KeepRite F9MAC Series Installation instructions

Printed in U.S.A. 440 04 4201 03 July 2012
SERVICE AND TECHNICAL
SUPPORT MANUAL
Modulating, Variable Speed Blower Motor
35” Tall, High Efficiency Condensing Gas Furnace
(
F/G
)
9MAC
Save this manual for future reference.
Safety Labeling and Signal Words
DANGER, WARNING, CAUTION, and NOTE
The signal words DANGER, WARNING,
CAUTION,and NOTE are used to identify levels of
hazard seriousness. The signal word DANGER is
only used on product labels to signify an immediate
hazard. The signal words WARNING, CAUTION,
and NOTE will be used on product labels and
throughout this manual and other manual that may
apply to the product.
DANGER −Immediate hazards which will result in
severe personal injury or death.
WARNING −Hazards or unsafe practices which
could result in severe personal injury or death.
CAUTION −Hazards or unsafe practices which
may result in minor personal injury or product or
property damage.
NOTE −Used to highlight suggestions which will
result in enhanced installation, reliability, or
operation.
!WARNING
Signal Words in Manuals
The signal word CAUTION is used throughout
this manual in the following manner:
!CAUTION
Signal Words on Product Labeling
Signal words are used in combination with
colors and/or pictures or product labels.
The signal word WARNING is used throughout
this manual in the following manner:
Safety−alert symbol
When you see this symbol on the unit and in
instructions or manuals, be alert to the
potential for personal injury.
TABLE OF CONTENTS
START−UP, ADJUSTMENT, AND SAFETY CHECK 4...........
SELECT SETUP SWITCH POSITIONS 4.....................
PRIME CONDENSATE TRAP WITH WATER 4.................
PURGE GAS LINES 5......................................
ADJUSTMENTS 5.........................................
ADJUST TEMPERATURE RISE 8............................
ADJUST BLOWER OFF DELAY (HEAT MODE) 9..............
ADJUST COOLING AIRFLOW 9.............................
ADJUST CONTINUOUS FAN AIRFLOW 9....................
ADJUST THERMOSTAT HEAT ANTICIPATOR 11...............
CHECK SAFETY CONTROLS 12.............................
CHECKLIST 12.............................................
COOLING AND HEATING AIR DELIVERY 17...................
SERVICE AND MAINTENANCE PROCEDURES 21.............
ELECTRICAL CONTROLS AND WIRING 21...................
CLEANING AND/OR REPLACING AIR FILTER 23..............
CLEANING BURNERS AND FLAME SENSOR 25...............
SERVICING HOT SURFACE IGNITER 26......................
FLUSHING COLLECTOR BOX AND DRAINAGE SYSTEM 27....
CLEANING CONDENSATE DRAIN AND TRAP 27..............
WINTERIZATION 28........................................
SERVICE LABEL 29.........................................
TROUBLESHOOTING CHART −FLOW CHART 31.............
TROUBLESHOOTING GUIDE −FLOW CHART 32..............
SEQUENCE OF OPERATION 34.............................
PARTS REPLACEMENT INFORMATION GUIDE 38.............
PRODUCT NOMENCLATURE 39.............................
MODELS
(F/G)9MAC0601714A
(F/G)9MAC0602120A
(F/G)9MAC0801714A
(F/G)9MAC0802120A
(F/G)9MAC1002122A
(F/G)9MAC1202422A
Use of the AHRI Certified TM Mark indicates a
manufacturer’s participation in the program.
For verification of certification for individual
products, go to www.ahridirectory.org .

Specifications are subject to change without notice.
2440 04 4201 03
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock,
or other conditions which may cause death, personal injury, or
property damage. Consult a qualified installer, service agency,
or your distributor or branch for information or assistance. The
qualified installer or agency must use factory−authorized kits or
accessories when modifying this product. Refer to the individual
instructions packaged with the kits or accessories when
installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions
thoroughly and follow all warnings or cautions included in
literature and attached to the unit. Consult local building codes,
the current editions of the National Fuel Gas Code (NFCG)
NFPA 54/ANSI Z223.1, and the National Electrical Code (NEC)
NFPA 70.
In Canada refer to the current editions of the National standards
of Canada CAN/CSA−B149.1 and .2 Natural Gas and Propane
Installation Codes, and Canadian Electrical Code CSA C22.1.
Recognize safety information. This is the safety−alert symbol
. When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand these signal words; DANGER, WARNING, and
CAUTION. These words are used with the safety−alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies hazards
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which may result in minor personal
injury or product and property damage. NOTE is used to
highlight suggestions which will result in enhanced installation,
reliability, or operation.
!WARNING
PERSONAL INJURY, AND/OR PROPERTY DAMAGE
HAZARD
Failure to carefully read and follow this warning could
result in equipment malfunction, property damage,
personal injury and/or death.
Installation or repairs made by unqualified persons could
result in equipment malfunction, property damage,
personal injury and/or death.
The information contained in this manual is intended for
use by a qualified service technician familiar with safety
procedures and equipped with proper tools and test
instruments.
Installation must conform with local building codes and
with the Natural Fuel Gas Code (NFCG) NFPA 54/ANSI
Z223.1, and National standards of Canada
CAN/CSA−B149.1 and .2 Natural Gas and Propane
Installation Codes.
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal
injury or death.
Before performing service or maintenance operations
on unit, always turn off main power switch to unit and
install lockout tag. Unit may have more than one power
switch.
!WARNING
CARBON MONOXIDE POISONING AND FIRE
HAZARD
Failure to follow safety warnings could result in personal
injury, death, and/or property damage.
This furnace is not designed for use in mobile homes,
trailers or recreational vehicles.
!CAUTION
CUT HAZARD
Failure to follow this caution may result in damage
personal injury.
Sheet metal parts may have sharp edges or burrs. Use
care and wear appropriate protective clothing, safety
glasses and gloves when handling parts and servicing
furnaces.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
440 04 4201 03 3
Specifications subject to change without notice.
START−UP CHECK SHEET
For Variable Speed Models (F/G)9MAC
(This sheet is optional. Keep for future reference.)
Date of Start−Up:
Dealer Name:
Address:
City, State(Province), Zip or Postal Code:
Phone:
Owner Name:
Address:
City, State(Province), Zip or Postal Code:
Model Number:
Serial Number:
Setup Checks
Check the box when task is complete.
All Electrical Connections Tight?
Have hoses been relocated for furnace U/D/H
application?
Condensate Drain Connected?
Condensate Drain Trapped?
Manual Gas Shut−off Upstream of Furnace/Drip Leg
Gas Valve turned ON?
Type of Gas: Natural: Propane:
Filter Type and Size:
Shade in Final Furnace Settings Below:
Calculated Input (BTU) Rate: (See Checks and
Adjustments Section).
Heating Check
Measured Line Pressure During High Heat:
Measured Manifold Pressure: Max Heat
Min Heat
Temperature of Supply Air: Max Heat
Min Heat
Temperature of Return Air:
Temperature Rise (Supply −Return): Max Heat
Min Heat
In Rise Range (see furnace rating plate)?
Static Pressure (Ducts) High Heat: Supply
Return
Optional Check: CO?
CO2?
Cooling Check
Temperature of Supply Air:
Temperature of Return Air:
Temperature Difference:
Static Pressure (Ducts) Cooling: Supply
Return
Dealer Comments:

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
4440 04 4201 03
START−UP, ADJUSTMENT, AND SAFETY
CHECK
General
1. Furnace must have a 115-v power supply properly
connected and grounded.
NOTE: Proper polarity must be maintained for 115-v wiring.
Control status indicator light flashes code 10 and furnace does
not operate if polarity is incorrect or if the furnace is not
grounded.
2. Thermostat wire connections at terminals R, W/W1, G,
Y/Y2, etc. must be made at 24-v terminal block on
furnace control. See communicating wall control
instructions for proper wiring of communicating controls.
