Plumbing Nightmare!

[RyanV]

Allright so my friend just bought a new lake house and i went up there this weekend to install a new water heater becuase the one there did not work. So i go and i turn the valve off that lets the cold water into the heater off. after that i went to turn all the sinks hot water valves on and well i still get a steady flow of water. Now i am guessing that a pipe is crossed somewhere becuase this should not be. The problem is that the entire house is finished so i cannot find the plumbing mistake. What is the next step? I double checked to make sure what my eyes were seeing by cutting the hot water supply open and turning the main water line on. And well cold water began to shoot out of the hot water lead.

I have no idea how to fix this without completly cutting the house. PLEASE HELP!

[drtyhands]

maybe it's only crossed at the heater.cap the hot leave the heater supply open.

since it's new have him contact the builder immediately,don't fuss with it anymore

[PLUMBER RICK]

i would hope that the problem is a "moen" single handle valve with a brass cartridge.

or it could be a another mixing valve or laundry mixing valve.

i would not worry about it until you have the heater installed and up to temperature. then you can test for a real cross with hot and cold water.

rick.

[ericwagner4]

may not be a big deal at all
some fixtures let cold water run through them to the hot side
so, even if you shut off the water heater valve, you'll still get water in the hot water pipe
just shut main off, drain entire system (open all faucets, hose bibs, etc.) replace water heater, close entire system, turn main on, let water heater heat for about 1/2 hour then check all your hot fixtures to make sure they are warm
good luck - hope this helps

[PLUMBER RICK]

may not be a big deal at all
some fixtures let cold water run through them to the hot side
so, even if you shut off the water heater valve, you'll still get water in the hot water pipe
just shut main off, drain entire system (open all faucets, hose bibs, etc.) replace water heater, close entire system, turn main on, let water heater heat for about 1/2 hour then check all your hot fixtures to make sure they are warm
good luck - hope this helps

true, but they have integral spring loaded check valves or balancing spools. they do not have a direct connection between the hot and cold without having a form of a check valve.
still think that a single handle moen valve is a good possibility.

rick.