Hi all,
The plumber came back, did a thorough flush of the house (did not do that the first time) - this involved taking off all the aerators, mixer valve in the basement, filter off of the tankless hot water heater, hooking up hoses to flush them outside the house. Of course there were those black flakes stuck in all of those areas, like a lot. He said we might still be seeing them for awhile until they all clear out of any other leftover areas. But I'm going to go mad if I see them anymore. I can't imagine where else they could still be stuck throughout the house at this point.
He checked the house pressure, it's 78psi. He matched the new thermal expansion tank to that. The new one did not appear to be ruptured, judging by the fact that no water leaked out when the air valve was opened.
Now I've had some time to think about it. He said he's never seen a thermal expansion tank do this before. I'm curious if it was really the thermal expansion tank. Here's what I was thinking:
Yes it was the thermal expansion tank
1. The smeary particles seem rubbery - that could have been the ruptured bladder. The metallic pieces could have been the inside lining that corroded off.
2. The old tank was absolutely filled with these particles when we took it off.
3. There's really nothing else in the hot water side of the house - the tankless heater was replaced, there are just two small pumps that haven't been replaced. The house has a filter on the water main, doesn't have anything like this in there.
It was something else (problem is still lurking)
1. The plumber said he's never seen a thermal expansion tank do this.
2. I'm not sure if a ruptured bladder would break apart into all these tiny pieces?
3. Would the inside of a thermal expansion tank start corroding off into tiny metallic pieces as well? (we had those tested by a lab, they said they were copper).
4. Reading up on this, it seems like ruptured tanks will leak water out the bottom air valve when opened. The old tank did not leak water, just air.
@Caduceus I know you said you worked at a company where a bunch of these failed - did they fail in this manner of the particles coming out?
I tried contacting the manufacturer (Amtrol), but they haven't replied.
Thanks all