3. Natural gas service pressure must not exceed 0.5 psig
(14- in. w.c., 350 Pa), but must be no less than 0.16 psig
(4.5-in. w.c., 1125 Pa).
4. Blower door must be in place to complete 115-v
electrical circuit and supply power to furnace.
UNIT OPERATION HAZARD
Failure to follow this caution may result in intermittent unit
operation or performance dissatisfaction.
These furnaces are equipped with a manual reset limit
switch in burner assembly. This switch opens and shuts off
power to the gas valve if an overheat condition (flame
rollout) occurs in the burner assembly/enclosure. Correct
inadequate combustion-air supply, improper gas pressure
setting, improper burner or gas orifice positioning, or
improper venting condition before resetting switch. DO
NOT jumper this switch.
CAUTION
!
Before operating furnace, check flame rollout manual reset
switch for continuity. If necessary, press button to reset switch.
EAC-1 terminal is energized whenever blower operates. HUM
terminal is only energized when blower is energized in heating.
Select Setup Switch Positions
There are four sets of setup switches on the furnace control
board. These switches configure the furnace for correct
application requirement. They also select the airflow settings for
Air Conditioning and Continuous Fan airflows.
The Setup Switch locations are shown and described on
Figure 3, Figure 4,Table 3 and Table 6. The set up switches
are also shown on the unit wiring label.
Setup Switches (SW1)
The furnace control has eight setup switches that may be set to
meet the application requirements. Refer to Figure 4 and
Adjustments section for set up switch configurations.
To set these setup switches for the appropriate requirement:
1. Remove blower door.
2. Locate setup switches on furnace control.
3. Configure the set-up switches as necessary for the
application.
4. Replace blower door.
NOTE: If a bypass humidifier is used, setup switch SW1-3
(Min/Int Rise Adjust) should be in ON position. This
compensates for the increased temperature in return air
resulting from bypass.
NOTE: If modulating dampers are used, blower motor
automatically compensates for modulating dampers.
Air Conditioning (A/C) Setup Switches (SW2)
The air conditioning setup switches are used to match furnace
airflow to required cooling airflow or high stage cooling airflow
when a two−stage outdoor unit is used. Refer to Figure 4 and
the Adjustments section for set up switch configurations.
To set the desired cooling airflow:
1. Remove blower door.
2. Locate A/C setup switches on furnace control.
3. Determine air conditioning tonnage used.
4. Configure the switches for the required cooling airflow.
NOTE: Incorrect airflow caused by improper A/C switch setup
may cause condensate blow−off or a frozen indoor coil in the
cooling mode.
5. Replace blower door.
Continuous Fan (CF) Setup Switches (SW3)
The CF setup switches are used to select desired airflow when
thermostat is in continuous fan mode or to select low-cooling
airflow for two-speed cooling units. Refer to Figure 4 and the
Adjustments section for set up switch configurations.
1. Remove blower door.
2. Locate CF setup switches on furnace control.
3. Determine desired continuous fan airflow or low-cooling
airflow.
4. Configure the switches for the required continuous fan or
low−cooling airflow.
5. Replace blower door.
Additional Setup Switches (SW4)
The furnace control has three additional setup switches labeled
SW4.
Setup switch SW4-2 can be used to lock the furnace into
intermediate heat. When setup switch SW4-2 is ON it will over
ride setup switch SW1-2 if it is ON. SW4−3 is used to adjust
airflow. Refer to Figure 4 and the Adjustments section for set
up switch configurations.
1. Remove blower door.
2. Locate setup switch SW4 on furnace control.
3. Configure the switches for the required heat stages air
flow if necessary.
4. Replace blower door.
Prime Condensate Trap with Water
!WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow these warnings could result in personal injury
or death.
Failure to use a properly configured trap or NOT
water-priming trap before operating furnace may allow
positive pressure vent gases to enter the structure through
drain tube. Vent gases contain carbon monoxide which is
tasteless and odorless.
UNIT OPERATION HAZARD
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
Condensate trap must be PRIMED or proper draining may
not occur. The condensate trap has two internal
chambers which can ONLY be primed by pouring water
into the inducer drain side of condensate trap.
CAUTION
!
1. Remove upper and middle collector box drain plugs
opposite of the condensate trap. (See Figure 1)
2. Connect field-supplied 5/8-in. (16 mm) ID tube with
attached funnel (see Figure 1) to upper collector box
drain connection.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 5
3. Pour one quart (liter) of water into funnel/tube. Water
should run through collector box, overfill condensate
trap, and flow into open field drain.
4. Remove funnel; replace collector box drain plug.
5. Connect field-supplied 5/8-in. (16 mm) ID tube to middle
collector box drain port.
6. Pour one quart (liter) of water into funnel/tube. Water
should run through collector box, overfill condensate
trap, and flow into open field drain.
7. Remove funnel and tube from collector box and replace
collector box drain plug.
Figure 1 Priming Condensate Drain
L11F065
Representative drawing only, some models may vary in appearance.
Purge Gas Lines
If not previously done, purge the lines after all connections
have been made and check for leaks.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection
of leaks to check all connections. A fire or explosion may
result causing property damage, personal injury or loss of
life.
!WARNING
Adjustments
FURNACE DAMAGE HAZARD
Failure to follow this caution could result in reduced
furnace life.
DO NOT push or force gas valve adjusting screw. This
can result in damage to the adjustment screw resulting in
incorrect manifold pressure, which can result in a no heat
situation or shorten the life of the heat exchangers.
CAUTION
!
Figure 2 Orifice Hole
A93059
BURNER
ORIFICE
For proper operation and long term reliability, the Furnace input
rate must be within +/−2 percent of input rate on furnace rating
plate, or as adjusted for altitude.
The gas input rate on rating plate is for installations at altitudes
up to 2000 ft. (610 M).
NOTICE
The NATURAL GAS manifold pressure adjustments in Table 4
and Table 5 compensate for BOTH altitude AND gas heating
value. DO NOT apply an additional de−rate factor to the
pressures shown in Table 4 or Table 5. The values in these
Tables are NOT referenced to sea level; they are
AS−MEASURED AT ALTITUDE.
The heating content of natural gas at altitude may already
provide for a reduction in capacity or the furnace. Be sure to
obtain the expected in−season gas heating value of the gas
from the gas supplier BEFORE making any adjustments for
capacity or altitude. Refer to Table 4 or Table 5. No
adjustments to the furnace may be necessary at altitude for
certain gas heating values.
Refer to the instructions provided in the factory-specified
LP/Propane conversion kit for instructions for setting gas
manifold pressures for LP/Propane applications.
In the USA, the input rating for altitudes above 2000 ft. (610 M)
must be reduced by 2 percent for each 1000 ft. (305 M) above
sea level. Refer to Table 1. The natural gas manifold pressures
in Table 4 and Table 5 adjust for BOTH altitude and natural gas
heating value.
In Canada, the input rating must be reduced by 5 percent for
altitudes of 2000 ft. (610 M) to 4500 ft. (1372 M) above sea
level. The natural gas manifold pressures in Table 4 and
Table 5 adjust for BOTH altitude and natural gas heating value.
NOTE: For Canadian altitudes of 200 to 4500 ft. (610 to 1372
M), use USA altitudes of 2001 to 3000 ft. (611 to 914 M) in
Table 4 and Table 5.
To adjust manifold pressure to obtain the proper input rate, first,
determine if the furnace has the correct orifice installed. At
higher altitudes or different gas heat contents, it may be
necessary to change the factory orifice to a different orifice.
Tables have been provided in the furnace Service and
Technical Manual to match the required orifice to the manifold
pressure to the heat content and specific gravity of the gas.
NOTE: There are two sets of manifold pressure tables. Use
Table 4 for all models EXCEPT *9MAC0602120 Btuh model.
Use Table 5 for only the *9MAC0602120 model.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
6440 04 4201 03
To do this:
1. Obtain average heat value (at installed altitude) from
local gas supplier.
