![background image](http://html.mh-extra.com/html/carrier/gas-furnace-58mta/gas-furnace-58mta_installation-start-up-and-operating-instructions-manual_2562952019.webp)
CUTS AND ABRASION HAZARD
Failure to follow this caution may result in minor personal
injury.
Use care when cutting support rods in filters to protect against
flying pieces and sharp rod ends. Wear safety glasses, gloves,
and appropriate protective clothing.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
For airflow requirements above 1800 CFM, see Air Delivery
table in Product Data literature for specific use of single side
inlets. The use of both side inlets, a combination of 1 side and
the bottom, or the bottom only will ensure adequate return air
openings for airflow requirements above 1800 CFM.
NOTE:
Side return-air openings can ONLY be used in UPFLOW
configurations. Install filter(s) as shown in Fig. 23. Bottom
return-air opening may be used with all 4 orientations. Filter may
need to be cut to fit some furnace widths. Install filter as shown in
Fig. 24.
NOTE:
Remove and discard bottom closure panel when bottom
inlet is used.
Step 6—Bottom Closure Panel
This furnace is shipped with bottom closure panel installed in
bottom return-air opening. This panel MUST be in place when side
return air is used.
To remove bottom closure panel, perform the following:
1. Tilt or raise furnace and remove 2 screws holding front filler
panel. (See Fig. 25.)
2. Rotate front filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
Table 2—FILTER INFORMATION
AIR FILTER LOCATED IN BLOWER COMPARTMENT
FURNACE
CASING
WIDTH (IN.)
FILTER SIZE (IN.)*
FILTER
TYPE
Side Return
Bottom Return
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 dealer.
† Factory-provided with furnace.
Fig. 23—Filter Installed for Side Inlet
A93045
FILTER
RETAINER
WASHABLE
FILTER
Fig. 24—Bottom Filter Arrangement
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
″
Fig. 25—Removing Bottom Closure Panel
A93047
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
19