Operation/external diagnostics - when any thermostat calls for heat, the appropriate zone valve is energized and the yellow light goes on
When the zone valve is fully open, the red light goes on and energizes the end switch relay
The green light should always be on, indicating that power is connected
Priority operation - when zone 4 is switched to the priority setting and is actuated, all other zones will stop operation until zone 4 is satisfied
When zone 4 is not switched to priority, all zones will operate independently
When a circulator is used on the priority zone instead of a zone valve, jumper 3 and 4 of the priority zone
Priority protection operation - when the priority zone calls continuously for more than one hour, power is returned to all the other zones, allowing each zone to function independently
Once the priority zone is satisfied, the control's auto-reset is activated and the priority zone is again allowed to have priority for up to one hour starting from when it calls next
