Last week I spent one night at an RV park. The fresh water tank was empty. I connected to city water. I use an adjustable regulator so I know the water pressure was 45 psi. The next morning the fresh water tank was heavily dripping water out of the overflow. I turned on the bathroom and kitchen faucets and drained the 45 gallon fresh water tank.

I can only presume the fresh water pump somehow allowed water to back fill the fresh water tank from the city water inlet. Imagine if it hadn't overflown I would have never know. Not only would I have been hauling 360 lbs of water I would imagine that much weight in the tank could cause the tank to break loose while driving.

The only thing I can think to do is replace the diaphragm in the pump. It only happened the one time but I'm not sure I can trust it to not happen again.

Anyone ever seen this problem?

Dustin