Originally Posted by Paul S.
What if your system is charged and then you disconnect it. Then you try to flush the toilet. With any pressure left in the system and 10 gallons of water in the heater I think the heater will back feed the cold side and push any sediment to the open valve. Does this make sense???
Certainly plausible. I don't think it would make it to the toilet in that flush, but it could put debris far enough down the cold line to get past a joint which could then travel down the cold line during subsequent flushes under pressure.