The Z60000 consists of an operator and a valve assembly. The operator includes a lever operated by a wax-filled heat motor and an opposing drive spring. All models include a normally closed blade switch which controls power to the motor heater when the valve is energized. Z60000 also has normally open blade type end switch, which controls a circulator pump relay. The valve assembly consists of a brass valve body, bonnet and a spring-loaded valve insert.
When the valve is energized by a call for heat from the thermostat, an electric heater melts the wax inside the heat motor. The melting wax expands, driving the heat motor piston up and forcing the spring-loaded lever away from the valve stem. When the lever starts to rise, it closes the normally open end switch to energize the circulator pump relay. The spring in the valve assembly pushes the valve stem up to follow the lever, and slowly lifts the valve disc off the valve seat.