White-Rodgers 1311-104 1-1/4" Sweat, 3-Way, Normally Open/Closed Zone Valve

White-Rodgers 1311-104 Zone Valve Normally Open or Normally Closed 3 Wire. with Auxiliary Switch.
These water valves provide a low cost system of zoned temperature control wherever hot water is the heating medium.
Power Failure. Valve Stays in Place, when power is restored the valve will automatically return to command of room thermostat.
Manual Operation if Valve is in Closed position during Power Failure the valve may be opened by turning dial clockwise with your thumb until word “Open" appears.
FEATURES
• Quiet operation.
• Valve stem made of stainless steel.
• Automatic recycling manual operator shows valve position at all times.
• Built-in auxiliary contacts to control burner or circulator relay.
• Motor can be removed from valve assembly without draining system.
As the thermostat calls for heat, the valve motor is energized and begins to open the valve. Soon thereafter side “A" of motor switch makes with the holding contacts. This contact provides a holding circuit to prevent the valve from stopping part way through its cycle if the thermostat is changed to the satisfied position. Just before the valve reaches the full-open position, side “B" of motor switch closes (providing a low voltage auxiliary circuit for starting burner and/or circulator). The motor stops with the valve in the open position when side “A" of motor switch breaks the holding contact. (Completing a circuit through contact “6" and the thermostat anticipator.) When thermostat is satisfied, the valve motor is again energized.
Just after the valve starts to close, side “A" of motor switch makes with holding contact providing a holding circuit. The side “B" of motor switch opens (breaking auxiliary circuit), and side “A" of motor switch makes with contact “4" then breaks the holding circuit stopping the valve in the closed position.