Washer: Why your washing machine won't finish its cycle

The lid switch on a top-load washer is a safety switch that detects whether the washer lid is closed. The lid must be closed when the basket spins; if the washer incorrectly senses that the lid is open, it won’t spin and drain after the wash cycle.

Some top-load models require that the washer lid be closed before the washer drive motor runs. An open lid prevents some top-load washers from filling.

If the lid switch isn't detecting whether the lid is closed, replace the switch.

The shifter assembly-also called the actuator-in a top-load washer is mounted on the bottom of the gearcase. The shifter assembly's motor shifts the drive system between the agitation mode and the spin mode. A sensor on the shifter monitors the position of the drive system during the wash cycle. If the motor, sensor or mechanical parts of the shifter assembly fail, the washer stops and signal an error code. Replace the shifter assembly if it malfunctions.

The door lock assembly on a front-load washer includes a safety switch that detects whether the washer door is closed, a latch and a locking mechanism. If any of these components fails when the door is open, the door won't lock; if a component fails with the door is closed, the door won't open. Replace the entire assembly if any component fails.

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.

The timer — also called a cycle selector — is the dial you use to set the cycle on a washing machine with mechanical controls. The timer makes the washer move through its cycles, from initial filling to final spin. Replace the timer if it doesn’t advance the washer through its cycles.

The drain pump removes water from the washer at the appropriate times during the wash cycle. The pump's bearing can seize, the seal can fail or the impeller blades can break. The belt on a belt-driven pumps can break, and the pulley can shear off. A humming noise when the washer is full of water is a common symptom of a failing pump. In some cases, you can repair the pump by clearing it of debris, fixing wiring failures or replacing a seal. If the pump can't be repaired or rebuilt, replace it.

The motor control board is a circuit-control board in a front-load washer that's usually in the bottom of the washer next to the drive motor. It monitors and controls the drive motor speed and direction for the tumble and spin actions during the cycle. If the motor doesn't run, the motor control board might need to be replaced.

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.