Installation Manual

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Specifications subject to change without notice.
17. Slope the vent and combustion air piping downward
towards furnace. A minimum slope of at least 1/4-in. (6
mm) per linear ft.(1-in (25 mm) per 4 ft.(1.2 M)) with no
sags between hangers is required. See Caution Box below.
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in nuisance short
cycling, frozen vent termination, and/or no heat.
Slope the vent and combustion air piping downward towards
furnace a minimum of 1/4 --in. (6 mm) per linear ft. of pipe.
CAUTION
!
18. Complete the vent and combustion air pipe installation by
connecting the concentric vent or by installing the required
termination elbows as shown in Figs. 40, 39 and 56.
For Ventilated Combustion Air Termination, See Fig. 57.
19. Use appropriate methods to seal openings where combus-
tion air pipe and vent pipe pass through roof or sidewall.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
DO NOT use cement to join polypropylene venting systems.
Follow the polypropylene venting system manufacturer ’s
instructions for installing polypropylene venting systems.
!
WARNING
Attach gaskets to vent pipe and
combustion air adapters.
Vent Coupling and Adapter
A13074
Fig. 44 -- Vent Coupling and Adapter with Gaskets
Table 13 – Hanger Spacing
Diameter
Material
PVC Sch 40 SDR 21 & 26 ABS CPVC Polypropylene
11/2--in. 3--ft. 2 1/2--ft. 3--ft. 3--ft. 3.25--ft.
38--mm 914--mm 762--mm 914--mm 914--mm 1000 mm
2--in. 3--ft. 3--ft. 3--ft. 3--ft. 3.25--ft.
51--mm 914--mm 914--mm 914--mm 914--mm 1000 mm
21/2--in. 3 1/2--ft. 3--ft. 3 1/2--ft. 3 1/2--ft. 3.25--ft.
64--mm 1067--mm 914--mm 1067--mm 1067--mm 1000 mm
3--in. 3 1/2--ft. 3--ft. 3 1/2--ft. 3 1/2--ft. 3.25--ft.
76--mm 1067--mm 914--mm 1067--mm 1067--mm 1000 mm
4--in. 4--ft. 3 1/2--ft. 4--ft. 4--ft. 3.25--ft.
Optional Installation of the Vent Pipe
NOTE: DO NOT USE THIS TECHNIQUE FOR
POLYPROPYLENE VENTING SYSTEMS.
This option provides a disconnect point for the vent pipe. The vent
pipe must be cemented to the plastic vent pipe adapter to maintain
a sealed vestibule. See Fig. 52.
1. Insert a length of vent pipe through the casing into the
outlet of the vent elbow.
2. Slide the plastic vent pipe adapter over the length of the
vent pipe down to the furnace casing. Mark the pipe where
it is flush with the outlet of the adapter.
3. Remove the pipe from the furnace and the adapter and cut
off any excess pipe.
4. Clean and prime the end of the pipe that is flush with the
vent adapter with a primer that is appropriate for the type of
pipe being used.
5. Re--insert the pipe through the casing into the vent elbow.
6. Tighten the clamp around the outlet of the vent elbow.
Torque the clamp to 15 lb--in.
7. Apply cement to the end of the pipe and to the inside of the
plastic vent adapter.
8. Slide the adapter over the vent pipe and align the screw
holes in the adapter with the dimples in the furnace casing.
9. Pilot drill 1/8-- in. screw holes for the adapter in the casing
and secure the adapter to the furnace with sheet metal
screws.
10. Loosen the clamps on the rubber vent coupling.