I just filled the fresh water tank for our first time on new-to-us 2010 Keystone Alpine. I stood inside, kept testing the water level, it never moved - and then it started to overflow at the outside. ...
do you have a gravity fill port someplace? my winnie didn't, it had a switch to either use city water or to fill the tank. my bounder had a small valve in one of the lines to let water into the tank. bumpy