Fan Mode:
1.On a call for fan operation, the thermostat applies 24 VAC to the G terminal on the furnace control board.
2.The circulating air blower is energized im- mediately on the heating speed.
3.If the furnace is operated in the continuous ON position at the thermostat and is then switched to AUTO, the circulating blower will operate for a specified delay (factory set at 120 seconds).
Furnace Fails to Operate
If the furnace does not operate check the follow- ing:
1.Is the thermostat operating properly?
2.Are the blower compartment door(s) in place?
3.Is the furnace disconnect closed?
4.Has the circuit breaker tripped or the control board fuse burned open?
5.Is the gas turned on?
6.Are any manual reset switches open?
7.Is the filter dirty or plugged?
8.Is the flame sensor coated? (Remove and clean with emery cloth.)
If the furnace locks out after 5 attempts for ignition, it will try again every hour if a call for heat remains. If the inducer and circulating air blowers are operating, and items 1 through 8 have been checked, press the red reset button on the vent safety switch. (See Figure 28.) If the furnace operates after depressing the reset button, contact a qualified serviceman to identify and repair the problem.
If the furnace continues to not operate, depress the red reset buttons on the flame rollout switches. (See Figure 28.) If the furnace operates after depressing the reset buttons, contact a qualified servicemen to identify and repair the problem.
Twinning of Two Furnaces
The control board on these furnaces is capable of being twinned to another G6 furnace, pro- vided the circuit boards are both UTEC type. If using UTEC control boards, leave the fuses installed on each board. The thermostat wires and the 1/4 inch
Thermostat
W G Y R
R
C
Y
G
W
Twin Terminal
R
C
Y
G 
W
Twin Terminal
A/C
Unit
Figure 29. Twinning
34