You could have a bad water valve, timer, pressure switch or pressure hose, with no power applied to unit you have a bad water valve/fill valve. Look for holes of any size in pressure hose (should be air tight if not the difference in pressure will allow unit to keep filling up). The timer tells the fill valve when to turn on by the use of cams and contact armatures--when unit is filling check for voltage at the fill valve if voltage is present when unit should of stopped filling like on a small water level you have a bad timer. On your pressure switch use your schematics and with unit unplugged check for continuity between the common and full and empty contacts (do not remove pressure hose with water in unit)-- if pressure switch remains in the empty position when full of water the pressure switch is bad. Once you have found the problem and resolved it make sure to run unit on a spin cycle with no water to allow pressure switch to reset it self otherwise it may overflow again. good luck
Kevin, February 2006
