Whirlpool Dishwasher Not Filling With Water: Inlet Valve, Float, and Supply Fixes

Whirlpool dishwasher not filling has a specific diagnostic sequence. First: check the water supply valve under the sink - it must be fully open. Second: check the inlet screen on the water inlet valve at the back of the dishwasher. Mineral deposits clog this fine mesh screen and restrict flow. Third: check the float assembly inside the dishwasher (small dome in the front corner of the tub). If the float is stuck in the UP position (from food debris underneath it), the dishwasher thinks the tub is full and won't fill. Lift the float and clean underneath it. Fourth: if all physical checks pass, the water inlet valve solenoid has failed ($15-30, it won't open even when the board sends the signal). Whirlpool displays H2O error when it detects no water during the fill phase.