Tankless hot water heaters are a great investment of modern technology for your home – but it’s important to note that these things need cleaning maintenance to keep running in top shape. This is absolutely necessary to keep it running, especially for a long time, simply due to the fact of hard water and scale buildup that happens otherwise it will cause it to burn out. Consider having a tankless unit that lasts 2x longer that you’re able to maintain (not to mention 30% more efficient too) vs. a tank style heater that you’re unable to clean and eventually burns out from buildup on the elements.
It’s recommended to flush and clean your hot water heater at least once a year, and more often if the water in your area/home is particularly hard (two or three times a year). You should definitely make a habit of checking if there is any buildup monthly or every other month so you can know when to clean it accordingly – this keeps it running like new and more importantly makes it LAST. You don’t want to leave it and end up burning it out from mineral build up like a traditional tank heater – with a tankless water heater you have the ability and advantage of being able to clean it regularly so it has a longer life, which is the reason most people buy one in the first place!
The following are general steps to clean and flush your tankless water heater:
- shut off the power/firing source
- turn off the main gas or propane feeding the unit, or if it’s an electric type unit turn off the circuit breaker
- close the water valves that feed into the unit, and close the valves that carry water out into the home – this isolates the unit so it can be cleaned properly
- remove purge port valve caps from the purge valves on each side of the cold and hot water valves – this relieves any built up pressure in the unit
- attach hose lines to the valves that were shut off that run into and out of the unit
- you may need a small pump (a basic sump or pond pump) to pump water into and out of the pump to flush it
- open purge port valves of hot and cold valves
- use 2-3 gallons of straight (undiluted) white vinegar as a cleaning agent, as you run and flush it out it may be full of sediment/debris so you may need to dump your bucket and get more fresh clean vinegar to finish cleaning your tankless heater
- follow instructions in your unit manual for specific instructions for recommended flushing procedure.
- when done, close purge port valves
- take off the hose lines from each valve that was used to clean the unit
- put purge port valve caps back on
- restart unit (refer to manual)
- run a tap in the house to get the hot water going again and the air out of the system