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NOTE:
(Direct Vent/2-Pipe ONLY) vent pipe system has the
same diameter and same length as combustion air pipe as men-
tioned in section
″
Assembly of Combustion Air Pipe (Direct
Vent/2-Pipe system ONLY).
″
NOTE:
Do not count elbows or pipe sections in terminations or
within furnace (all elbows shown in Fig. 44 and Fig. 45 are not be
counted).
2. Determine location of vent pipe connection to inducer housing
as shown in Fig. 38 for application.
3. Install vent pipe grommet (factory-supplied in loose parts bag)
into selected furnace casing vent pipe hole. (See Fig. 44.)
4. Reposition elastomeric (rubber) inducer housing outlet cap
and clamp to appropriate unused inducer housing connection.
Tighten clamp.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage.
5. Be certain that mating surfaces of inducer housing connection
elastomeric (rubber) coupling, and 2-in. diameter vent pipe are
clean and dry. Assemble the elastomeric (rubber) vent cou-
pling (with 2 loose clamps) onto inducer housing connection.
Insert the 2-in. diameter vent pipe through the elastomeric
(rubber) coupling and fully into inducer housing connection
until it touches a stop inside the inducer housing outlet.
Tighten the screws on both clamps to 15-in-lb. of torque. pipe
to inducer housing. Tighten the clamp screws to 15 in.-lb. of
torque.
NOTE:
Starting at furnace, slope vent pipe a minimum of 1/4-in.
per linear ft with no sags between hangers.
Fig. 38—Combustion-Air and Vent Pipe
Connections
A05092
COMBUSTION-
AIR
COMBUSTION-
AIR
AIR
FLOW
VENT
VENT
VENT
AIR
FLOW
AIR
FLOW
AIR
FLOW
UPFLOW
DOWNFLOW
HORIZONTAL-LEFT DISCHARGE
HORIZONTAL-RIGHT DISCHARGE
Select 1 vent pipe connection and
1 combustion-air pipe connection.
COMBUSTION-
AIR
COMBUSTION-
AIR
COMBUSTION-
AIR
COMBUSTION-
AIR
VENT
VENT
VENT
NOTE:
Select 1 vent pipe connection and
1 combustion-air pipe connection.
NOTE:
* For Non-Direct Vent (1-Pipe) system, orient elbow so that its
opening faces down.
** For Non-Direct Vent (1-Pipe) system, orient elbow so that its
opening faces sideways.
† An external trap kit (see furnace product data sheet) must be used.
*
*
**
**
†
†
Table 11A—Furnace Setup Switch Description
SETUP
SWITCH
NO.
SWITCH
NAME
NORMAL
POSITION
DESCRIPTION
OF
USE
SW-1
Adaptive
Heat
Mode
OFF
When off, allows 2-stage operation with a
single-stage thermostat.
Turn on when using 2-stage
thermostat to allow Low Heat
operation when R to W/W1 closes
and High Heat operation when
R to W/W1 and W2 close.
SW-2
Blower
OFF
delay
ON or OFF
Control blower OFF
delay time. Used in
conjunction with SW-3.
See Table 9B.
SW-3
Blower
OFF
delay
ON or OFF
Control blower OFF
delay time. Used in
conjunction with SW-2.
See Table 9B.
Table 11B—Blower Off Delay Setup Switch (SW)
2–Stage Units with PSC Blower Motors
DESIRED HEATING MODE
BLOWER-OFF DELAY (SEC)
SETUP SWITCH
SW-2
SW-3
90
OFF
OFF
120
OFF
ON
150
ON
OFF
180
ON
ON
Fig. 39—Combustion-Air Inlet Pipe Assembly
Length of Straight Pipe Portion of
Combustion-Air Inlet Pipe Assembly (In.)
CASING WIDTH
A
17-1/2
8-1/2
±
1/2
21
10-1/2
±
1/2
24-1/2
12
±
1/2
A96211
FIELD-SUPPLIED
2-IN. DIAMETER
PVC PIPE
FIELD-SUPPLIED
2-IN. DIAMETER
PVC 90
°
ELBOW
COMBUSTION-AIR DISC
(FACTORY-SUPPLIED IN
LOOSE PARTS BAG)
A
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