2. Obtain average specific gravity from local gas supplier.
3. Find installation altitude range for your installation in the
manifold pressure tables. See Table 4 for the 20,000
Btuh Max−Heat/8,000/Btuh Min−Heat per burner models
or Table 5 for model *9MAC0602120 only (20,200 Btuh
Max−Heat/8,000 Btuh Min−Heat per burner).
4. Find closest natural gas heat value and specific gravity in
Table 4 or Table 5 depending on furnace gas input rate.
5. Follow heat value and specific gravity lines to point of
intersection to find orifice size and maximum and
minimum manifold pressure settings for proper operation.
6. Check and verify burner orifice size in furnace. Never
assume orifice size. NEVER ASSUME ORIFICE SIZE.
ALWAYS CHECK AND VERIFY.
NOTICE
If orifice hole appears damaged or it is suspected to have been
redrilled, check orifice hole with a numbered drill bit of correct
size. Never redrill an orifice. A burr−free and squarely aligned
orifice hole is essential for proper flame characteristics.
7. Replace orifice with correct size, if required by Table 4
or Table 5 depending on furnace gas input rate. Use only
factory−supplied orifices. See EXAMPLE 1.
EXAMPLE 1:
(See Table 4)
0 - 2000 ft. (0 - 609.6M) altitude
Heating value = 1050 Btu/cu ft.
Specific gravity = 0.62
Therefore: Orifice No. 44
(Furnace is shipped with No. 44 orifices. In this example, all
main burner orifices are the correct size and do not need to be
changed to obtain proper input rate.)
Manifold pressure: 3.4-in. w.c. (847 Pa) for Maximum heat,
.55-in. w.c. (349 Pa) for Minimum heat
NOTE: To convert gas manifold Table pressures to Pascals,
multiply the in.w.c. value by 249.1 Pa/in. w.c. (1 in. wc. = 249.1
Pa).
Table 1 Altitude Derate Multiplier for U.S.A.
ALTITUDE
FT. (M)
PERCENT
OF DERATE
DERATE MULTIPLIER
FACTOR*
0–2000
(0−610) 0 1.00
2001–3000
(610−914) 4−6 0.95
3001–4000
(914−1219) 6−8 0.93
4001–5000
(1219−1524) 8−10 0.91
5001–6000
(1524−1829) 10−12 0.89
6001–7000
(1829−2134) 12−14 0.87
7001–8000
(2134−2438) 14−16 0.85
8001–9000
(2438−2743) 16−18 0.83
9001–10,000
(2743−3048) 18−20 0.81
* Derate multiplier factors are based on midpoint altitude for altitude range.
NOTE: For Canadian altitudes of 2000 to 4500 ft. (610 to
1372 M), use USA altitudes of 2001 to 3000 ft. (610 to 914
M).
Check Inlet Gas Pressure
The inlet gas pressure must be checked with the furnace
operating in maximum heat. This is necessary to make sure the
inlet gas pressure does not fall below the minimum pressure of
4.5−in. w.c. for natural gas. The maximum inlet gas pressure is
13.6−in. w.c. If the inlet pressure is too low, you will not be able
to adjust the manifold pressure to obtain the proper input rate.
To check the inlet gas pressure:
1. Make sure the gas supply is turned off to the furnace and
at the electric switch on the gas valve.
2. Remove the 1/8 inch NPT plug from the inlet pressure
tap on the gas valve.
3. Connect a manometer to the inlet pressure tap on gas
valve.
4. Turn on furnace power supply.
5. Turn gas supply manual shutoff valve to ON position.
6. Turn furnace gas valve switch to ON position.
7. Jumper the R to W/W1 and W2 thermostat connections
at the furnace control board.
8. When main burners ignite, confirm inlet gas pressure is
Between 4.5−in. w.c. and 13.6−in. w.c.
9. Remove jumper across thermostat connections to
terminate call for heat. Wait until the blower off delay is
completed.
10. Turn furnace gas valve electric switch to OFF position.
11. Turn gas supply manual shutoff valve to OFF position.
12. Turn off furnace power supply.
13. Remove manometer from the inlet pressure tap of the
gas valve.
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Re−install manifold pressure tap plug in gas valve to
prevent gas leak.
!WARNING
14. Apply pipe dope sparingly to end of inlet gas pipe plug
and re−install in the gas valve.
Adjust Manifold Pressure−Maximum Heat
The modulating furnace manifold pressure is set at two points.
The first point is Maximum Heat.
The second point is Minimum Heat. Do not adjust Intermediate
Heat manifold pressure. Intermediate Heat manifold pressure is
checked as part of the temperature rise, but is not adjustable.
Always adjust Maximum Heat first, then Minimum Heat.
NOTICE
DO NOT set maximum heat manifold pressure less than 3.2−in.
w.c. (947 Pa) for natural gas. If required manifold pressure is
outside this range, change main burner orifices to obtain
manifold pressure in this range.
To adjust manifold pressure to obtain input rate for Maximum
Heat:
1. Make sure the gas supply is turned off to the furnace and
at the electric switch on the gas valve.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 7
2. Remove the 1/8 inch NPT plug from the outlet pressure
tap on the gas valve.
3. Connect a manometer to the outlet pressure tap on gas
valve.
4. Turn on furnace power supply.
5. Turn gas supply manual shutoff valve to ON position.
6. Turn furnace gas valve switch to ON position.
7. Jumper the R to W/W1 and W2 thermostat connections
at the furnace control board.
8. After the main burners ignite and the blower starts,
confirm Maximum Heat manifold pressure is correct,
based on the manifold pressure tables in the installation
instructions.
9. To adjust the Maximum Heat manifold pressure, slowly
turn adjusting screw counterclockwise to decrease
manifold pressure or clockwise to increase manifold
pressure. Turn adjustment no more than one click per
second until you obtain the required manifold pressure.
10. Main burner flame should be clear blue, almost
transparent.
11. After adjusting the Maximum Heat manifold pressure,
remove jumpers across thermostat connections to
terminate the call for heat.
12. Wait for blower off-delay to finish then reset 115-v power
to furnace.
Adjust Manifold Pressure−Minimum Heat
To adjust manifold pressure to obtain input rate for Minimum
Heat:
1. Turn SW1−2 ON at the furnace control. Set up switch
SW4−2 must be OFF.
2. Jumper R and W/W1 thermostat connections on control
to start furnace.
3. After the main burners ignite and the blower starts,
confirm Minimum Heat manifold pressure is correct,
based on the manifold pressure tables in the installation
instructions.
4. To adjust the Minimum Heat manifold pressure, slowly
turn adjusting screw counterclockwise (out) to decrease
manifold pressure or clockwise (in) to increase manifold
pressure. Turn adjustment no more than one click per
second until you obtain the required manifold pressure.
5. After adjusting the manifold pressure, remove jumpers
across thermostat connections to terminate the call for
heat. Wait until the blower off delay is completed.
6. Move setup switch SW1-2 to the OFF position.
7. Turn gas supply manual shutoff valve to OFF position.
8. Turn off furnace power supply.
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Re−install manifold pressure tap plug in gas valve to
prevent gas leak.
!WARNING
9. Remove manometer from the inlet pressure tap of the
gas valve.
10. Apply pipe dope sparingly to end of inlet gas pipe plug
and re-install in the gas valve.
11. Re-install cap over adjustment screw on the top of the
gas valve.
Clocking the Meter
Verify natural gas input rate by clocking meter.
NOTE: Contact your HVAC distributor or gas supplier for metric
gas meter Tables, if required.
1. Turn off all other gas appliances and pilots served by the
meter.
2. Move setup switches SW1-2 to ON position and SW4-2
to OFF. This keeps furnace locked in Minimum Heat
operation when only W/W1 is energized or Maximum
Heat operation when R to W/W1 and W2 are jumpered.
3. Jumper R to W/W1 and W2. Run furnace for 3 minutes in
Maximum Heat operation.
4. Measure time (in sec) for gas meter to complete one
revolution and note reading. The 2 or 5 cubic feet dial
provides a more accurate measurement of gas flow.
