Best Posts in Thread: Cleaning a Tankless Water Heater

If you use bleach to clean your water heater, be careful because it is a strong electrolyte. That means even if your water heater is unplugged, if you have metal hoses and you are hanging on to the them when you fill the lines with bleach you may get a static shock. Happened to me until I realized rubber gloves are wise when handling pure bleach.

 

FIXED... Read all the above, then went back to the heater and dug deeper and found a screen inside an on/off fitting. Took that out, cleaned, reinstalled.. So after all my talk about "de-scaling," just cleaning the filter improved the heater to 80% of a new one. Sounds like de-scaling is only useful if you get mold or so, ours doubtfully ever was descaled, certainly hasn't been in two years. Appreciate all the input on here.....

 

I clean my "on-demand" hot water heater on rare occasions due to potential mold or bacteria build up. Since that is what I am trying to kill, I use bleach. The first time I tried it I got bleach all over the place so I am very careful now. I simply disconnect the water supply line and raise it high so I can fill it with bleach and have it gravity feed through the system. When flushed well I find it kills all the green algae that grows around the heater over time. I would not have bothered except for getting bacterial infections on my skin that I could not explain. Cleaning the water heater was part of an overall cleaning to get rid of mold etc. so I cannot be absolutely sure it was needed but I am absolutely sure it did not hurt.