SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
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Figure 4
Furnace Setup Switch Description
A11575
E
S
U
F
O
N
O
I
T
P
I
R
C
S
E
D
N
O
I
T
I
S
O
P
L
A
M
R
O
N
E
M
A
N
H
C
T
I
W
S
H
C
T
I
W
S
P
U
T
E
S
SW1-1
Status Code Recovery
OFF
Turn ON to retrieve up to 7 stored status codes for
troubleshooting assistance when R thermostat lead is
disconnected.
SW1-2
Minimum Heat Only
(Adaptive Heat Mode
when SW1-2 and SW4-2
are OFF)
OFF
When SW1-2 and SW4-2 are OFF allows Modulating operation
with a single stage thermostat. Turn ON SW1-2 when using
two-stage thermostat to allow Minimum Heat operation when
R to W/W1 closed and a Maximum heat operation when R to
W/W1 and R to W2 close.
T
ON t i
Mi i
H
t
d I t
di t H
t
Furnace Setup Switch Description
SW1-3
Min/Int Heat Rise
Adjustment
OFF
Turn ON to increase Minimum Heat and Intermediate Heat
airflow by 18 percent. This compensates for increased return
air temperature caused with bypass humidifier. This also
increases the Intermediate Heat inducer speed 15 percent.
SW1-4
Comfort/Efficiency
Adjustment
ON
Turn ON to decrease Minimum heat airflow by 10 percent,
Intermediate Heat airflow 7.5 percent and Maximum Heat
airflow 17.5 percent for maximum comfort.
SW1-5
CFM per ton adjust
OFF
Turn ON for 400 CFM per ton, Turn OFF for 350 CFM per ton.
See also SW4.
SW1-6
Component Self Test
OFF
Turn ON to initiate Component Self Test for troubleshooting
assistance when R thermostat lead is disconnected. Turn
OFF when Self Test is completed.
Bl
Off D l
i
dj
bl
d
SW1-7 & SW1-8
Blower OFF delay
ON or OFF
Blower Off Delay time – adjustable 90 seconds to 180
seconds. See table in Adjustments section or refer to unit
wiring diagram.
SW4-2
Intermediate Heat
Only
(Adaptive Heat Mode
when both SW1-2 and
SW4-2 are OFF)
OFF
Allows additional CFM per ton selections when used with SW
SW4-3
CFM per ton Adjust
OFF
Allows additional CFM per ton selections when used with SW
1-5
325 CFM per ton (nominal) when SW 4-3 ON and SW 1-5 OFF
350 CFM per ton (nominal) when SW 4-3 OFF and SW 1-5 OFF
370 CFM per ton (nominal) when SW4-3 ON and SW 1-5 ON
400 CFM per ton (nominal) when SW 1-5 ON and SW 4-3 OFF
See Air Delivery Tables for model specific CFM vs. static
pressure
p
AIR CONDITIONING (A/C) SETUP SWITCHES
SW 2, AC (Cooling Airflow) SETUP SWITCHES
The AC setup switch selects desired cooling or high stage cooling (two stage units) airflow.
O
N
1
2
3
1
SW2
See Cooling Air Delivery Tables for specific switch settings
CONTINUOUS FAN (CF) SETUP SWITCHES
SW 3, CF (Continuous Fan) SETUP SWITCHES
The CF setup switch selects desired Continuous Fan Airflow
The CF switch position is the Low Cooling airflow selection for two stage cooling units.
O
N
1
2
3
1
SW3
AC
SW 3 cannot be set for airflow higher than SW 2
See Continuous Fan Air Delivery Tables for specific switch settings
CF
When SW1-2 and SW4-2 are OFF allows Modulating operation
with a single stage thermostat. Turn ON SW4-2 when using
two-stage thermostat to allow Intermediate Heat operation
when R to W/W1 closed and a Maximum heat operation when
R to W/W1 and R to W2 close.