5. Refer to Table 3 for cubic ft. of gas per hr. Multiply gas
rate cu ft./hr by heating value (Btuh/cu ft.) to obtain input
rate.
6. If clocked rate does not match required input from Step
5, increase manifold pressure to increase input or
decrease manifold pressure to decrease input. Repeat
steps 3 through 5 until correct maximum heat input is
achieved.
7. Remove jumpers across thermostat connections to
terminate the call for heat. Wait until the blower off delay
is completed then reset 115-v power to furnace.
8. Jumper R and W/W1 thermostat connections on control
to start furnace.
NOTE: Setup switches SW1-2 must be ON and SW4-2 must
be OFF. This keeps furnace locked in minimum heat operation
when R to W/W1 is energized. Repeat items 3 through 6 for
minimum heat operation until minimum heat input is achieved
9. Restore furnace to normal operating condition.
10. Remove jumpers across thermostat connections to
terminate the call for heat. Wait until the blower off delay
is completed.
11. Disconnect 115 VAC power to furnace.
12. Turn gas valve ON/OFF switch to OFF.
13. Remove water column manometer or similar device from
manifold pressure tap (if still connected).
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Re−install manifold pressure tap plug in gas valve to
prevent gas leak.
!WARNING
14. Replace manifold pressure tap plug to gas valve.
15. Turn gas valve ON/OFF switch to ON.
16. Move setup SW1-2 on furnace control to position
required for attached thermostat (OFF for single-stage
thermostats, ON for two-stage thermostats).
17. Check for gas leaks and verify furnace operation.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
8440 04 4201 03
Figure 3 Variable Speed Furnace Control for ECM Blower Motor (Modulating)
L11F091
24ïV THERMOSTAT
PL2 ćHOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
115ïVAC (L2) NEUTRAL
CONNECTIONS
115ïVAC (L1) LINE
VOLTAGE CONNECTIONS
EACï1 TERMINAL
(115ïVAC 1.0 AMP MAX.)
PL1 ćLOW VOLTAGE MAIN
HARNESS CONNECTOR
PL3 ćECM BLOWER
TERMINALS
HARNESS
TRANSFORMER 24ïVAC
CONNECTIONS
3ïAMP FUSE
STATUS AND COMM
LED LIGHTS
SW1 SETUP
SWITCHES AND
CONNECTOR
DELAY
MODEL PLUG
CONNECTOR
AIR CONDITIONING
(A/C) AIRFLOW
SETUP SWITCHES
COMMUNICATION
CONNECTOR
CONTINUOUS FAN
(CF) AIRFLOW
SETUP SWITCHES
OUTDOOR
BLOWER OFFï
IR TEMP
CONNECTOR
HUMIDIFIER
TERMINAL (24
A
VAC
0.5 AMP MAX.
FLASH
UPGRADE
CONNECTOR
(FACTORY
ONLY)
SW4 SETUP
SWITCHES
SOFTWARE
VERSION
PART NUMBER AND
DATE CODE WWYY
PL8 ïMODULATING
ï
CONNECTOR
GAS VALVE
Adjust Temperature Rise
NOTE: Blower door must be installed when taking temperature
rise reading. Leaving blower door off will result in incorrect
temperature measurements.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in:
SOverheating the heat exchangers or condensing
flue gases in heat exchanger areas not designed
for condensate
SShortened furnace life
SComponent damage
Temperature rise must be within limits specified on furnace
rating plate. Recommended operation is at midpoint of rise
range or slightly above.
CAUTION
!
Furnace must operate within ranges of temperature rise
specified on the furnace rating plate. When setup switch SW1-4
is ON, operation will be near the high end of the rise range for
improved comfort.
Determine air temperature rise as follows:
1. Place thermometers in return and supply ducts as near
furnace as possible. Be sure thermometers do not see
heat exchanger so that radiant heat does not affect
readings. This practice is particularly important with
straight-run ducts.
2. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
NOTE: Temperature rise can be determined for Minimum Heat,
Intermediate Heat and Maximum Heat operation by locking the
furnace in each mode of operation. The mode of operation is
based on the position of Set-up switch SW1-2 and SW4-2 on
the furnace control board.
The furnace is capable of automatically providing proper airflow
to maintain the temperature rise within the range specified on
furnace rating plate. If temperature rise is outside this range,
proceed as follows:
a. Check gas input for Minimum, Intermediate, and
Maximum heat operation.
b. Check derate for altitude if applicable.
c. Check all return and supply ducts for excessive
restrictions causing static pressure greater than 0.5-in.
w.c.
d. Ensure Min/Int Rise Adjust switch SW1−3 on furnace
control is in ON position when a bypass humidifier is
used. (See Figure 3 for switch location.)
e. Check Troubleshooting Guide for Variable−Speed Step
Modulating Condensing Furnaces.
f. Verify correct model plug is installed.
To lock the furnace in Minimum Heat:
1. Turn SW1−2 ON at the furnace control. Set up switch
SW4−2 must be OFF.
2. Connect a jumper across R and W/W1 at the thermostat
terminals at the furnace control.
3. Allow the burners to ignite and the blower to turn on.
4. Allow the supply temperature to stabilize and verify the
proper rise range.
If the temperature rise is too high or too low in Minimum
Heat:
1. Remove jumpers from R and W/W1.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 9
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of Set up switch SW1−3. When set to
ON, airflow is raised 18% for Minimum Heat and for
Intermediate Heat. Factory default position is OFF.
5. Turn 115 VAC power on.
6. Re−check Minimum Heat Temperature Rise.
To lock the furnace in Intermediate Heat:
1. Turn SW1−2 OFF and SW4−2 ON at the furnace control.
2. Connect a jumper across R and W/W1 at the thermostat
terminals at the furnace control.
3. Allow the burners to ignite and the blower to turn on.
4. Allow the supply temperature to stabilize and verify the
proper rise range.
If the temperature rise is too high or too low in Intermediate
Heat:
1. Remove jumpers from R and W/W1.
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of Set up switch SW1−3. When set to
ON, airflow is raised 18% for Minimum Heat and for
Intermediate Heat. Factory default position is OFF.
5. Turn 115 VAC power on.
6. Re−check Intermediate Heat Temperature Rise .
To lock the furnace in Maximum Heat:
1. Connect a jumper across R and W/W1 and W2 at the
thermostat terminals at the furnace control.
2. Allow the burners to ignite and the blower to turn on.
3. Allow the supply temperature to stabilize and verify the
proper rise range.
If the temperature rise is too high or too low in Maximum
Heat:
1. Remove jumpers from R and W/W1 and W2.
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of Set up switch SW1−4. When set to
OFF, and SW1−3 is set to OFF, airflow is raised 10% for
Minimum Heat, 7.5% for Intermediate Heat and 17.5%
for Maximum Heat. Factory default position is ON. If
SW1−3 is ON and SW1−4 is OFF, airflow is raised 18%
for Minimum and Intermediate heat and 10% for
Maximum Heat.
5. Turn 115 VAC power on.
6. Re−check Maximum Heat Temperature Rise.
After the temperature rise has been verified:
1. Remove jumpers from thermostat terminals.
2. Allow the blower off delay to complete.
3. Turn Set up switches SW1−2 and SW4−2 to the OFF
position unless two−stage thermostat operation is
desired. (See Figure 4)
4. Proceed to “Adjust Blower Off Delay” or install blower
door if complete.
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Reinstall manifold pressure tap plug in gas valve to
prevent gas leak.
!WARNING
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace
life.
Recheck temperature rise. It must be within limits specified
on the rating plate. Recommended operation is at the
mid−point of rise range or slightly above.
CAUTION
!
Adjust Blower Off Delay (Heat Mode)
a. Remove blower door if installed.
b. Turn Dip switch SW−7 or SW−8 ON or OFF for
desired blower off delay. (See Table 2, Figure 3 and
Figure 4)
Table 2 Blower Speed Taps
DESIRED HEATING MODE
BLOWER OFF DELAY
(SEC.)
