Water pump losing prime

[pasusan]

Hi guys - we have a 2004 Roadtrek 170 and on our last trip everything was working fine and then the water pump started losing prime after sitting a bit. Replaced the pump as we had an extra. That didn't fix it.

The pump holds pressure - I can turn off the pump and come back hours later turn the pump on and it doesn't run. But when I turn on a faucet the pump runs and runs and has to prime itself.

Is it the water inlet check valve? Is that even connected within the FW tank plumbing and the pump? Seems like that would drain the plumbing after the pump so pressure wouldn't be held.

What do you think?

[<<B-Guy>>]

I would guess likely a leaking suction hose connection or inlet filter connection or bowl.

If that is ruled out, then an internal valve issue within the pump itself.

Just my @0.02!

[pasusan]

Thanks for the response - will be checking all connections within reach.

I thought about that filter bowl as I've heard they sometimes leak - ours is relatively new and it *seems* OK...

[JohnnyFry]

Another possibility is the city water connection. Make sure that the city water and tank fill valves near the city water hook up are closed.

[pasusan]

We got it fixed. Turns out it was the little nut on the winterizing valve. I didn’t have plumbers tape on it. Put some on and no more leak backs.
Thanks for the help.