….As you probably know by now, the Avalanche was a very low production run by WRV, so std. Alpine owners don't have much, if any, first-hand experience to help you. Your situation sounds like the dump valve on the water tank is open....early model Alpines have a 1 1/2" dump slide valve with a cable remotely attached to a T-handle--located on the side wall, in the basement, just behind the propane tank, on the driver's side.
2003 40' MDTS
New Braunfels, Texas