6
FILTERING OUT
TROUBLE
A dirty filter will cause excessive stress
on the furnace blower motor and can
cause it to overheat and automatically
shut down. The furnace filter should be
checked every 4 weeks or so and
cleaned or replaced if necessary.
If installed with factory specified dis-
posable media filter, check or replace
filter before each heating and cooling
season. Replace disposable media filter
at least twice a year.
If your furnace filter needs replacing, be
sure to use the same size and type of fil-
ter that was originally specified.
The air filter may be located in the filter
cabinet attached to the side or bottom
of the furnace.
If air filter has been installed in another
location, contact your dealer for instruc-
tions. To inspect, clean, and/or replace
the air filter(s), follow these steps:
1. Turn off electrical supply to fur-
nace (See Fig. 7.)
2. Remove filter cabinet door (See
Fig. 18 and 19.)
NOTE:
It may be necessary to re-
move 1 thumbscrew
3. Slide air filter out of filter cabinet.
Keep dirty side up (if dirty) to avoid
spilling dirt. (See Fig. 20 and 21.)
4. Inspect the filter. If torn, replace it.
NOTE:
If a washable filter has been re-
placed by:
a) Factory specified disposable media
filter – Do not clean. If dirty, replace only
with media filter having the same part
number and size. Install with airflow di-
rection arrow pointing towards blower.
b) Electronic air cleaner (EAC) – Re-
fer to EAC Owner’s Manual for mainte-
nance information.
5. Wash filter (if dirty) in sink, bath-
tub, or outside with a garden hose.
Always use cold tap water. A mild
liquid detergent may be used if nec-
essary. Spray water through filter in
the opposite direction of airflow.
CAUTION
Never operate your furnace
without a filter in place. Doing
so may damage the furnace
blower motor. An accumula-
tion of dust and lint on internal
parts of your furnace can
cause a loss of efficiency.
!
Allow filter to dry.
6. Reinstall clean air filter.
7. Replace filter cabinet door. (See
Fig. 22 and 23.)
8. Turn on electrical supply to furnace
(See Fig. 12.)
* Recommended ** Some furnaces may have 2 filters
Filters may be field modified by cutting filter material
and support rods (3) in filters. Alternate sizes and addi-
tional filters may be ordered from your dealer.
COMBUSTION AREA
AND VENT SYSTEM
Inspect the combustion area and vent
system before each heating season. An
accumulation of dirt, soot, or rust can
mean a loss of efficiency and improper
performance. Buildups on the main
burners can cause faulty firing. This
“delayed ignition’’ is characterized by
an alarmingly loud sound. If your fur-
nace makes a loud noise when the main
burners are ignited, shut down the fur-
nace—call your servicing dealer.
Use your flashlight and follow these
steps for inspecting the combustion
area and vent system of your furnace:
1. Turn off the electrical supply to the
furnace and remove the access
door. (See Fig. 7 and 8.)
2. Carefully inspect the gas burner
(See Fig. 17) for dirt, rust, or scale.
Then inspect the elbow, flue con-
nection area, and the vent pipe for
rust.
17
NOTE:
If dirt, rust, soot, or scale accu-
mulations are found, call your servic-
ing dealer. DO NOT OPERATE THE
FURNACE.
3. Inspect the vent pipe for a sag,
holes, or a disconnection. A hori-
zontal vent pipe must slope upward
away from furnace. If rusty joints
or seams, or signs of water leakages
are found, call your dealer for
service.
4. Restore electrical power to the fur-
nace. (See Fig. 12.)
5. Start the furnace and observe its
operation. If possible, watch the
burner flames. Are they burning
bright blue? If not (or if you suspect
some other malfunction), call your
servicing dealer.
6. Replace access door. (See Fig. 11.)
18
FURNACE
CASING
WIDTH
FILTER QUANTITY
AND SIZE
**
FILTER
TYPE
*
SIDE
RETURN
BOTTOM
RETURN
14-1/2
(1) 16 x 25
(1) 14 x 25
1” thick,
cleanable or
4-5/16” thick
media-type
17-1/2
(1) 16 x 25
(1) 16 x 25
1” thick,
cleanable or
4-5/16” thick
media-type
21
(1) 16 x 25
(1) 20 x 25
1” thick,
cleanable or
4-5/16” thick
media-type
24
(1) 16 x 25
(1) 24 x 25
1” thick,
cleanable or
4-5/16” thick
media-type
CAUTION
Use care when cutting support
rods in filters to protect
against flying pieces and
sharp rod ends. Wear safety
glasses, gloves, and appropri-
ate protective clothing. Failure
to follow this caution could re-
sult in personal injury.
!
WARNING
If holes are found—or if the
vent pipe is obstructed or is
not connected—toxic fumes
can escape into your home. DO
NOT OPERATE YOUR FUR-
NACE. Call your dealer for ser-
vice. A failure to follow this
warning could result in per-
sonal injury or death.
!
