I have a 2008 Holiday Rambler Savoy TT and I am having an issue with water filling up fresh water tank while connected to city water. This issue has just started happening. I already replaced the pressure check valve on the city water inlet and also the water pump because I thought maybe the internal check valve went bad but no luck. Still have the same issue. This should be a simple fix but can't figure it out for the life of me. Any ideas? Need more info?