Learn how to wire a Taco 4 zone switching relay with our easy-to-follow diagram. Control the heating zones in your home efficiently and effectively.. Wiring Procedure: End Switches (Low Voltage Dry Contacts): Main The main end switch closes when any zone thermostat calls for heat and connects to T-T on boiler operating control.
Note: When using Alternative Wiring diagram, the boiler oper-ating control's ZC terminal will see the load of the circulator(s). Warning: When using Alternative Wiring diagram, wiring instructions must be followed so power originates from the boiler aquastat. Failure to follow these wiring instructions may result in a secondary source of power being connected to the boiler that may activate.. Note: When using Alternative Wiring diagram, the boiler oper-ating control's ZC terminal will see the load of the circulator(s). Warning: When using Alternative Wiring diagram, wiring instructions must be followed so power originates from the boiler aquastat.