Tarp method in-place water replacement

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,062
Tucson, AZ
The only other source would be to check your external plumbing. It is a very commonly made mistake by plumbers to attach cheap galvanized steel pipe nipples to make connections through a wall between brass fittings and brass spigots. I found a number of these in my own home. Whenever galvanized pipe is in contact with brass, the galvanized pipe will corrode due to the formation of a galvanic couple. Grounding is not necessary for the corrosion to happen and pipe tape doesn’t prevent it either. It’s a shortcut that is often used because galvanized pipe comes pre-threaded in various lengths (1”, 3”, etc) so its easy to use. It’s a lazy choice and against good plumbing practice but it gets done all the time. Usually a homeowner finds it when the galvanized finally gives way and there’s a huge leak.

Maybe look at your external plumbing and see if it’s ok.