This sounds kind of crazy but is there a vaccum breaker on the water system? We are hooked to city water but the water sometimes stops to the fixtures sometimes and we do not know why. There sometimes is a clunking sound near the water heater area before this happens. We replaced the tank to the water heater last year. The only way hubby can get it going again is to disconnect the city water line and then it is good for awhile...until it happens again.Has anyone got a clue as to what is going on? It is a 2005 Jayco Jayflight 29FBS. Thanks.