hot water in cold water lines

[garrisjd]

I have hot water in my cold lines. But it only happens at times. Some times i can go for several weeks with everything ok, then several months with hot in the cold lines. I know the water is coming from our water heater because i've turned it off and after the water cools, the problem is gone. One thing i can't figure out is when i turn the water inlet off to the hot water heater, the hot water still comes through the cold lines. Without the pressure, shouldn't that stop the hot water from coming through?

The inlet into the hot water heater is always hot to the touch, which i'm assuming means hot water is crossing over somewhere but i don't know where. Or is there a way the hot water heater could be pushing hot back through the cold lines?

I'm at a loss. Any help is appreciated. thx.

 

[phishfood]

Do you have any type of recirculation system or hydronic heating system tied into your water heater?

 

[garrisjd]

no, no recirculation or other system. thanks for giving this some thought.

 

[johnjh2o]

What type shower or tub faucet do you have? Some single lever faucets will mix hot and cold throughout the home if the cartridge goes bad.

John