How to Clean a Tankless Water Heater





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Cleaning a tankless water heater is essential for its optimal performance and longevity. Follow these simple steps to ensure a clean and efficient unit. First, turn off the power supply to the heater by either flipping the breaker switch or unplugging it. Allow the water to cool down for at least 30 minutes before proceeding.

Next, locate the cold water inlet valve and shut it off to prevent any water from flowing into the heater during the cleaning process. Once the water supply is shut off, find the purge port valve and attach a hose to it. Run the hose into a drain or bucket to collect any debris and mineral buildup that will be flushed out. Gradually open the purge port valve to initiate the water flow.

After letting the water flow through the heater for about 10 minutes, close the purge port valve and disconnect the hose. Reopen the cold water inlet valve to restore the water supply to the heater. Check for any leaks or drips around the connections and fix them if necessary. Finally, turn on the power supply and wait for the heater to reach its regular operating temperature.

Regularly cleaning your tankless water heater ensures that it runs smoothly and efficiently, providing you with a steady supply of hot water whenever you need it.


  • Turn off the power supply before cleaning.
  • Flush out the system to remove sediment buildup.
  • Use a descaling solution to remove mineral deposits.
  • Clean the filter screen regularly.
  • Consult the manufacturer’s instructions for specific cleaning guidelines.


  • Do not clean the unit while it is still hot.
  • Do not use harsh chemicals that can damage the components.
  • Do not disassemble the unit unless necessary.
  • Do not use excessive water pressure during flushing.
  • Do not neglect regular maintenance and cleaning.

Step 1

Turn off the water supply to the tankless water heater.

Step 2

Disconnect the power supply to the tankless water heater.

Step 3

Remove the front cover of the tankless water heater.

Step 4

Carefully remove and clean the inlet filter of the tankless water heater.

Step 5

Flush the tankless water heater with distilled white vinegar to remove any mineral buildup.

Final thoughts 💭

Regular maintenance and cleaning of a tankless water heater is essential for its optimal performance and longevity. By following a few simple steps, you can effectively clean your tankless water heater. Begin by turning off the power and shutting off the water supply. Remove the access panel and clean the exchanger with a soft brush and vinegar solution. Flush the system with fresh water to remove any remaining debris. Check the gas or electric connections for any signs of damage or corrosion. Finally, replace the access panel and turn on the power and water supply. By performing regular cleaning and maintenance, you can ensure that your tankless water heater continues to provide a reliable and efficient source of hot water for years to come.

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