SETUP SWITCH POSITION
SW1-7 SW1-8
90 OFF OFF
120 ON OFF
150 OFF ON
180 ON ON
Adjust Cooling Airflow −High−Speed and
Low−Speed Cooling
The ECM blower can be adjusted for a range of airflows for
low−speed or high−speed cooling. See Table 3 −Airflow
Switch Table, Table 6 −Air Delivery −CFM (with Filter) and
Figure 4. Furnace Setup Switches and Descriptions.
Depending on the model size, the cooling airflow can be
adjusted from 1.5 tons to 6 tons of nominal cooling based on
350 CFM ton.
NOTE: 6 ton airflow will truncate at 2200 CFM on applicable
models.
The high−speed or single−speed cooling airflow is adjusted by
turning setup switches SW2−1, SW2−2 and SW2−3 either ON
or OFF. Select the required airflow from Table 6. Table 6 is
based on 350 CFM per ton. For other CFM per ton setup switch
selections, see Table 3, Figure 4 and Figure 15.
The Continuous Fan airflow selection via setup switches SW3
is also the airflow for low−speed cooling when the furnace is
used with a two−speed cooling or heat pump unit. Adjust the
Continuous Fan CFM setup switches SW3 to match the airflow
required for low−speed cooling. Select the required airflow from
Table 6 and Figure 4.
NOTE: The airflow selected via SW3 (low−speed cooling
airflow) cannot exceed the airflow selected via SW2
(high−speed cooling airflow). For other CFM per ton setup
switch selections, see Table 3 and Figure 4.
NOTE: The airflow settings for SW2 and SW3 selections are
the same, EXCEPT for the default values. (See Table 6)
For a complete explanation of cooling airflow, refer to the
section titled “Sequence of Operation.”
Adjust Continuous Fan Airflow/Low Speed
Cooling Airflow
NOTE: When the furnace is used with a two−speed cooling or
heat pump unit, the airflow selected for Continuous Fan via
setup switch SW3 will also be the airflow used for low−speed
cooling, and vice versa.
NOTE: When the furnace is used with a two−speed cooling or
heat pump unit, adjust the Continuous Fan CFM setup
switches SW3 to match the airflow required for low−speed
cooling.
Select the required Continuous Fan airflow using setup
switches SW3 as shown in Table 3, Figure 4 and Figure 15.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
10 440 04 4201 03
Figure 4 Furnace Setup Switch Description
A11575
ESUFONOITPIRCSEDNOITISOPLAMRONEMANHCTIWSHCTIWSPUTES
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.
TONti Mii HtdIt ditHt
Furnace Setup Switch Description
SW1-3 Min/Int Heat Rise
Adjustment OFF
T
urn
ON
t
o
i
ncrease
Mi
n
i
mum
H
ea
t
an
d
I
n
t
erme
di
a
t
e
H
ea
t
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
Bl
ower
Off
D
e
l
ay t
i
me – a
dj
usta
bl
e 90 secon
d
s 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
p
ressure
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
123
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
123
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.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 11
Table 3 Airflow Switch Table
OOOOOOOOO
321
N321 N 321N 321N 321N 321N 321N 321N 321N
060-14
080-14
060-20
080-20
100-22
120-22
OOOOOOOOO
321
N321 N 321N 321N 321N 321N 321N 321N 321N
060-14
080-14
060-20
080-20
100-22
120-22
OOOOOOOOO
321
N321 N 321N 321N 321N 321N 321N 321N 321N
060-14
080-14
060-20
080-20
100-22
120-22
OOOOOOOOO
321
N321 N 321N 321N 321N 321N 321N 321N 321N
060-14
080-14
060-20
080-20
100-22
120-22
1860
1860
1116
1116
976
976
1200
1200
1860
2100
1488
1860
2100
930
744
930
1116
1302
1488
744
744
930
1116
1302
1860
744
744
930
1116
1302
1488
1860
1860
1860
744
744
930
1116
1302
1488
1860
1860
1302
1302
1302
558
558
744
930
1116
1302
558
558
744
930
1116
1302
1302
1627
1953
NOMINAL AIRFLOW BASED ON 370 CFM/TON (SW1-5 = ON, SW4-3 = ON)
Model Size
SW2 Clg Default
SW3 CF Default
COOLING (SW2) AND CONTINUOUS FAN (SW3) AIRFLOW: SET-UP SWITCH POSITIONS
1302
1627
1953
1627
814
651
814
976
1139
1302
1627
651
651
814
976
1139
1627
651
651
814
976
1139
1302
1627
1627
1627
651
651
814
976
1139
1302
1627
1627
1139
1139
1139
488
488
651
814
976
1139
488
488
651
814
976
1139
1139
2000
2100
NOMINAL AIRFLOW BASED ON 325 CFM/TON (SW1-5 = OFF, SW4-3 = ON)
Model Size
SW2 Clg Default
SW3 CF Default
COOLING (SW2) AND CONTINUOUS FAN (SW3) AIRFLOW: SET-UP SWITCH POSITIONS
1600
2000
2100
2000
1000
800
1000
1200
1400
1600
2000
800
800
1000
1200
1400
2000
800
800
1000
1200
1400
1600
2000
2000
2000
800
800
1000
1200
1400
1600
2000
2000
1400
1400
1400
600
600
800
1000
1200
1400
600
600
800
1000
1200
1400
1400
1400
1750
2100
NOMINAL AIRFLOW BASED ON 400 CFM/TON (SW1-5 = ON, SW4-3 = OFF)
Model Size
SW2 Clg Default
SW3 CF Default
COOLING (SW2) AND CONTINUOUS FAN (SW3) AIRFLOW: SET-UP SWITCH POSITIONS
1750
875
700
875
1050
1225
1750
700
700
875
1050
1225
1400
1750
2100
1750
700
700
875
1050
1225
1400
1750
1750
1750
700
700
875
1050
1225
1400
1750
1750
1050
525
525
700
875
1050
1225
1225
1225
NOMINAL AIRFLOW BASED ON 350 CFM/TON (Factory Default - SW1-5 = OFF, SW4-3 = OFF)
Model Size
SW2 Clg Default
SW3 CF Default
COOLING (SW2) AND CONTINUOUS FAN (SW3) AIRFLOW: SET-UP SWITCH POSITIONS
1050
525
525
700
875
1050
1225
1225
1225
L11F092
Adjust Thermostat Heat Anticipator
a. Mechanical thermostat. Set thermostat heat
anticipator to match the amp. draw of the electrical
components in the R−W/W1 circuit. Accurate amp.
draw readings can be obtained at the wires normally
connected to thermostat subbase terminals, R and W.
The thermostat anticipator should NOT be in the
circuit while measuring current.
(1.) Set SW1−2 switch on furnace control board to
ON.
(2.) Remove thermostat from subbase or from wall.
(3.) Connect an amp. meter as shown in Figure 5
across the R and W subbase terminals or R and
W wires at wall.
(4.) Record amp. draw across terminals when
furnace is in minimum heat and after blower
starts.
(5.) Set heat anticipator on thermostat per thermostat
instructions and install on subbase or wall.
(6.) Turn SW1−2 switch OFF.
(7.) Install blower door.
b. Electronic thermostat: Set cycle rate for three cycles
per hr.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
12 440 04 4201 03
Figure 5 Amp. Draw Check with Ammeter
A96316
R Y W G
10 TURNS
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
(ANITICIPATOR, CLOCK, ETC.,
MUST BE OUT OF CIRCUIT.)
HOOK-AROUND
AMMETER
EXAMPLE: 5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
= 0.5 AMPS FOR THERMOSTAT
ANTICIPATOR SETTING
FROM UNIT 24-V
CONTROL TERMINALS
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all
checked in the Start−up procedure section as part of normal
operation.
