How to clean solar water heater tubes & panels safely (Step by step)

Your solar water heater will perform optimally if it is cleaned regularly especially is you live in a dusty environment, have any soiling on your heater’s panels or scale buildup depending on the quality of water supply.

In this article, I will share with you how to clean a solar water heater panels and tubes step by step for best heating performance safely.

Safety first

  • Make sure that it is safe for you to clean the solar water heater panels. If cleaning by yourself, it is best to do this for ground-mounted solar panels that are easier to access safely.

Roof-top mounted panels are more difficult to access and clean. You may be able to use a soft-scrubber mounted on a long-pole with a hose.

If unsure or there is risk of falling, accidents or damage to the heater, contact an authorized representative of your solar water’s manufacturer to service your solar water heater.

First, we shall look at how to clean the flat panels then the vacuum tube solar water heater tubes.

How to clean solar water heater flat panels

These should be cleaned of you observe any soiling of the glass and particularly if you leave in a dusty environment, consider cleaning periodically at least once a month.

Should you observe a reduction in your solar water heater’s heating efficiency, inspect your solar heater panels.
They may need cleaning. For more information on what can affect your solar water heater’s efficiency, check this link.

What you need

  • Soapy water – clean plain water with soap
  • Soft cloth gently remove any soiling on the panels ‘glass
  • Water hose pipe to flush water

How to clean

  1. First, confirm that the panel’s glass is cool enough to remove the risk of cracking from sudden contraction of the glass when cooled suddenly. This servicing is best done in the morning or evening.
  2. Using the cloth soaked in a soapy solution, wash the solar panel glass to remove any dirt, grime, leaves.
    Next flush the solar panel glass with water until it is clear using the hose.

How to clean evacuated tube solar water heater tubes

Note: This is a delicate process that risks damage to the tubes or a leaking water if not done with care.

This is a general guide of how to clean the solar tubes.

Always consult the installation and maintenance guide for your solar water heater model on exact steps for your particular model or consult a certified technician to maintain the heater’s warranty.


  • Evacuated tubes can get quite hot. Cleaning the tubes should only be attempted early morning or late in the evening when they are cool.

What you will be cleaning

  • Cleaning the tubes includes cleaning the outside of the tubes to remove any dust or other soiling that may have covered the tubes affecting their ability to heat water.
  • Cleaning the inside of the tubes to remove any scale that affects the tubes heating efficiency.

What you need

  • Soapy water – clean plain water with soap
  • White vinegar solution
  • White cloth to cover the tubes after cleaning
  • Water hose pipe to flush water into the tubes

Evacuated tube collectors should be cleaned about every two years or so depending on the quality of water supply or environment. Solar water heaters in dusty environments for example require more frequent cleaning.

How to clean

  1. Close the inlet valve supplying the water heater with water
  2. Follow your manual on actual steps to remove each of the tubes at a time.
  3. Wipe each tubes exterior with a soft cloth dipped in the soapy solution to remove any dust, pollen or other soiling.
  4. Rise each tube’s exterior to remove the soapy solution.
  5. Gently shake each tube while holding it vertically to loosen any scale that may have built up.
  6. Flush the interior of each tube first with vinegar to dissolve any scale scale.
  7. Next, flush the interior of each tube using a hose pipe to remove any remaining scale.
  8. Place flushed and clean tube in a safe place without risk of breakage. Cover with the white cloth to prevent it from heating up while it is empty
  9. Repeat steps 2 to 6 for each tube.

  10. Fit each of the tubes back carefully and snugly to avoid leaks (follow your heater model instructions).
    Do this while it is cool so that the tubes do not heat up while they are still empty.
  11. After fitting all the tubes, cover them with a white cloth and open the water inlet valve to allow water into the heater.
  12. When the tubes are filled with water, remove the white cloth so that they can receive the sunlight to begin heating the water.

In summary, cleaning of your solar water heater should be done when the panels or tubes are cool to avoid damage from expansion. Cleaning of both the panels and tubes exterior can be done using a soft cloth soaked in a soapy solution to remove any soiling.

Flush with water to remove the soapy solution. Cleaning of the evacuated solar water tubes is more involved, requires checking the heater manual or even consulting a certified technician.

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