Plugged Tankless Coil

Rich_L

I have two Ruud tankless domestic water heater in a building I just inherited to take care of. The two units are piped in parallel. I've found one of the units to have a completely plugged coil. I get absolutely no flow, even with city pressure against it. I've tried pumping cleaning solution through it, from both directions, but with no flow I can't get anywhere. Can this unit be saved? So far I've tried DHW Tankless cleaner and ice machine cleaner. I've been trying to get flow with cleaning solution for over a week now. Thanks

Leon82

Remove the heat exchanger and soak in vinagar or heavier chemical for a few days?

kcopp

The HX is pretty thin in most of those units. Instead of going through all this "cleaning" I would just replace the HX.
Then find out why it did that and take action so it does not happen again.
They do make siliphos filters that allow the calcium to not stick to the piping.

http://www.aquapurefilters.com/store/product/200106.200095/ap430ss.html

Jamie Hall

@kcopp has an excellent point. If it's that badly plugged, the odds of its leaking when you get the scale out of it are close to 100%.

Rich_L

Thanks for the responses. I didn't know if possibly anyone else had such experiences with these units. I believe what led to this is simply lack of attention/ maintenance. When I asked what kind of schedule they had for descaling their tankless water heaters I was met with a puzzled glare... This unit is almost six years old and has never been de-scaled! Thanks again

Big Ed_4

Thinking past your fixed solution ....Is it piped reverse return ?