City water diverter valve leaking / replacement

[ok-rver]

after a week in Brownsville TX  connected to 50 psi city water, we came home one afternoon to a lot of water under the MH. Found the fresh water tank overflow just in front of passenger side rear wheels flowing a trickle of water. shut off city water and ran off tank for a few days. would then alternate between tank and city connect. When traveling and not connected to city water, I have had to switch valve to fill tank position to keep pump from back flowing thru inlet port.

Pulled diverter valve out from behind water bay panel. Disassembled valve and ball was crusted with calcium. Teflon seats looked ok. Found a tube that fit tightly into the port of the valve ball, spun with drill and polished with brasso and then Fritz. Looked really good. There is a check valve in one of the outlets to the valve. There was a BB size chunk of something that would hold the check off the seat. reassembled and had good resistance from seats. screwed PVC cap onto one of the outlets. connected hose to inlet and pressurized at the house. Turns out the seats were not as good as I thought. pretty good trickle. Called Watts and 2004 era valves no longer have replacement parts and the next generation valve is not available. all the brass valves I could find were out of stock. purchased a SS valve of a little different configuration for $60 delivered.   installed and it is not leaking off the pump. the valve mounts differently and came home to make a new mounting plate. have not moved MH to water faucet to check fill from hose.

I can not find were any one else was having similar problems.

[Bob Jones]

I had/have a similar issue. Water tank was self-filling. There's two common things that cause it, the check valve in the electric water pump is leaking/bypassing or the city/water valve is leaking. The check valve in my pump was fine. Regardless, I have a spare pump and replaced it. Still filling itself. So then I replaced the city/water valve with the one that was on the bypass for the hot water tank (same valve). Still leaked. OK, so I bought a new city/water valve and installed it. Same thing. 

After all that work, sometimes it leaks, sometimes it doesn't. So now when the tank is full I just shut off the water from the pedestal and wait for the fresh tank to get down to the bottom before turning the city water back on and let it self-fill over a few days. 

Wish I could give you an answer that actually worked. 

Edited April 13, 2022 by Bob Jones

[Bob Jones]

So...be sure to check the check valve in the electric water pump because that can also cause a self-filling water tank.