Why does my washing machine overfill?

Replace the washer water-level pressure switch

The water-level pressure switch detects the water level in the wash tub. If the water-level pressure switch is defective, the washer won't fill properly. It could not fill at all or it could overfill even to the point of overflowing. If the pressure switch doesn't accurately detect and control the water level in the washer, replace it.

Replace the washer water inlet valve assembly

The water inlet valve assembly is a set of water valves that control the flow of water into the washer. Replace the water valve assembly if the washer won't fill and start because a valve doesn't open, or if the washer overfills because the valve doesn't close.

Replace the washer main control board

The main electronic control board, also called the mother board, governs the timing and execution of the washer component functions. It controls the fill valves, the drive motor and the drain pump.