I'm replacing our water heater.
I disconnected the cold intake and hot out-take. I'm replacing the valve on the cold intake.
I got to the point where I had both the cold in and hot out disconnected, and a new valve on the cold intake (so I can turn it off and restore at least cold water to the house).
Here's my huge problem:
If I leave the cold water intake valve open and turn on the water to the house again, cold water comes pouring out of the cold intake pipe as you'd expect.
If I then close the cold water intake, water then starts coming out of my hot water out take!?
If not, what could be going on here?
I'm trying to run this through in my head and I can't think of any situation where the hot water lines would be connected to the cold water lines...except possibly at a mixing valve somewhere? One of the showers, perhaps?
If that's the case, is there any harm in letting it be? Or am I looking at some major plumbing tear-outs to figure out why this is happening?