There is a little bit a back flow from the water heater into the supply side. I, momentarily, get hot water out of the cold water faucet. Is there any reason that I should not install a check valve on the supply side of the water heater?
A friend of mine just went through this on his home water heater. More than likely it is a faulty washer on the faucet. That turned out to be his problem - after he had tried all the more complicated things he could think of. To the best of my knowledge, a check valve on the supply side is not a problem, but it might not solve the problem either.
