How to Check If Solar Hot Water is Working


To do so, start by observing the pump’s operation and the water temperature in your storage tank.

Ensuring your solar hot water system operates effectively is essential for both cost savings and environmental benefits. Regular checks can help you identify potential issues before they become major problems. With this guide, you’ll learn how to check if solar hot water is working efficiently.

How to Check if Solar Hot Water is Working

If you’re unsure about the functionality of your solar hot water system, fret not. Here’s a comprehensive step-by-step guide on how to check if solar hot water is working or not:

1. Locate Your Solar Hot Water System

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Begin by identifying the placement of your solar hot water system. Typically, solar panels are installed on the roof, while the storage tank is situated at ground level, often concealed within a protective cabinet or casing. If you’re unable to locate your system in a practical location, it may be installed underground, requiring you to contact your installer for further guidance.

2. Start by Checking the Pump

Verifying the pump’s operation is a simple process. Locate the pressure gauge on your system and observe if the needle is in motion. If the needle moves, it indicates that the pump is functioning correctly. However, if the needle remains stationary, this suggests a malfunctioning pump, and this information will aid in diagnosing any issues in subsequent steps.

3. Inspect Insulation on Your Pipes and Fittings

Thoroughly examine the insulation on your pipes and fittings as it is critical for the proper functioning of solar hot water systems, which rely on heat transfer. Any gaps or cracks in the insulation can lead to heat loss and reduced system efficiency. Detect insulation issues by identifying cold spots, and promptly seek the assistance of a reputable plumber to rectify them. If all appears well, proceed to the next step.

4. Ensure There is No Air Trapped in the System

How to Check if Solar Hot Water is Working 1

One common problem with solar hot water systems is the entrapment of air, often resulting from installation issues. The air within the system disrupts heat transfer, diminishing system efficiency. To check for air, locate the pressure relief valve, typically situated near the storage tank. Open the valve and observe if air escapes. If water emerges from the valve, it signifies the absence of air in the system. Conversely, if no air escapes, it may be advisable to contact a local plumber.

Also Read: How to Connect Solar Panel to Water Pump

5. Inspect Collector for Debris

Solar panels, being typically located on the roof, are susceptible to accumulating dirt, dust, leaves, or bird droppings over time, obstructing sunlight from reaching the collector cells and converting it into energy. Safely inspect your solar panels by carefully ascending to your roof. Employ a ladder with caution and have a ground spotter for support.

Clean the panels using a soft cloth and soapy water, ensuring thorough rinsing. Dry with a clean cloth. While on the roof, assess the warmth of the solar panels (on a sunny day). If they remain cool to the touch, this suggests inadequate heat absorption and a potentially more complex issue.

6. Verify All Valves and Taps are Open

For persistent issues with your solar hot water system, inspect the valves and taps. Closed valves can impede water flow, compromising system efficiency. Test each valve by toggling them on and off to ensure they’re not stuck. Additionally, there are usually two taps—one for the cold water supply and one for the hot water outlet—both should be fully open.

7. Activate Pump and Monitor Water Heating

How to Check if Solar Hot Water is Working 2

After completing the aforementioned steps, initiate the pump and wait for the water to reach a warm temperature. If these steps fail to yield warm water for your household, it’s advisable to contact trained professionals who can provide efficient and reliable repairs. This explains how to check if solar hot water is working or not.

Also See: Does a Solar Water Heater Work at Night?

How to Remove Air from Solar Water Heater

After learning how to check if solar hot water is working, let’s see how to remove air from a solar water heater. To enhance the efficiency and performance of your solar water heater, it’s essential to eliminate any trapped air. The steps to do so are as follows:

Step 1: Switch Off the Solar Water Heater Power:

It’s crucial to turn off the power supply before performing any maintenance on your solar water heater. This precaution ensures safety during the process.

You might also be interested to know How to Turn Off a Solar Hot Water System. So, check out this link.

Step 2: Locate Air Release Valve:

Most solar water heaters are equipped with an air release valve positioned on the top of the unit. This valve allows you to purge air from the system.

Step 3: Open Air Release Valve:

Using a suitable tool, carefully open the air release valve. Have a container ready to capture any water or air discharged from the valve.

Step 4: Monitor Air Release Valve:

As you open the valve, you’ll notice water and air bubbles escaping from the system. Keep the valve open until a steady stream of water flows out. The duration may vary depending on the volume of trapped air.

Additionally, check out What is Solar Hot Water Rebate Australia Programe?

Step 5: Close the Air Release Valve:

After all the air has been purged from the system, securely close the air release valve. Be gentle to avoid any potential damage to the system.

Step 6: Restore Power to the Solar Water Heater:

Once the air release valve is closed, reactivate the power supply to your solar water heater. Allow the system a few minutes to warm up and start producing hot water.

Step 7: Monitor Solar Water Heater:

After turning on the power supply, keep a close eye on the solar water heater to ensure it operates correctly. Check the temperature, water pressure, and hot water output to confirm the system’s proper functioning.

