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.
WARNING:
Never operate unit without a filter or with
filter access door removed. Failure to follow this warning
can cause fire, personal injury, or death.
VI.
LEVELING LEGS (IF REQUIRED)
When 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 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.
Fig. 5—Side Filter Arrangement
(Control Removed for Clarity)
A93045
FILTER
RETAINER
WASHABLE
FILTER
→
Fig. 6—Bottom Filter Arrangement
(Control Removed for Clarity)
A00290
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
″
21-IN. WIDE
CASINGS ONLY:
SUPPORT RODS (3)
EXTEND 1/4" ON EACH
SIDE OF FILTER AND
REST ON CASING FLANGE
→
TABLE 3—FILTER INFORMATION (IN.)
FURNACE
CASING WIDTH
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 can be ordered from your distributor or dealer.
† Factory provided with the furnace.
Fig. 7—Leveling Leg Installation
A89014
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
—7—
