Purchased a house a few months ago. Hot water heater had re-circulate pump connected to bottom of water heater with timer, but appeared not to function, so unplugged and closed valves connecting re-circulate pump to bottom of heater. Noticed that the hot is not as hot as it should be (based on heater setting) and that cold seems to be warm rather than cold. Noticed that when garden sprinklers run in the morning the water heater always turns on. Had three plumbers out and no one could figure out what was going on.

I tried to close valve on water heater, to shut off hot water and found that I had water pressure for both hot and cold. The last plumber confirmed that this confirmed my suspicions that somewhere the hot and cold lines are connected. He told me it could be almost impossible to find and he would just "live with it". Later I noticed a cut out of the drywall in closet that is behind farthest bathroom from heater. I opened drywall and found a ball valve in the open position. I tried closing the ball valve. At first I thought I solved my problem as the hot got as hot as it should be and cold was cold. Then later I realized that this caused the hot and cold to reverse at all fixtures. So hot to toilets etc.

So as you can see a very confusing complicated issue. If anyone has any ideas of what is the problem or what I can do other than trace out every water line in the house, I would be so grateful.

One valve could NOT cause the hot and cold to reverse to all fixtures, but it could turn off the cold feed, and if there IS a cross feed somewhere, then EVERYTHING could become hot. It is not necessarily "impossible" to find, but could be difficult, however a GOOD plumber could figure it out.

Thanks for the reply... I think the reversal is caused by the flow of water through the heater reversing. This could reverse all fixtures hot and cold. I agree a good plumber should be able to fix it, I guess I can't find a good plumber. Very frustrating no one wants to even try...

ask your friends for referrals

anyone should be able to figure it out with enough drywall destruction

no basement?

Does your recirc system have a dedicated return line? A mixer manifold/valve on the water supply lines on that farthest bathroom sink? (it may be bad) Get the Make/Model of the recirc pump and call/internet search for a local mfg. rep. or dealer/service company.
DO NOT PAY ANYBODY TO RIP OUT YOUR DRYWALL TO TRACE PIPES.



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quote; This could reverse all fixtures hot and cold.

I reiterate, you cannot cause complete reversal of ALL the hot and cold by opening, OR closing, a SINGLE valve. At least not unless you have a very unusual piping system and in that case we cannot diagnose it from here.