joecal

Garmo, Thanks for the reply. Here's the latest: I ended up closing all the single handle faucets except for one which was stuck and the problem continued. And I closed off the clothes washer too. So I figured it was the hot water heater letting water go backwards into the cold water line or my other shower or one faucet that I couldnt close since the line was stuck. I had a plumber come by and he says it's the handle to the other shower that's causing the problem. I don't know how he determined that since my wife says he didn't turn off the water supply. Possibly he checked the water heater and verified it was ok and the other faucet also must've checked out. What I'd like to know is if he's sure. He didn't give me any more info that that but I wonder if the cartridge may just need to be replaced. He says the entire housing needs to be replaced but again I don't know how he'd know that if he didn't take out the cartridge and check the inside. When my other plumber put a new cartridge into my first shower he felt around inside to make sure it had no cracks or gouged areas. I don't mind paying to have the whole unit replaced if it's really that (big bucks) but If it's only the cartridge I don't want to have to have to replace something that doesnt need replacing. Thank you for your help and suggestions. Joe

joecal

Well, after doing a little research, I went and bought a water pressure gauge with a lazy hand. I installed it on the outside water spigot to see what the pressure was there. It was 122 which is a lot higher than 80 so I guess I need a need regulator. I'll leave it there for 24 hours to see where the lazy hand goes. Then I'll screw it into my hot water heater spigot to check the pressure there. What I'd like someone's opinion on is if my pressure is too high from the outide or if I'm having thermal expansion (from the water heater) could that cause backflow into my cold water line from my water heater and be responsible for my crossover problem? Thank you

nealtw

I doubt it, run your cold water in the shower untill you get hot water there and go feel the pipes at the tank. I would be awlfully surprized if the cold infeed was hot.

joecal

nealtw. Yes, I already did that and it was hot. Matter of fact the cold water line into the hot water heater has been consistently hot. I don't have one of those thermal expansion tanks.

nealtw

I found this discussion, perhaps you will find it informative.
http://ths.gardenweb.com/forums/load/plumbing/msg1101165611579.html