1989 Chieftain city water question

[ldpm]

Hi folks, I'm very new to this classic motorhome, and I think I'm doing something wrong when attempting to use city water at a campsite.

These old models have a combined tank fill and city water inlet, and a valve that switches between them. I've closed the winterizing valves under the bed and successfully filled the fresh water tank, but when I then close the valve, which should put me on city water and bypass the demand pump and storage tank, water comes out the tank's overflow port onto the ground anyway. Is this a broken valve or am I missing a crucial step? I've read the manual and I THINK I'm doing what it says.

Thanks!

[Morich]

I think you have it right but let me check. A knob labeled something like fill and normal, perhaps? That part is kind of plain as we go fill for filling the tank and then we do need to remember to switch it back to normal or we often don't get much pressure if left in the fill position. If that sounds what you see, we may be looking at a defective valve.
Theses are called a diverter valve as they divert or "shift" the water flow, not cut it off.
A couple things to check might be that the handle is not lose and just not fully moving the ball valve inside or something silly like that but there is also a pretty good chance that the ball has become worn and letting water slip past when in the normal position and that water winds up overflowing the tank. Or could there be something keeping it from closing? Usually not terribly hard to replace but worth looking at the ball once we get it out as "weird" happenings are almost standard on RV! Likely can find one local rather than order from Winnebago, etc.