Use care when cutting support rods in filters to protect against
flying pieces and sharp rod ends. Wear safety glasses, gloves,
and appropiate protective clothing. Failure to follow this
caution could result in personsl injury.
For bottom air-return applications, filter may need to be folded to
fit some furnace casing widths. A bottom closure panel is factory
installed in the bottom of the furnace. When bottom return inlet is
desired, remove and discard the bottom closure panel. Two sets of
hardware are needed for furnaces in 24-1/2-in. wide casings using
2 filters for bottom return. All hardware is provided for filter
installation.
NOTE:
Furnaces with a 17-1/2-in. wide casing require an addi-
tional procedure when locating the filter for bottom return-air
application. Field fabricate a sheet metal filler strip 1 X 3 X 24-1/2
in. and install it along side of the filter as shown in Fig. 6. Drive
2 screws through the casing side and into the filler strip to secure
it in place. Filter should rest on the top of the filler strip when
installed.
Never operate unit without a filter or with filter access door
removed. Failure to follow this warning can cause fire,
personal injury, or death.
Step 6—Leveling Legs (If Required)
When the furnace is used with side inlet(s) and leveling legs are
required, refer to Fig. 7, and install field-supplied, corrosion-
resistant 5/16-in. machine bolts and nuts.
NOTE:
The maximum length of the bolt should not exceed 1-1/2
in.
1. Lay furnace on its back. Locate and drill 5/16-in. diameter
hole in each bottom corner of furnace as shown in Fig. 7.
2. Install nut on bolt and install bolt and nut in hole. (Install flat
washer if desired.)
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
4. Adjust outside nut to provide desired height, and tighten inside
nut to secure arrangement.
Step 7—Gas Piping
Gas piping must be installed in accordance with national and local
codes and all authorities having jurisdiction. In the U.S.A., Refer
to the current edition of the NFGC. Canadian installations must be
installed in accordance with NSCNGPIC.
Refer to Table 4 for the recommended gas pipe size. Risers must
be used to connect to the furnace and the meter.
Fig. 5—Side Filter Arrangement
(Control Removed for Clarity)
A93045
FILTER
RETAINER
WASHABLE
FILTER
→
Fig. 6—Bottom Filter Arrangement
(Control Removed for Clarity)
A00213
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
17
1
⁄
2
-IN. WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
1
″
24
1
/
2
″
3
″
→
Table 3—Filter Information (In.)
FURNACE
CASING WIDTH
AIR FILTER LOCATED IN BLOWER
COMPARTMENT
FILTER SIZE*
FILTER TYPE
Side Return
Bottom Return
14-3/16
(1) 16 X 25 X 1†
(1) 14 X 25 X 1
Cleanable
17-1/2
(1) 16 X 25 X 1†
(1) 16 X 25 X 1†
Cleanable
21
(1) 16 X 25 X 1
(1) 20 X 25 X 1†
Cleanable
24-1/2
(1 or 2) 16 X 25 X 1 (1) 24 X 25 X 1†
Cleanable
* Filters may be field modified by cutting filter material and support rods (3) in
filters. Alternate sizes and additional filters may be ordered from your
distributor or dealer.
† Factory-provided with the furnace.
7