It’s essential to remember that if you’re uncomfortable performing these tasks on your own, it’s advisable to seek professional assistance for solar water heater repairs. Solar water heaters are intricate systems that require specialized knowledge and skills to ensure safe and efficient operation. Now that you know how to check if solar hot water is working and how to remove air from a solar water heater, the only thing that’s left to address is how to service a solar hot water system.

Also Read: Solar Underfloor Heating Guide: Everything You Need to Know

How to Service Solar Hot Water System

Solar energy systems, like any technology, require regular inspections and maintenance to ensure they continue operating efficiently. Additionally, components may occasionally require repair or replacement. Preventing scaling, corrosion, and freezing is essential for their longevity and performance.

You may be able to perform some inspections and maintenance tasks yourself, but others require a qualified technician. Tasks involving climbing ladders, roof access, soldering, or tree limb removal should be handled by professionals for safety reasons. Always request a written cost estimate before authorizing any work. In cases of extensive damage, replacing, shutting off, or removing the solar system may be more cost-effective than repairs. The following points explain how to service solar hot water systems:

1. Periodic Inspection Checklist

Solar water heater

Here are suggested inspections for various components of your solar system. Consult your owner’s manual for a maintenance schedule and keep a record of past maintenance activities to manage preventative maintenance intervals and identify any recurring issues.

A. Collector Shading: Periodically check for shading on the collectors throughout the day (mid-morning, noon, and mid-afternoon). Shading from vegetation growth or new nearby construction can significantly impact collector performance.

B. Collector Soiling: Dust or dirt accumulation on collectors can reduce their efficiency. In areas with specific soiling sources, such as bird droppings or plowing dust, periodic cleaning may be necessary.

C. Collector Glazing and Seals: Inspect collector glazing for cracks and ensure that seals are in good condition. If the plastic glazing becomes excessively yellowed, consider a replacement.

D. Plumbing, Ductwork, and Wiring Connections: Look for fluid leaks at pipe connections, and check duct connections and seals. Ensure all wiring connections are secure.

E. Piping, Duct, and Wiring Insulation: Verify that all valves are in the correct operating position. Check insulation covering pipes, ducts, and wiring for damage or degradation, and replace if necessary. Protect wiring within conduits.

F. Roof Penetrations: Maintain flashing and sealant around roof penetrations as needed. Keep an eye out for any signs of water leakage on the underside of the roof if visible.

G. Support Structures: Examine all nuts and bolts securing the collectors to support structures for tightness. Watch for corrosion on steel parts and perform cleaning and painting if necessary.

H. Pressure Relief Valve (on liquid solar heating collectors): Actuate the lever to ensure the valve is not stuck open or closed.

I. Dampers (in solar air heating systems): If feasible, check that dampers open and close properly and are in the correct position.

J. Pumps or Blowers: Verify the operation of pumps or blowers (fans). Listen for their activation when sunlight hits the collectors after mid-morning. If you can’t hear the pump or blower, it may indicate a malfunction, often due to a faulty starting capacitor.

K. Controls: Inspect solar water heating controls, including temperature sensors on the collector outlet and at the bottom of the storage tank. Ensure proper operation of the delta-T controller. If issues arise, check for sensor short circuits or open circuits.

L. Heat Transfer Fluids: Propylene glycol antifreeze solutions in liquid (hydronic) solar heating collectors require periodic replacement. Measure pH (acidity) and freeze point and replace if they deviate from specifications. It’s advisable to involve a qualified technician for this task. For systems using water with a high mineral content, consider descaling solutions to remove mineral buildup every few years.

M. Storage Systems: Examine storage tanks for cracks, leaks, rust, or corrosion signs. Steel storage tanks may have a sacrificial anode that should be replaced according to the supplier’s recommendation. Periodically flush storage tanks to remove sediment.

Also Read: 4 Advantages Of Solar Water Heater

2. Preventing Scaling and Corrosion


Two major factors affecting solar hot water system performance are scaling (in liquid systems) and corrosion (in hydronic and air systems).

  • Scaling: Hard water with high mineral content can lead to calcium deposits on heat transfer surfaces. Regular descaling or the use of water softeners can mitigate scaling. Use vinegar or mild acidic solutions to clean heat exchangers periodically.
  • Corrosion: Galvanic corrosion can occur when dissimilar metals come into contact, typically due to improper connections. Prevent this by using bi-metallic connectors with plastic sleeves. Oxygen entering open-loop hydronic solar systems can cause rust; use corrosion-resistant components.

3. Freeze Protection

Solar water heating systems using liquids as heat transfer fluids need protection from freezing in cold climates. Options include using antifreeze solutions or draining the system when temperatures drop below freezing. Always follow manufacturer recommendations for freeze protection.

Remember that regular maintenance and addressing issues promptly can extend the life and efficiency of your solar hot water system.

Cross-Reference: Troubleshooting Your Solar Water Heating System

Incorporating a solar hot water system into your home is a smart choice for energy efficiency. Checking and maintaining it regularly ensures it provides reliable, eco-friendly hot water. By following the above-mentioned steps, you can rest assured that your solar hot water system is working efficiently, reducing your energy bills.

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