TWINNING WIRING DIAGRAM – Single Stage Thermostat
TWINNING WIRING DIAGRAM – Two Stage Thermostat
SW1 Switch 3:
TWIN
SW1 Switch 4:
2nd
SW1 Switch 3:
TWIN
SW1 Switch 4:
2nd
SW1 Switch 3:
TWIN
SW1 Switch 4:
1st
SW1 Switch 3:
TWIN
SW1 Switch 4:
1st
FAULT CODES
LEDS
Flashes
Fault condition
GREEN
ON Steady
Normal operation
1 Flash
Ignition failure (5 trials)
2 Flashes
Pressure switch stuck open
3 Flashes
Limit switches open
4 Flashes
Pressure switch stuck closed
5 Flashes
Twinning problem
6 Flashes
Brownout voltage
7 Flashes
Hot & Neutral reversed or no ground connected
Continuous
Gas valve relay shorted
1 Flash every 2 sec.
Flame fault
YELLOW
Continuous
Low flame or no flame
ON
Flame present
The control has built-in self-diagnostic capability. If a system problem occurs, a blinking LED
shows a fault code.
