If the pilot fails to light, the main burner fails to light,
or the blower fails to come on, shut down gas heating
section and call your dealer for service. Failure to fol-
low these requirements could result in serious personal
injury.
TO SHUT UNIT OFF
Do not turn off the electrical power to unit without first
turning off the gas supply.
Failure to follow these procedures can result in seri-
ous fire or personal injury.
See Fig. 1 for location of gas valve. Refer to Fig. 3 while
proceeding with the following steps.
Step 1 —
Set room thermostat to lowest temperature set-
ting and set SYSTEM switch to OFF position.
Step 2 —
Close the external manual gas valve.
Step 3 —
Turn off the electrical power supply to the unit.
Step 4 —
Remove the burner compartment access panel.
Step 5 —
Turn the control dial on the internal gas valve
counterclockwise
to the OFF position.
Step 6 —
Replace the burner compartment access panel.
Step 7 —
If unit is being shut down because of a mal-
function, call your dealer as soon as possible.
If unit is being shut down because the heating season has
ended, restore electrical power to the unit to ensure opera-
tion of the cooling system during the cooling season.
Should overheating occur, or the gas supply fail to shut
off, shut off the manual gas valve to the unit before shutting
off the electrical supply.
Do not use this unit if any part has been under water. Im-
mediately call a qualified service technician to inspect the
unit and to replace any part of the control system and any
gas control which has been under water.
MAINTAINING YOUR UNIT
All maintenance should be handled by skilled, experi-
enced personnel. Your dealer can help you establish a stand-
ard procedure.
For your safety, keep the area around the unit clear and
free of combustible materials, gasoline, and other flam-
mable liquids and vapors.
To assure proper functioning of the unit, flow of combus-
tion and ventilating air must not be obstructed from reaching
the unit. Clearance of at least 4 ft on all sides is required.
ROUTINE MAINTENANCE AND CARE
FOR THE EQUIPMENT OWNER
Before proceeding with those things you might want to
maintain yourself, please carefully consider the following:
1. TURN OFF GAS SUPPLY AND ELECTRICAL
POWER TO YOUR UNIT BEFORE SERVICING
OR PERFORMING MAINTENANCE.
2. Do not turn off electrical power to this unit without
first turning off the gas supply.
3. When removing access doors or performing main-
tenance functions inside your unit, be aware of sharp
sheet metal parts and screws. Although special care
has been taken to reduce sharp edges to a minimum,
be extremely careful when handling parts or reach-
ing into the unit.
Air Filters —
Air filters should be checked at least every
3 or 4 weeks and changed or cleaned whenever they become
dirty. Table 1 indicates the correct filter size for your unit.
Remove the filter access panel to replace or inspect the fil-
ters. All units have filter tracks into which the filters slide.
Remove the filters by pulling outward from the track. See
Fig. 4 for filter access panel location. Note the direction of
flow arrows on the filter frame.
For horizontal supply/return units, the size, location and
number of air filters varies from Table 1. If you have diffi-
culty in locating your air filter in the return-air duct system,
or if you have questions concerning proper filter mainte-
nance, contact your dealer for instructions. When replacing
your unit filters, always use the same size and type of filter
that was originally supplied by the installer.
Units with outdoor air capability have a cleanable filter
for the outdoor air. This filter should be checked annually
and cleaned as necessary. Remove by removing screws in
outdoor air filter retainer and sliding filters out of the unit.
Never operate your unit without filters in place. Failure
to heed this warning may result in damage to the blower
motor and/or compressor. An accumulation of dust and
lint on internal parts of your unit can cause loss of ef-
ficiency and in some cases, fire.
Table 1 — Indoor-Air Filter Data*
UNIT
48
TYPE OF
FILTER
QUANTITY...SIZE (in.)
HJ
Fiberglass
Throwaway
4...20 x 20 x 2
4...16 x 20 x 2
TJ†
Fiberglass
Throwaway
4...20 x 20 x 2
4...16 x 20 x 2
*When replacing filters, always use the same type and size originally
supplied.
†The 48TJ028 unit requires 2-in. industrial grade filters capable of
handling face velocities of up to 625 ft/min (such as American Air
Filter no. 5700 or equivalent).
INTEGRATED GAS
UNIT CONTROLLER
(HIDDEN)
INDUCED DRAFT
MOTOR
FLUE BOX
COVER
MAIN BURNER
SECTION
MAIN GAS
VALVE
COMBUSTION
FAN HOUSING
Fig. 1 — Typical Gas Heating Section
2
