Jayco North Point 377. Dry camping tank is filling while on city hookup

[bradsampson]

Just wondering why my dry camping tank would be filling while on city water setup. I double checked my setup and it all seems right, but it continues to fill my holding tank

[Grumpy]

Could be a bad check valve in the pump, or a piece of dirt in the check valve.

[BigJohnD]

What Grumpy said. I also had one that would leak back into the fw tank when it got above 50 psi. Never did it below.

[bradsampson]

I think I got it. I turned all the valves on and off. One of them must have been jammed open a bit. Thanks all