27
W G Y R
Thermostat
A/C
Unit
Twin
Terminal
R
C
Y
G
W
R
C
Y
G
W
Twin
Terminal
Figure 15. Twinning
4.
The circulating air blower is de-energized
after a 90-second delay.
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
immediately 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
following:
1.
Is the thermostat operating properly?
2.
Is the blower compartment door 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 steel wool.)
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 burner roll-out switches (See Figure 14).
If the furnace operates after depressing either
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 roll-out
switches. (See Figure 14.) If the furnace oper-
ates after depressing the reset buttons, contact
a qualified servicemen to identify and repair the
problem.
Twinning
The control board on these furnaces is capable
of being twinned to another furnace of the same
series or a G series furnace with a UTEC control
board. If using UTEC control boards, leave the
fuses installed on each board. The thermostat
wires and the 3/16 inch quick-connect terminals
marked “TWIN” on the furnace controls must
be wired for twinning. (See Figure 15.)
