Geeze trevman, listen to what the others are saying before you give bad information.
Two leads are the motor that opens the valve, remove the power and a spring closes it. The other two leads are from a switch that closes when the valve is fully open.
As was said, usually all the switches are connected in parallel and then to what normally would be the thermostat terminals (T&T or R,W) on the boiler. When any zone valve opens it's switch closes and starts the boiler and circulator.
The motor leads from each valve need to go to it's respective air handler. The controls there need to provide the 24 volts to it when the thermostat calls for heat. This can be done in a number of ways and might even require an additional relay and transformer on your part. Depends on what's there. let us know.
-Hal
[This message has been edited by hbiss (edited 12-03-2005).]