1. Check Main Limit Switch
This control shuts off combustion system and energizes
air−circulating blower motor, if furnace overheats. By
using this method to check limit control, it can be
established that limit is functioning properly and will
operate if there is a restricted return−air supply or motor
failure. If limit control does not function during this test,
cause must be determined and corrected.
a. Run furnace for at least five minutes.
b. Gradually block off return air with a piece of
cardboard or sheet metal until the limit trips.
c. Unblock return air to permit normal circulation.
d. Burners will re−light when furnace cools down.
2. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 115−v power to furnace.
b. Disconnect inducer motor lead wires from wire
harness.
c. Turn on 115−v power to furnace.
d. Set thermostat to “call for heat” and wait 1 minute.
When pressure switch is functioning properly, hot
surface igniter should NOT glow and control
diagnostic light flashes a status code 3. If hot surface
igniter glows when inducer motor is disconnected,
shut down furnace immediately.
e. Determine reason pressure switch did not function
properly and correct condition.
f. Turn off 115−v power to furnace.
g. Reconnect inducer motor wires, replace blower door,
and turn on 115−v power.
h. Blower will run for 90 seconds before beginning the
call for heat again.
i. Furnace should ignite normally.
Checklist
1. Put away tools and instruments. Clean up debris.
2. Verify that switches SW1−1 and SW1−6 are OFF and
other setup switches are set as desired. Verify that
switches SW1−7 and SW1−8 for the blower OFF DELAY
are set as desired per Table 2.
3. Verify that blower and control doors are properly
installed.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s
instructions.
6. Review Home Owner’s Information with owner.
7. Attach literature packet to furnace.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 13
Table 4 Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
TO BE USED WITH MODULATING FURNACES EXCEPT THE (F/G)9MAC0602120
SAGLARUTANFOYTIVARGCIFICEPSSAG.GVA
HEATVALUE0.580.600.620.64
AT ALTITUDE Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft) No. Max/Min No. Max/Min No. Max/Min No. Max/Min
900 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55
092543 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50
(0) 950 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.60 43 3.7 /0.60
975 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55 43 3.6 /0.55
to 1000 44 3.5 /0.55 44 3.6 /0.60 44 3.8 /0.60 43 3.4 /0.55
1025 44 3.3 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60
2000 1050 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55 44 3.5 /0.55
(610) 1075 45 3.7 /0.60 45 3.8 /0.60 44 3.3 /0.50 44 3.4 /0.55
1100 46 3.7 /0.60 46 3.8 /0.60 45 3.8 /0.60 44 3.2 /0.50
U.S.A. 800 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55 42 3.7 /0.60
2001 (611) 825 43 3.8 /0.60 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
to 850 43 3.6 /0.60 43 3.7 /0.60 42 3.2 /0.50 42 3.3 /0.55
3000 (914) 875 43 3.4 /0.55 43 3.5 /0.55 43 3.7 /0.60 43 3.8 /0.60
900 44 3.7 /0.60 44 3.8 /0.60 43 3.5 /0.55 43 3.6 /0.55
Canada 925 44 3.5 /0.55 44 3.6 /0.60 44 3.8 /0.60 43 3.4 /0.55
2001 (611) 950 44 3.3 /0.55 44 3.4 /0.55 44 3.6 /0.55 44 3.7 /0.60
to 975 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55
4500 (1372) 1000 46 3.8 /0.60 45 3.8 /0.60 44 3.2 /0.50 44 3.3 /0.55
775 42 3.3 /0.55 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.60
3001 800 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55
(915) 825 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50
850 44 3.8 /0.60 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60
875 44 3.6 /0.60 44 3.7 /0.60 43 3.4 /0.55 43 3.5 /0.55
4000 900 44 3.4 /0.55 44 3.5 /0.55 44 3.7 /0.60 44 3.8 /0.60
(1219) 925 44 3.2 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
950 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55
750 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55
4001 775 43 3.7 /0.60 43 3.8 /0.60 42 3.3 /0.50 42 3.4 /0.55
(1220) 800 43 3.5 /0.55 43 3.6 /0.60 43 3.7 /0.60 43 3.8 /0.60
825 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.60
850 44 3.5 /0.55 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55
5000 875 44 3.3 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60
(1524) 900 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55
925 46 3.8 /0.60 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.55
725 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55 42 3.5 /0.55
5001 750 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55
(1525) 775 43 3.4 /0.55 43 3.5 /0.55 43 3.7 /0.60 43 3.8 /0.60
800 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55
825 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60
6000 850 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.60
(1829) 875 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55
900 46 3.7 /0.60 46 3.8 /0.60 45 3.8 /0.60 44 3.2 /0.50
675 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.60 42 3.8 /0.60
6001 700 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
(1830) 725 43 3.6 /0.60 43 3.7 /0.60 43 3.8 /0.60 42 3.3 /0.50
750 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60
775 44 3.6 /0.60 44 3.7 /0.60 43 3.4 /0.55 43 3.5 /0.55
7000 800 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.60 44 3.7 /0.60
(2133) 825 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55 44 3.5 /0.55
850 46 3.8 /0.60 45 3.8 /0.60 44 3.2 /0.50 44 3.3 /0.55
(TABULATED DATA BASED ON 20,000 BTUH MAX-HEAT / 8,000 BTUH MIN-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
ft (m)
U.S.A. and CanadaU.S.A. and CanadaU.S.A. Only
to
U.S.A. Only
to
U.S.A. Only
to
U.S.A. Only
to
MODULATING FURNACE
A11251A

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
14 440 04 4201 03
Table 4 (Cont.) Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
TO BE USED WITH MODULATING FURNACES EXCEPT THE (F/G)9MAC0602120
SAGLARUTANFOYTIVARGCIFICEPSSAG.GVA
HEATVALUE0.580.600.620.64
AT ALTITUDE Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft) No. Max/Min No. Max/Min No. Max/Min No. Max/Min
(TABULATED DATA BASED ON 20,000 BTUH MAX-HEAT / 8,000 BTUH MIN-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
ft (m)
650 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.60 42 3.7 /0.60
7001 675 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55
(2134) 700 43 3.5 /0.55 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50
725 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.60
750 44 3.5 /0.55 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55
8000 775 44 3.3 /0.55 44 3.4 /0.55 44 3.5 /0.55 44 3.7 /0.60
(2438) 800 45 3.8 /0.60 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55
825 46 3.7 /0.60 46 3.8 /0.60 45 3.8 /0.60 44 3.2 /0.50
625 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55 42 3.7 /0.60
8001 650 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55
(2439) 675 43 3.5 /0.55 43 3.6 /0.60 43 3.7 /0.60 42 3.2 /0.50
700 44 3.7 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55
725 44 3.5 /0.55 44 3.6 /0.60 44 3.7 /0.60 44 3.8 /0.60
9000 750 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
(2743) 775 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
9001 600 42 3.3 /0.55 42 3.4 /0.55 42 3.6 /0.55 42 3.7 /0.60
(2744) 625 43 3.7 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.4 /0.55
650 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60
675 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55
10000 700 44 3.4 /0.55 44 3.5 /0.55 44 3.7 /0.60 44 3.8 /0.60
(3048) 725 44 3.2 /0.50 44 3.3 /0.55 44 3.4 /0.55 44 3.5 /0.55
* Orifice numbers shown in BOLD are factory-installed.
