Every manufacturer of tankless water heaters recommends regular cleaning and maintenance, and flushing if necessary. Due to the hard water, especially from the well, the heater might develop lime and mineral deposits on heater's elements. Sediment build-up is especially dangerous in narrow water passages as it might clog the element and prevent further normal heating operation.
Why flushing is important
One of the most important elements is the heat exchanger, which has those narrow water passages. Flushing tankless water heaters whose heat exchangers are blocked by the lime scale is very important and must be done before something happens.
If you don't flush the water heater, the heat exchanger can be damaged as not enough water will pass through and cool it down. Any damage which is related to lime scale build-up is not covered by the warranty.
How To Flush Your Tankless Water Heater
As said, flushing tankless water heaters is not complicated, and once done properly you have to reset the fault code by resetting the power. Here are the step by step instructions (I will consider that isolation or service valves are installed):
- Turn the power OFF (electricity and gas) to your tankless heater.
- Close the shutoff valves on hot and cold water lines.
- Use the service (isolation) valve and connect the EZ-Flush system to the cold water line (with included hose). The circulation pump within the EZ-Flush system is used to force the flushing solution through the heater.
- Now connect the heater with the hose, by using another service valve and terminate it to input port of the EZ-Flush.
- Drain hose and pump hose should both be connected to the same EZ-Flush system.
- Open both service valves.
- Run the circulation pump and let the flushing solution go through the unit for one hour approximately.
- Turn the pump OFF.
- Rinse the cleaning solution from the water heater by opening the shutoff valve on the cold water line (close the service valve between the pump and the heater) so it runs through the heater and into the bucket (approximately 5 mins.) After that open the shutoff valve on the unit and close the service valve between the heater and the bucket.
- Disconnect all hoses.
- Recommendation is also to clean the in-line filter.
- Resume the power and run the water heater.
Edited: 8/30/18