NOTE: Standard and alternate locations can be combined (for
example, an installation may use the standard combustion air
intake location but use the alternate vent/flue location or vice
versa), if needed.
Edges of sheet metal holes may be sharp. Use gloves as
a precaution when removing hole plugs.
Alternate Vent/Flue Location
The alternate vent/flue location is the large hole directly in line
with the induced draft blower outlet. To use the alternate vent/flue
location, refer to the following steps and the "Alternate Vent/Flue
NOTE: Counterflow instructions follow the upflow instructions.
1. Remove and save the 4 screws securing the vent/flue
coupling to the furnace top panel.
Remove and save the 4 screws securing the vent/flue
coupling to the furnace base pan. Also remove the 3 screws
securing the furnace's internal vent/flue piping to the blower
Upflow and Counterflow Units
2. Loosen the worm gear hose clamps on the rubber elbow and
detach the rubber elbow from both the induced draft blower
and the vent/flue pipe.
3. Remove the vent/flue pipe from the furnace.
4. Cut the vent/flue pipe 3³⁄₄" (9.5 cm) from the flanged end of
the pipe. See "Vent/Flue Pipe Cuts" illustration.
NOTE: The section of pipe attached to the coupling will reach
through the side panel to the induced draft blower.
5. Discard remaining pipe and elbows.
Cut the vent/flue pipe 3³⁄₄" (9.5 cm) from the blower deck
coupling. See "Vent/Flue Pipe Cuts" illustration
Save vent/flue pipe attached to the blower deck coupling for
use in the alternate location.
Discard remaining pipe and elbows.
Vent/Flue Pipe Cuts
B. Cut location
C. 3 ³⁄₄ " (9.5 cm)
6. Remove the plastic plug from the alternate vent/flue location.
7. Relocate and install the plastic plug in the standard vent/flue
location (top cover).
Remove the plastic plug from the alternate vent/flue location.
Relocate and install the plastic plug in the standard vent/flue
location (base pan).
Plug remaining hole in the blower deck with the plastic plug
included in the drain kit bag.
Upflow and Counterflow Units
8. Insert the cut section of the vent/flue pipe and coupling into
the alternate vent/flue location.
9. Attach the vent/flue pipe and coupling to the induced draft
blower using a rubber coupling and worm gear hose clamps
provided in the drain kit bag.
10. Secure the coupling to the cabinet using the screws removed
in Step 1 or with field-supplied ³⁄₈" #8 self-drilling screws.
The rubber elbow is not designed to support a load.
When the rubber elbow is mounted externally to the
furnace cabinet, extreme care must be taken to adequately
support field-supplied vent/flue piping, as damage can
result in leaks causing bodily injury or death due to
exposure to flue gases, including carbon monoxide.
11. For upright installations, externally mount the rubber elbow to
the vent/flue coupling using a worm gear hose clamp.
12. Secure the field-supplied vent/flue piping to the rubber elbow
using a worm gear hose clamp.
NOTE: Use of the alternate vent/flue location for upright
installations, requires the drain trap to be installed on the
same side of the furnace as the flue pipe.
13. For horizontal installations, externally secure the field
supplied vent/flue pipe directly to the vent/flue coupling using
a PVC or ABS coupling or elbow.
Alternate Vent/Flue Location—Upflow
A. Vent/flue pipe
B. Screw locations (4)
C. Plastic plug—alternate vent/flue location
Alternate Vent/Flue Location—Counterflow/Upright
A. Plastic plug from drain kit bag
B. Vent/flue pipe
D. Rubber elbow
E. Induced draft
C. Rubber elbow
D. Induced draft blower