U.S.A. Only
to
U.S.A. Only
to
U.S.A. Only
to
MODULATING FURNACE
A11251B

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 15
Table 5 Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
TO BE USED WITH MODULATING FURNACES (F/G)9MAC0602120 FURNACE ONLY
AVG. GAS SPECIFIC GRAVITY OF NATURAL GAS
HEAT VALUE 0.58 0.60 0.62 0.64
AT ALTITUDE Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft) No. Max/Min No. Max/Min No. Max/Min No. Max/Min
900 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
0 925 43 3.7 /0.55 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.50
(0) 950 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60
975 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55
to 1000 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60 43 3.5 /0.55
1025 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.8 /0.60
2000 1050 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
(610) 1075 45 3.8 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
1100 46 3.8 /0.60 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50
U.S.A. 800 42 3.4 /0.55 42 3.5 /0.55 42 3.7 /0.55 42 3.8 /0.60
2001 (611) 825 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.6 /0.55
to 850 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55
3000 (914) 875 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60
900 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55
Canada 925 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55
2001 (611) 950 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60
to 975 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55 44 3.6 /0.55
4500 (1372) 1000 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
775 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55 42 3.7 /0.60
3001 800 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
(915) 825 43 3.6 /0.55 43 3.7 /0.60 42 3.2 /0.50 42 3.3 /0.50
850 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55 43 3.8 /0.60
875 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55 43 3.6 /0.55
4000 900 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60 43 3.4 /0.55
(1219) 925 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
950 45 3.8 /0.60 44 3.2 /0.50 44 3.4 /0.55 44 3.5 /0.55
750 42 3.3 /0.50 42 3.4 /0.55 42 3.6 /0.55 42 3.7 /0.55
4001 775 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55
(1220) 800 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50
825 44 3.8 /0.60 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60
850 44 3.6 /0.55 44 3.7 /0.60 43 3.4 /0.55 43 3.5 /0.55
5000 875 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.8 /0.60
(1524) 900 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55 44 3.6 /0.55
925 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
725 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55
5001 750 43 3.7 /0.60 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55
(1525) 775 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60 42 3.2 /0.50
800 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55
825 44 3.5 /0.55 44 3.7 /0.55 44 3.8 /0.60 43 3.4 /0.55
6000 850 44 3.3 /0.50 44 3.4 /0.55 44 3.6 /0.55 44 3.7 /0.60
(1829) 875 45 3.8 /0.60 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55
900 46 3.8 /0.60 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50
675 42 3.5 /0.55 42 3.6 /0.55 42 3.7 /0.60 42 3.8 /0.60
6001 700 42 3.2 /0.50 42 3.3 /0.50 42 3.5 /0.55 42 3.6 /0.55
(1830) 725 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.50
750 43 3.4 /0.55 43 3.5 /0.55 43 3.7 /0.55 43 3.8 /0.60
775 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55
7000 800 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60
(2133) 825 44 3.2 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
850 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
U.S.A. Only
to
U.S.A. Only
to
ft (m)
U.S.A. and CanadaU.S.A. and CanadaU.S.A. Only
to
U.S.A. Only
to
(TABULATED DATA BASED ON 20,200 BTUH MAX-HEAT / 8,000 BTUH MIN-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
L11F100A

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
16 440 04 4201 03
Table 5 (Cont.) Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
TO BE USED WITH MODULATING FURNACES (F/G)9MAC0602120 FURNACE ONLY
AVG. GAS SPECIFIC GRAVITY OF NATURAL GAS
HEAT VALUE 0.58 0.60 0.62 0.64
AT ALTITUDE Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft) No. Max/Min No. Max/Min No. Max/Min No. Max/Min
ft (m)
(TABULATED DATA BASED ON 20,200 BTUH MAX-HEAT / 8,000 BTUH MIN-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
650 42 3.4 /0.55 42 3.6 /0.55 42 3.7 /0.60 42 3.8 /0.60
7001 675 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
(2134) 700 43 3.6 /0.55 43 3.7 /0.60 42 3.2 /0.50 42 3.3 /0.50
725 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55 43 3.7 /0.60
750 44 3.6 /0.55 44 3.7 /0.60 43 3.4 /0.55 43 3.5 /0.55
8000 775 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60
(2438) 800 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55
825 46 3.8 /0.60 45 3.7 /0.60 44 3.2 /0.50 44 3.3 /0.50
625 42 3.4 /0.55 42 3.5 /0.55 42 3.7 /0.55 42 3.8 /0.60
8001 650 42 3.2 /0.50 42 3.3 /0.50 42 3.4 /0.55 42 3.5 /0.55
(2439) 675 43 3.6 /0.55 43 3.7 /0.60 43 3.8 /0.60 42 3.2 /0.50
700 44 3.8 /0.60 43 3.4 /0.55 43 3.6 /0.55 43 3.7 /0.55
725 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60 43 3.4 /0.55
9000 750 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.7 /0.55
(2743) 775 45 3.8 /0.60 44 3.2 /0.50 44 3.3 /0.50 44 3.4 /0.55
9001 600 42 3.4 /0.55 42 3.5 /0.55 42 3.6 /0.55 42 3.8 /0.60
(2744) 625 43 3.8 /0.60 42 3.2 /0.50 42 3.3 /0.55 42 3.5 /0.55
650 43 3.5 /0.55 43 3.6 /0.55 43 3.8 /0.60 42 3.2 /0.50
675 44 3.8 /0.60 43 3.4 /0.55 43 3.5 /0.55 43 3.6 /0.55
10000 700 44 3.5 /0.55 44 3.6 /0.55 44 3.7 /0.60 44 3.8 /0.60
(3048) 725 44 3.3 /0.50 44 3.4 /0.55 44 3.5 /0.55 44 3.6 /0.55
* Orifice numbers shown in BOLD are factory-installed.
U.S.A. Only
to
U.S.A. Only
to
U.S.A. Only
to
L11F100B

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 17
Table 6 COOLING4AND HEATING AIR DELIVERY - CFM (Bottom Return5with Filter)
(SW1-5 and SW4-3 set to OFF, except as indicated. See notes 1 and 2)
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
060-14
Clg Default: OFF OFF OFF 1060 1070 1080 1080 1075 1065 1050 1035 1025 1010
CF Default: OFF OFF OFF 545 530 520 525 510 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 545 530 520 525 510 See note 4
OFF ON OFF 710 710 710 695 690 See note 4
OFF ON ON 875 880 890 895 895 890 885 880 870 855
ON OFF OFF 1060 1070 1080 1080 1075 1065 1050 1035 1025 1010
ON OFF ON 1235 1240 1250 1255 1255 1250 1230 1190 1155 1115
ON ON OFF 1235 1240 1250 1255 1255 1250 1230 1190 1155 1115
ON ON ON 1235 1240 1250 1255 1255 1250 1230 1190 1155 1115
Clg SW2: Maximum Clg Airflow 21425 1425 1405 1370 1335 1300 1260 1225 1190 1155
Heating
(SW1)
Maximum Heat Airflow 31075 1085 1095 1095 1090 1080 1065 1050 1035 1020
Intermediate Heat Airflow 3535 515 505 515 495 See note 4
Minimum Heat Airflow 3420 410 415 400 380 See note 4
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
060−20
