Originally Posted by Mr J
Fresh water tank draining while driving or sitting on a slope. Has anyone added a P Trap or shut off valve to the overflow tube? Or are there other solutions to correct the problem? Any suggestions and photos of fix would help. Also is the overflow tube also used as a. Ent tube for the tank or can it be shut off after filling the tank. As always thanks for your quick responses and help.
We fitted an electric water valve in the overflow line taking the feed for it off the pump supply. This means that when the pump is switched on, water or air can flow as necessary. When the pump is switched off the valve closes and seals the tank. So you just have to remember to switch the pump on when you are filling the tank and off when you are travelling.
CAVEAT If you overfill the tank, you will get the top of the tank bulging upwards until it can be caught up on the slideout ram mechanism. The result is a large and horrible hole in the top of the tank and the tank wrenched past its restraining wood blocks in synchronisation with the movement of the slideout and multiple shouts of "Water everywhere!!""