we've had this happen several times, even after replacement of the Anderson 4Way Valve by the factory on two occassions - so...
i decided to get wise and install an in-line faucet style 'cut off' valve between the Anderson valve and the water line to the water Tank. now I can rest assured that the filling does not happen unless I want it to.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada - Northwest, GA! (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )