Cleaning a Tankless Water Heater

I ran across a post somewhere else that talked about how to clean "or descale" a tankless water heater, which i've never had until here. Recommended running vinegar thru the system.

Do you clean your Tankless Water Heater ?? How often ?? What do you use ?? Any net info you recommend ??

 

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.

 

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.

 

Using this old post for an update.. Checked out some youtubes on cleaning a tankless water heater, both recommended vinegar and a small recirc pump. With our new pressure system (fantastic), the old wtr heater is still running weaker than the new ones, so this is my next step. DOES ANYONE HAVE A "CLEANING KIT" (5 gal bucket, small pump (fish pond?), and hoses they would loan me (will contribute to your cost)).. Or know where i can rent one ???

 

My old Water Heater is running very slow, much more so than the other two newer ones in the house. I'd like to try to clean out the hard water scale by running vinegar through it but i can't find anyone with a bucket/ pump/ hoses set up who will post the existence here or agree to loan it (i'd give a deposit so i'll return it in working condition)...... Maybe it's easier to throw it out and get a new one, it's been installed for many years and i doubt it's ever been "descaled". If it's not a scale problem, then it needs replacement anyway... ?????????..

 

@Edward K
Couldn't you just fill the heater with vinegar and let it sit for a few hours (days)?
If the heater is very large you could dilute Muriatic acid and use that (it's cheap).
Before using muriatic acid you should get some advise from someone with a chemistry background. There is probably someone around here that would know a suitable concentration.

 

My ex used Muriatic acid on the sink faucet. It started the faucet rusting and, even though she only did it the one time, it got worse and worse until we had to replace it within the year. It was not the faucet as we have an identical one on the CR sink downstairs and no problem with rust.

I would not use it. What you need is CLR. Sometimes you can find it, or a generic version of it, at the American Import store in Daro, across from the organic market. But it is seldom there so you may have to ask them to text you when they get some. Also, the stuff they get is a very weak solution so you would have to leave it sit in there for a few days to do any good. But at least its not toxic like Muriatic.