Toilet leaks when water heater heats

[truckman]

Has anyone experienced this mysterious phenomenon? The toilet valve leaks every time the water heater nears the end of the heating cycle. I have determined that the toilet was not erroneously connected to the hot water. I am at a loss as to what would fix this. Apparently the water heater is somehow causing back pressure in the cold water line.

Cougar 318 SAB

[Ron]

As your water heater heats up it builds pressure as the water expands and no where to go in a closed system as in your trailer. You need an air gap in the system to cure the problem. Shut any incomming water off to tt, open relief valve on wh and let water drain until stops, close relief valve and then turn water back on and you should be good to go. You probably have a weak seal at the toilet supply that is the weakest point when water pressure builds up. Hope this helps, Happy Campin...........Ron

[hankpage]

X2 .... If that does not work the check valve in the water heater may be bad or clogged.