Step 1
Turn off electrical power to the heating system, at the breaker box.
Step 2
Remove the valve cover.
Step 3
Unscrew the single screw that secures the motor unit to the valve body.
Step 4
Push the valve's manual actuating lever -- located on the end of the valve below the power wire connector -- into the "Open" position, and hold it there.
Step 5
Lift the motor unit up and away from the valve body. Release the manual actuating lever, and allow the valve to spring back into the "Closed" position.
Step 6
Cut the two wires leading from the motor to the plastic terminal connector. Leave enough existing wire at the connector to splice the new motor wires. Strip one-half inch of insulation from the ends of both wires.
Step 7
Push the valve's manual actuating lever -- located on the end of the valve below the power wire connector -- into the "Open" position, and hold it there. Install the new motor unit into the valve body. Insert the single mounting screw and tighten. Release the manual actuating lever, and allow the valve to spring back into the "Closed" position.
Step 8
Splice the two wires from the motor to the two existing wires, using the supplied screw-on connectors.
Step 9
Replace the valve cover. Restore power to the system, at the breaker box. Test the action of the valve by adjusting the thermostat to call for heat.