Hey all, thanks for the forum!
The background: We have a System 2000 boiler which was installed in 2007. One problem I've been having with it because of our hard water is the plate heat exchanger clogging. I purchased an extra one, and have to swap every 8 months, and clean out the old one with Sizzle.
Recently I had to shut the residential water off, due to a shower valve behind the wall that corroded and sprung a leak. We had the water off for 3 days. On the third day, my wife called me in a panic - the boiler was making a loud grating noise, and before I could get home, started exhausting steam/hot water out the relief valve. Of course, I had her shut it off. When I turned it back on, it started loud sloshing, banging and the outgoing h20 temp went up to 270F! (I thought the system burner 2000 would shut off before going that high!)--anyway, i guessed the boiler was airlocked, so i purged and bled the whole thing. It worked fine after, and was quiet again. We had the same problem again after another day, and i realized there might be a leak (nothing visible anywhere that I could see though). Due to the fact that the residential was off, the make up water system was not supplying H20 and therefore the air lock. I fixed the shower valve and pressured the system, no more problem for about a week. Problem is back, and I suspected a leak in the exchanger, with boiler water escaping into our residential, therefore invisible. Maybe the numerous times i cleaned the exchanger with sizzle was too hard on it?
Has anybody ever heard of something like this, and the long range question would be, water softener or go indirect Hot water instead of plate exhanger? I'm done with cleaning them out every 8 months.
Thanks for any insight anyone may have,