No water pressure

**DELETED** (OP had already narrowed down the problem)

hram wrote:
Thanks everybody. I've removed pump, blew in both sides(one air blows through, other none). I've removed outgoing pump line and constant flow of water (presumably gravity from tank). Still nothing. Not a drop out faucets, nor air being bled from lines. Tank is full as water is coming out overflow. I plugged water inlet, no improvement. I plugged water inlet with air fitting, added compressed air and water comes blasting out overflow in both valve settings (fill tank/city pressure). It appears water inlet valve is not doing its job of closing off to allow sealed pressurized system? As I mentioned, went to RV supply and no replacement for my setup.shy of cutting both lines and adding an inlet valve to each one separately, I'm at a loss. Thanks again for all help/suggestions! Greg

Greg, sorry to hear about your water problems! I'm interested into what is causing this in your coach? Let us know what you find out. Good Luck, Rooster

Thanks everybody. I've removed pump, blew in both sides(one air blows through, other none). I've removed outgoing pump line and constant flow of water (presumably gravity from tank). Still nothing. Not a drop out faucets, nor air being bled from lines. Tank is full as water is coming out overflow. I plugged water inlet, no improvement. I plugged water inlet with air fitting, added compressed air and water comes blasting out overflow in both valve settings (fill tank/city pressure). It appears water inlet valve is not doing its job of closing off to allow sealed pressurized system? As I mentioned, went to RV supply and no replacement for my setup.shy of cutting both lines and adding an inlet valve to each one separately, I'm at a loss. Thanks again for all help/suggestions! Greg

GPWayne wrote:
I would try bleeding the air out of the lines. AKA prime the pump. Most do not self prime too well. (The easy fix)
Then start looking for broken or stuck check valves.

X2. Almost all the pumps need priming. Get some water in that pump and see if it works!

I agree with GPWayne. Make sure there is water through out the system first (including the water heater, which takes forever to fill).

When our check valve failed (at the hose inlet), turning on the water pump forced water out of the hose hook up and the water pump could not get up to pressure. If that is your problem, a temporary solution is to block the hole so the water pump can get up to pressure. We were in the middle of no-where when it happened to us. A sharpie and duct tape solved our problem until we could find the right fitting.

If water continues to flow into the tank after switching to city my guess would be the check valve on the pump may be leaking. Another inexpensive place to look.

I would try bleeding the air out of the lines. AKA prime the pump. Most do not self prime too well. (The easy fix)
Then start looking for broken or stuck check valves.