cold water feeding into hot water supply

[traff_ss]

Yesterday, I replaced a gas water heater. Everything went okay, except I noticed something weird. After shutting off the gas and the cold water supply into the tank, I hooked up a drain hose and started draining the tank. I then unattached the hot water line (output) to help the tank drain quicker, and put a bucket under the line since I have a two-story house and I figured there would be water in the line.

To my surprise, there was A LOT of water, under pressure, coming out of the hot water line. In fact, I had to run out and shut off the main before I filled the bucket. Obviously, cold water is feeding into the hot water circuit at some point. I have an old house, but all of my fixtures are pretty new (most in the past two years).

I tried an experiment: I went around the house and shut off all fixture cut-offs...hot and cold, for all sinks, toilets, washer, etc. The only one I could not shut off was the upstairs shower (there is no cut-off). I turned the main back on, and I still had a steady stream of cold water coming out of the hot water line.

Anyone ever see this? Any ideas on how to fix?

thanks,
tom

[Dunbar Plumbing]

If you did not have any problems with this reversal of flow before.....more than likely the hot/cold lines are reversed into the tank and someone moved the dip tube to the hot outlet side. Common in the older homes when a loop was installed backwards to test off the water lines.

Might just have to jot the pipes around to make the new one, right.