takes place. Fluid in the collector gets heated, after which the energy is transmitted to water. To be noted, the thermal fluid must be a non-freezing fluid. A system’s efficiency is the most promising factor that every owner dreams of, but this is not always the case.

5 Common reasons why a Solar Water Heater isn’t heating

Reason 1: Wrong Setting

There are many reasons for your question, “Why is my solar water heater, not heating.” Among the issues that come in to deter the effectiveness of the system is the wrong setting. Generally, when any system is set in a way not correctly done, the effectiveness can never be 100%. The same happens when a solar water heater is not perfectly fitted following the best setting. The modern solar heater of water has digital controllers; they regulate the electrical booster and what temperature is heated. The electrical booster will perform best when the heat coming from the sun is not enough. When the controllers are not well fitted in the best alignment, water heating will not be in the required time. First, a solar water heater is expected to give hot water on cold days. The outcome can be the opposite when the alignment is not good.

Reason 2: Wastage of Hot Water

A second answer to “why my solar water heater is not heating?” relates to the wastage of hot water. It is important to note that there is an equal amount of cold water that comes when there is water out of the system. For this reason, when the domestic workers are using hot water for other purposes apart from bathing, there is a waste of hot water. After the water is heated, it is stored in an insulated tank to avoid heat loss and limited storage capacity. Hot water needs to be used sparingly. To control this, monitoring the usage of hot water is the best remedy.

Reason 3: Incorrect Installation

Another reason for the failure of heating can be resulting in the wrong installation. There are specified parameters that ought to be followed at any time the installation of a solar water heater is done. An example is considering the maximum height required between the panels and the top tank. Not following these specific measures can fail the whole water heating system. Poor connectivity of pipes can result in low heating or no heating at all for the solar, leaving the electric booster to be the only one functioning. The distance to be covered by water is also too critical to be considered. One way to detect this fault is when some part that comes with the heating system turns out to be waste with no use on installation. It is always good to consider the fact that all parts are useful and none is for decollation.

Reason 4: Wrong Location

A solar water heater can become ineffective when the orientation of the roof and location is wrongly done. The wrong place can be in terms of geographical location or location within the compound. When the installation is done in a shadowed area, there is not enough direct solar radiation. From this perspective, the solar water heater does not receive the optimum solar energy required for optimum performance. Additionally, it includes some geographical areas whose sunshine capacity does not suit a solar water heater’s installation. To explain this, a solar water heater is solely dependent on the conversion of heat energy to electric energy for heating. An area with a deficiency of solar energy will demand other forms of water heating systems that are not dependent on the sun to function. The case can result in the system not working from the installation day.

To avoid this from happening, it is good to include a trained technician who can assess the area’s climatic condition before installation. Smile HVAC experts do a proper inspection of the location before installation.

Reason 5: Excess Dirt

Also, when used for a long time without maintenance, flat collection systems collect dust, which lowers their effectiveness. The cases can result in the blocking of pipes to constrain the flow of water. In turn, the heating purpose of the system yields less than it should. Like any other appliance, a solar water heater requires regular checking to maintain high performance. Cleaning needs to be done by a specialist who must ensure that the heating is off.

Reason 6: Fluid Leakage

Fluid leakage is also another common reason for a solar water heater’s ineffectiveness. This is the most common issue associated with the functionality of heaters. The primary reason for this happening is collector glazing or when pipes are broken. The best suiting solution can be checking and replacing the pipes and broken parts. Lastly, it can also have a loose connection. Reconnection of cables is the best solution for this problem.


Solar water heater effectiveness can be maintained when checking of the system is done regularly. Also, proper installation requires a specialist to consider all the factors necessary for functionality. It is equally important to note that the solar water heater will work correctly in areas with sufficient sunlight.


My solar water heater is not heating. What could be the reason?

There could be several reasons why your solar water heater is not heating. Some of the most common causes include lack of sunlight, a malfunctioning solar collector, a faulty temperature sensor, or a malfunctioning pump.

What should I do if my solar water heater is not heating?

If your solar water heater is not heating, the first step is to check for any obvious issues, such as a lack of sunlight or a malfunctioning pump. If you cannot identify the problem, it is best to call a professional to inspect the system and make repairs.

How do I know if my solar water heater is getting enough sunlight?

You can tell if your solar water heater is getting enough sunlight by checking the temperature of the water in the tank. If the water is not getting hot enough, it is likely that the solar collector is not receiving enough sunlight. You can also check for any obstructions that may be blocking the sun's rays.

Can a faulty temperature sensor cause my solar water heater to not heat properly?

Yes, a faulty temperature sensor can cause your solar water heater to not heat properly. The temperature sensor is responsible for regulating the temperature of the water in the tank, so if it is not functioning correctly, the water may not get hot enough.

How often should I have my solar water heater inspected?

It is recommended that you have your solar water heater inspected by a professional at least once a year to ensure that it is functioning properly. Regular maintenance can help prevent issues from occurring and prolong the life of your system.

What are some common signs that my solar water heater is not functioning properly?

Some common signs that your solar water heater is not functioning properly include a lack of hot water, reduced water pressure, strange noises coming from the system, or leaks around the solar collector or storage tank. If you notice any of these issues, it is best to call a professional to inspect the system.