Clg Default: OFF OFF OFF 1735 1735 1725 1715 1700 1685 1665 1650 1625 1605
CF Default: OFF OFF OFF 545 530 520 525 510 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 540 525 525 520 540 See note 4
OFF ON OFF 680 725 725 720 720 See note 4
OFF ON ON 925 915 910 895 900 890 875 865 860 855
ON OFF OFF 1070 1075 1080 1070 1080 1075 1055 1045 1030 1020
ON OFF ON 1215 1245 1235 1220 1220 1210 1200 1195 1185 1175
ON ON OFF 1380 1385 1395 1390 1395 1390 1380 1365 1355 1340
ON ON ON 1735 1735 1725 1715 1700 1685 1665 1650 1625 1605
Clg SW2: Maximum Clg Airflow 21955 1950 1940 1925 1905 1885 1855 1815 1745 1685
Heating
(SW1)
Maximum Heat Airflow 31080 1085 1095 1090 1095 1085 1070 1055 1045 1030
Intermediate Heat Airflow 3685 725 730 725 730 See note 4
Minimum Heat Airflow 3560 555 555 550 565 See note 4

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
18 440 04 4201 03
Table 6 (Cont.) COOLING4AND HEATING AIR DELIVERY - CFM (Bottom Return5with Filter)
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
080-14
Clg Default: OFF OFF OFF 1055 1065 1080 1075 1065 1050 1045 1035 1025 1005
CF Default: OFF OFF OFF 520 505 505 495 490 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 520 505 505 495 490 See note 4
OFF ON OFF 665 685 680 660 665 See note 4
OFF ON ON 885 895 905 900 900 895 885 875 860 845
ON OFF OFF 1055 1065 1080 1075 1065 1050 1045 1035 1025 1005
ON OFF ON 1245 1245 1255 1255 1260 1255 1250 1235 1220 1185
ON ON OFF 1245 1245 1255 1255 1260 1255 1250 1235 1220 1185
ON ON ON 1245 1245 1255 1255 1260 1255 1250 1235 1220 1185
Clg SW2: Maximum Clg Airflow 21520 1485 1450 1415 1375 1335 1300 1265 1225 1190
Heating
(SW1)
Maximum Heat Airflow 31520 1485 1450 1415 1375 1335 1300 1265 1225 1190
Intermediate Heat Airflow 3755 745 755 755 765 See note 4
Minimum Heat Airflow 3620 625 630 620 610 See note 4
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
080−20
Clg Default: OFF OFF OFF 1745 1755 1755 1760 1755 1750 1745 1725 1705 1685
CF Default: OFF OFF OFF 700 710 750 725 750 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 700 710 750 725 750 See note 4
OFF ON OFF 830 860 870 890 960 See note 4
OFF ON ON 1045 1045 1060 1070 1070 1070 1095 1090 1080 1070
ON OFF OFF 1215 1220 1245 1240 1235 1235 1225 1220 1235 1235
ON OFF ON 1370 1370 1390 1390 1400 1395 1400 1390 1390 1385
ON ON OFF 1745 1755 1755 1760 1755 1750 1745 1725 1705 1685
ON ON ON 1745 1755 1755 1760 1755 1750 1745 1725 1705 1685
Clg SW2: Maximum Clg Airflow 21920 1920 1945 1945 1945 1960 1950 1940 1915 1900
Heating
(SW1)
Maximum Heat Airflow 31340 1355 1370 1385 1380 1385 1400 1400 1385 1380
Intermediate Heat Airflow 3780 810 835 840 845 See note 4
Minimum Heat Airflow 3595 595 600 595 605 See note 4

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 19
Table 6 (Cont.) COOLING4AND HEATING AIR DELIVERY - CFM (Bottom Return5with Filter)
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
100-22
Clg Default: OFF OFF OFF 1820 1825 1840 1845 1840 1835 1825 1805 1780 1770
CF Default: OFF OFF OFF 750 740 745 730 715 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 750 740 745 730 715 See note 4
OFF ON OFF 900 900 915 910 905 See note 4
OFF ON ON 1070 1075 1095 1095 1090 1085 1095 1080 1065 1070
ON OFF OFF 1280 1285 1305 1305 1310 1305 1295 1300 1290 1285
ON OFF ON 1440 1445 1465 1465 1470 1485 1480 1485 1475 1460
ON ON OFF 1820 1825 1840 1845 1840 1835 1825 1805 1780 1770
ON ON ON 2135 2140 2140 2135 2140 2130 2115 2100 2070 2015
Clg SW2: Maximum Clg Airflow 22160 2165 2175 2170 2160 2150 2135 2120 2065 2020
Heating
(SW1)
Maximum Heat Airflow 31570 1575 1595 1595 1600 1605 1600 1600 1590 1575
Intermediate Heat Airflow 3950 955 965 975 970 See note 4
Minimum Heat Airflow 3755 745 750 735 720 See note 4
Unit Size Clg/CF Switch Settings External Static Pressure (ESP)
SWx-3 SWx-2 SWx-1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
120-22
Clg Default: OFF OFF OFF 1850 1855 1860 1855 1850 1830 1805 1775 1750 1730
CF Default: OFF OFF OFF 930 925 915 900 885 See note 4
Cooling (SW2)
Cont Fan (SW3)
OFF OFF ON 765 745 740 705 680 See note 4
OFF ON OFF 930 925 915 900 885 See note 4
OFF ON ON 1095 1100 1110 1105 1085 See note 4
ON OFF OFF 1265 1255 1265 1280 1275 1285 1270 1260 1250 1230
ON OFF ON 1465 1455 1470 1465 1465 1470 1455 1450 1435 1415
ON ON OFF 1850 1855 1860 1855 1850 1830 1805 1775 1750 1730
ON ON ON 2200 2200 2200 2190 2185 2170 2145 2085 1990 1890
Clg SW2: Maximum Clg Airflow 22200 2200 2200 2190 2185 2170 2145 2085 1990 1890
Heating
(SW1)
Maximum Heat Airflow 31815 1820 1825 1820 1815 1795 1775 1745 1720 1700
Intermediate Heat Airflow 31095 1100 1110 1105 1085 See note 4
Minimum Heat Airflow 3905 900 890 875 855 See note 4
1. Nominal 350 CFM/ton cooling airflow is delivered with SW1−5 and SW4−3 set to OFF.
Set SW1−5 to ON for nominal 400 CFM/ton (+15% airflow).
Set SW4−3 to ON for nominal 325 CFM/ton (−7% airflow).
Set both SW1−5 and SW4−3 to ON for nominal 370 CFM/ton (+7% airflow).
The above adjustments in airflow are subject to motor horspower range/capacity.
2. Maximum cooling airflow is achieved when switches SW2−1, SW2−2, SW2−3 and SW1−5 are set to ON, and SW4−3 is set to OFF.
3. All heating CFM’s are when low/medium heat rise adjustment switch (SW1−3) and comfort/efficiency adjustment switch (SW1−4) are both
set to OFF.
4. Ductwork must be sized for high−heating CFM within the operational range of ESP. Operation within the blank areas of the chart is not
recommended because high−heat operation will be above 1.0 ESP.
5. All airflows on 21” casing size furnaces are 5% less on side return only installations.
6. Side returns for 24.5” casing sizes require two sides, or side and bottom, to allow sufficient airflow at the return of the furnace.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
20 440 04 4201 03
Table 7 Gas Rate (CU ft./hr)
SECONDS G
FOR 1 REVOLUTION
SIZE OF TEST DIAL SECONDS
FOR 1 REVOLUTION
SIZE OF TEST DIAL
1 Cu Ft. 2 Cu Ft. 5 Cu Ft. 1 Cu Ft. 2 Cu Ft. 5 Cu Ft.
10 360 720 1800 50 72 144 360
11 327 655 1636 51 71 141 355
12 300 600 1500 52 69 138 346
13 277 555 1385 53 68 136 340
14 257 514 1286 54 67 133 333
15 240 480 1200 55 65 131 327
16 225 450 1125 56 64 129 321
17 212 424 1059 57 63 126 316
18 200 400 1000 58 62 124 310
19 189 379 947 59 61 122 305
20 180 360 900 60 60 120 300
21 171 343 857 62 58 116 290
22 164 327 818 64 56 112 281
23 157 313 783 66 54 109 273
24 150 300 750 68 53 106 265
25 144 288 720 70 51 103 257
26 138 277 692 72 50 100 250
27 133 267 667 74 48 97 243
28 129 257 643 76 47 95 237
29 124 248 621 78 46 92 231
30 120 240 600 80 45 90 225
31 116 232 581 82 44 88 220
32 113 225 563 84 43 86 214
33 109 218 545 86 42 84 209
34 106 212 529 88 41 82 205
35 103 206 514 90 40 80 200
36 100 200 500 92 39 78 196
37 97 195 486 94 38 76 192
38 95 189 474 96 38 75 188
39 92 185 462 98 37 74 184
40 90 180 450 100 36 72 180
41 88 176 439 102 35 71 178
42 86 172 429 104 35 69 173
43 84 167 419 106 34 68 170
44 82 164 409 108 33 67 167
45 80 160 400 110 33 65 164
46 78 157 391 112 32 64 161
47 76 153 383 116 31 62 155
48 75 150 375 120 30 60 150
49 73 147 367