Wax motor

For the plunger to withdraw, a biasing force is usually required to overcome the mechanical resistance of seals that contain the liquid wax.

If power is lost the door remains briefly locked, designed to be longer than the high speed spin cycle coast-down time, then reliably unlocks as the wax cools.

Wax motors are also commonly used to drive zone valves in hydronic (hot water) heating systems.

The wax motor acts like a solenoid when activated by the dishwasher's timer or control, and the piston operates the mechanism which then releases the catch for the dispenser door.

A paraffin microactuator is a type of wax motor, often fabricated by microelectromechanical systems (MEMS) technology or sometimes precision mechanics.