GC9C96 Service Manual
SYSTEM OPERATION
15
• The 2nd stage gas heat speed of the indoor blower is
energized
• When the thermostat is satised:
• The gas valve is de-energized.
• The inducer remains energized for the post purge period
(15 seconds).
• The indoor blower runs for the selected o delay period
(90 seconds by default, adjustable from 30 – 180
seconds).
• The control board receives a 24 VAC signal on the W2
terminal.
• The inducer motor is enabled at high speed.
• Closure of the 2nd stage pressure switch will energize
the high re stage of the gas valve.
• The 2nd stage gas heat speed of the indoor blower is
energized.
To change the main blower speed in HEATING mode, follow
the following steps:
1. Press the left or right switch until LED displays “gA1” (for
single-stage HEATING) or “gA2” (for two-stage HEATING).
Press the center switch and LED will display the selected
speed number as Fxx (xx: Blower speed number).
2. The control will rotate available speed number every time
left / right switches are pressed. The table below shows
the available speeds for low & high heat mode.
3. Press the center switch to save the selection.
Always refer to the Heating Chart to choose from
available heating speeds
THERMOSTATCALL AVAILABLESPEEDS
W/W1
F01(DEFAULT)
F03
F04
W2
F02(DEFAULT)
F04
F05
To change the main blower speed in circulation mode, follow
the following steps:
1. Press the left or right switch until LED displays “FSd”.
Press the center switch and LED will display the selected
speed number as Fxx (xx: Blower speed number from 1
to 9). F03 is the default speed for circulation.
2. The control will rotate available speed number every time
left/right switches are pressed. All 9 speeds are available
for circulation.
3. When the center switch is pressed, the current displayed
speed will be selected, and control will immediately apply
that speed setting.
THERMOSTAT
CALL
AVAILABLE
SPEEDS
G
F01
F02
F03(DEFAULT)
F04
F05
F06
F07
F08
F09
On a call for low stage cooling, the Y/Y1 or Y/Y1 and G
thermostat contacts close signaling the furnace control board
with 24 VAC on Y/Y1 or Y/Y1 and G terminals.
• The 7-Segment will display the cool mode:1AC
• The compressor and condenser fan are energized.
• The circulator fan is energized at low cool speed after
a cool on delay. The electronic air cleaner will also be
energized.
• After the thermostat is satised, the compressor is de-
energized and the Cool Mode Fan O Delay period begins.
• Following the Cool Mode Fan O Delay period, the cool
circulator and air cleaner relay are de-energized.
On a call for 2nd stage cooling, the Y2 or Y2 and G thermostat
contacts close signaling the furnace control board with 24
VAC on Y2 or Y2 and G terminals.
• The 7-Segment will display the cool mode: 2AC
• The compressor and condenser fan are energized.
• The circulator fan is energized at cool speed after a
cool on delay. The electronic air cleaner will also be
energized.
• After the thermostat is satised, the compressor is
de-energized and the Cool Mode Fan O Delay period
begins.
• Following the Cool Mode Fan O Delay period, the cool
circulator and air cleaner relay are de-energized