Water check valve problem?

[jepetto58]

Hello all, I am a new owner of an '83 FC35. I have been going through some of
the systems on the bus, cleaning and learning a lot. After doing searches on
this forum to solve my problem, I still am confused.
The problem I am experiencing is with the water filling and pumping. The water
pump seemed to be working fine until the fresh water tank emptied. I recognized
it was empty right away and filled tank. ( water was coming out of overflow}
Pressure seemed fine for the rest of the evening while using the kitchen sink.
The next day when I tried to use the sink, the pressure from the pump was very
low and no water at all when I turned to the hot water. Pump runs continously. I
disconnected the inlet hose to the Flojet pump thinking maybe airlock-lost
prime, while it was running but that didnt change anything.
Also, I thought I would give a try at using "direct water hookup",(city water),
which gives me hot water and good pressure but it is pouring out the overflow of
fresh water tank while hooked up. Is this where the check valve is bad? What
does it look like? I have the area under the bed open but there are a lot valves
there. I recognize a pressure regulator but this is all new to me. Thanks in
advance for any suggestions or help.
Jeff Lawrence
Panama City Beach,FL.
850-527-1085