Originally Posted by Jerry
I have have tried the Harbor freight scope but it is not long enough. I filled it the other day with the city tank valve and it belched air through the tank fill. So it is not completely blocked. Before filling I put my scope in as far as it would go and there was still water in the tube that goes to the tank.
Now I am wondering if there is a one way valve that would let water in and not come out. And could it be in reversed ??
I have never heard of a valve in the gravity fill tube for the fresh water tank. If there is, it should be identified in the owners manual.
Since you see water in the fill tube before it reaches the tank, then it really seems like the fill tube is blocked. Although I can't explain why there would be air coming out, but not allowing the water to at least slowly drain through a partially blocked tube.
Some RV's have a small air release tube in addition to the large gravity fill tube. If you have the air release tube, you will see a small (about 1/2" to 3/4") hole inside the door to the gravity fill tube.