Performing Routine Maintenance; Filtering Out Trouble - Carrier 58DXT User's Information Manual

22
4. Remove the control access door on your furnace. (See
Fig. 10 or 11.) On upflow furnaces, removing the blower
access door is not required.
5. Turn the control knob or electric switch on the gas valve
to the OFF position. (See Fig. 22 or 23.)
6. Replace the control access door. (See Fig. 16 or 17.)
7. If the furnace is being shut down because of a malfunc-
tion, call your dealer as soon as possible.
PERFORMING ROUTINE
MAINTENANCE
With proper maintenance and care, your furnace will oper-
ate economically and dependably. Basic maintenance,
which can easily be accomplished by someone who follows
the directions, is found on this and the following pages.
However, before beginning maintenance, follow these safety
precautions:
WARNING
!
Turn off electrical power supply to your furnace
before removing the access doors to service or
perform maintenance. A failure to follow this
warning could result in personal injury or death.
CAUTION
!
Although special care has been taken to minimize
sharp edges, be extremely careful when handling
parts or reaching into the furnace.

FILTERING OUT TROUBLE

A dirty filter will cause excessive stress on the furnace, heat
exchanger, and blower motor and can cause it to overheat
and automatically shut down. The furnace filter should be
checked every 3 or 4 weeks and cleaned if necessary.
If your furnace filter needs replacing, be sure to use the
same size and type of filter that was originally supplied. Use
the Furnace Filter Table and match your furnace size with
the proper filter size.
CAUTION
!
Never operate your furnace without a filter in
place. Doing so may damage the furnace blower
motor. An accumulation of dust and lint on in-
ternal parts of your furnace can cause a loss of
efficiency.
The air filter for upflow furnaces is normally located in the
blower compartment. Filters for the downflow furnaces are
normally located in the return-air plenum above the blower.
If the filters have been installed in another location, contact
your dealer for instructions. To inspect, clean and/or
replace the air filter(s), follow these steps:
• Upflow/Horizontal Furnaces Only—
1. Turn off the electrical supply to the furnace. (See
Fig. 21.)
2. Remove control and blower access doors. (See Fig. 11.)
23
3. Push filter retainer toward the bracket opening to
release the filter. (See Fig. 24.)
4. Gently remove the filter and carefully turn the dirty
side up (if dirty) to avoid spilling dirt from the filter.
(See Fig. 25.)
5. Inspect the filter. If torn, replace the filter.
6. Wash the filter (if dirty) in a sink, bathtub, or outside
with a garden hose. Always use cold tap water. A mild
liquid detergent may be used if necessary. Spray water
through the filter in the opposite direction of airflow
through the cross-mesh binding (when present) side.
Allow filter to dry.
7. Reinstall the clean filter with the cross-mesh binding
(when present) side facing the furnace blower.
8. Put filter retainer back in the bracket opening and lock
it in place.
9. Replace blower and control access doors and turn on
electrical supply to the furnace. (See Fig. 26, 16, and 18.)
NOTE: Two filters may be required in some upflow models
if side return ducts are used. The procedure listed above
may be used to remove side filters.
• Downflow Furnaces Only:
Two filters are located in the return-air plenum above the
blower (above line-of-sight) resting in the V-shaped channel
on top of the furnace. (See Fig. 27.)
6
24 25
26