6
443 06 2403 01
Specifications subject to change without notice.
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit
damage, fire, personal injury or death.
DO NOT use the back or sides of the furnace for
return
−
air duct connections in downflow position, as limit
switch cycling will occur.
!
WARNING
4. Remove bottom closure panels from both furnaces. (See
Figure 4)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Pull front panel forward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall bottom front panel.
f. Stand furnaces upright.
5. Apply 2 factory
−
supplied foam strips to mating side of
each furnace. Locate strips equal distance from top and
bottom as shown in Figure 5. Trim off excess material.
6. Remove 7/8
−
in. diameter accessory hole knock
−
outs in
blower compartment from mating sides of furnaces. (See
Bottom
Closure Panel
Bottom Filler Panel
Figure 4
−
Removing Bottom Closure Panel
Figure 5
−
Location of Foam Strips
7. Insert a plastic snap bushing through the 7/8
−
in.
knock
−
out from the outside of the casing.
8. Bend or remove the supply flanges as required for
upflow or downflow installation. Refer to the furnace
installation instructions for complete details.
9. Position furnaces against each other on return air
plenum, supply air plenum or evaporator coil casing.
Adjust and shim each furnace to align 7/8
−
in. diameter
holes in both furnaces.
10. Drill two 1/8
−
in. holes, approximately 1 in. (25 mm)below
discharge flange, from inside top of discharge opening
and through both furnaces. (See Figure 6) Drill two
1/8
−
in. holes, approximately 1 in. (25 mm)below return
air flange, from inside top of return air opening and
through both furnaces. (See Figure 7 as an example.)
11. Drive 1 factory
−
supplied screw through each hole and
tighten until furnaces are secure and foam strips have
sealed gap between furnaces.
12. Connect return
−
and supply
−
air ducts to furnaces. Seal
duct connections to prevent air leakage.
13. Move 115
−
v junction box JB in RH furnace (as viewed
from the upflow position) from left
−
hand side to
right
−
hand side. Refer to furnace installation instructions
for complete details.
14. Go to PROCEDURE 2A for Single Stage Furnaces or
PROCEDURE 2B for Two
−
Stage Furnaces.
B. Upflow/Downflow, Back
−
to
−
Back Position
Refer to Figure 3 and Table 2 for appearance and dimensional
drawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See
2. Remove outer door and blower access door.
3. Remove bottom closure panels from both furnaces. (See
Figure 4)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Pull front panel forward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall bottom front panel.
f. Stand furnaces upright.
4. Applications
A02232
Figure 6
−
Attaching Furnaces Together at Discharge
Opening
a. For upflow applications:
Bottom return air usage is required as part of any
upflow return air configuration. If additional return air
is to enter 1 side of each furnace, in addition to
bottom return air, cut open 1 entire return
−
air
