Fresh Tank Fill When Hooked To City Water

Do you have a fill valve and a gravity fill? If so valve is not closed tight. Look in compartment for water connection for valve.
Pump or back flow preventer leaking back into tank. Make and model of pump?

Thanks for the reply Bud,

No fill valve just a connection for the city water and a separate gravity fill tube.

Shurflo, but not sure of the model. I believe the 8000 series. Simple low dollar pump.

Thanks
Jeepman71

Sounds like your only check valve is in the pump. You can add a check valve just above stream of the pump, or replace pump. The pump should be good on a 14 model, so I'd go with adding one to line.

Jerry

Thanks for the reply Jerry,

I have found some trouble shooting info on line and that does appear to be the problem. The pump works well so you might have the best answer. The trouble shooting did comment that it might be a dirty check valve. This is the second outing this spring but the first for full hook ups. I might try it again after running the pump for the weekend. Don't think it will work because we ran the pump the entire weekend a couple of weeks ago.

The pump acts as the check valve in many models. A small piece of debris would cause your issue. Simple to open pump end of assembly to check for debris.

My simple water flow setup is like what is shown here... I do have a one way valve between the water pump and the fresh water tank. My water pump also has one built-in I think...

Like said above you can add one of those one way valves like shown here. LOWES has them in the plumbing section...


Google Image

Some of the more fancy units has a fresh water tank fill setup from the city water port... Mine does not...

Roy Ken

Shurflo pumps have an internal check valve ----single diaphragm tp prevent backflow thru pump

High city water pressure/
Debris...plastic from installation/
Scale/crud on diaphragm

Running pump/using fresh water from tank will typically clear up debris/crud
Using a quality water pressure regulator solves high pressure issue

An in-line check valve --- 1/2" barbed type---can be installed in pump suction line as additional preventer

Try just running pump.
If check valve does not clear up/seal when pump is off then pump will occasionally cycle on/off due to pressure decrease from leaky check valve




I quit using 'city water' connection 9 yrs ago due to major unknown leak while sleeping ($6000)
Since then pump only....fill tank/use pump
If any leaks pump cycles and you know it
Plus very easy to turn pump OFF when going outside/leaving RV/sleeping etc. then having to go to water supply hose bibb to valve it out.

Pump/Tank for US!