City water filling fresh tank

wnjj wrote:

Farmboy666 wrote:

beemerphile1 wrote:
Your pump has a check valve, if that check valve fails the tank can fill by flowing backwards thru the pump.

My tank has a ball valve on it and can not fill unless that valve is open. The check valve in the pump has nothing to do with it. If I'm on city water the tank valve is closed and completely isolated from water system so pump check valve or not it can not fill.

Do you have 2 valves? A valve that selects between city water inlet and tank fill won’t avoid the pump check valve issue. Now if you also have a valve that isolates the pump outlet from the pressurized water system then the check valve wouldn’t matter. I’m not sure why a manufacturer would install such a valve, however since a good pump won’t allow back flow.


In short, there are 2 ways to get water to your tank:
1. The fill port (whether via valve or gravity-fed tube.
2. Backwards through the pump.

Both would need valved off to prevent filling the tank in the event of a failed check valve.

Maybe I’m not following you. Where is the ball valve connected to? Is it a 2-way or just a shut off? Does your tank have 2 hoses connected to it or only 1?

I don't have a gravity fill, I have a city water connection, If I want to fill my tank I open the valve on the line going into my tank. When the tank is full I shut the city water off and turn the pump on. If I want to use city water the valve to tank is closed so if check valve in pump were to fail the water still can't get into the tank because the Valve is closed.