Carrier 48HG024 Guide

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111 Catalog No. 534-80029 Printed in U.S.A. Form 48HG-2SO Pg 1 3-01 Replaces: 48HG-1SO
Book 1 4
Ta b 1 a 6 a
User’s Information Manual
NOTE TO INSTALLER:
This manual should be left with the equipment owner.
Your combination heating/cooling unit is equipped with di-
rect spark ignition and induced draft power combustion blower.
TO LIGHT UNIT
See Fig. 1 for location of gas valve. Refer to Fig. 2 while
proceeding with the following steps.
Step 1 — Set room thermostat to the lowest temperature
setting and set SYSTEM switch to OFF position.
Step 2 — Close the external manual gas valve.
Step 3 — Turn off the electrical supply to the unit and
install lockout tag.
Step 4 — Remove the heat section access panel.
Step 5 — Turn the control dial on the internal gas valve
counterclockwise to the OFF position and wait 5 minutes.
Step 6 — Turn control dial on internal gas valve clockwise
to ON position.
Step 7 — Replace the heat section access panel.
Step 8 — Remove lockout tag and turn on the electrical
supply to unit.
Step 9 — Open the external gas valve.
Step 10 — Set room thermostat selector slightly above
room temperature and set system switch to HEAT position to
start the unit. The induced-draft combustion air fan will start.
Main burners light within 30 seconds. Indoor blower will start
within a few seconds of main gas ignition.
Step 11 — Set the temperature selector on room thermostat
to desired setting.
WARNING: If the information in this man-
ual is not followed exactly, a fire or explo-
sion may result causing property
damage, personal injury or loss of life.
— Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch;
do not use any phone in your
building.
• Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas sup-
plier, call the fire department.
— Installation and service must be per-
formed by a qualified installer, service
agency or the gas supplier.
Improper installation, adjustment, alteration, ser-
vice or maintenance can cause injury or property
damage. Refer to this manual. For assistance or
additional information consult a qualified installer,
service agency, or the gas supplier.
Before performing recommended maintenance, be sure
main power switch to unit is turned off and lockout tag is
installed. Electrical shock could cause personal injury.
Burners will light automatically. Do not attempt to light by
hand; personal injury may result.
1. Do not turn off the electrical power to unit without
first turning off the gas supply.
2. Before attempting to start the gas heating section,
familiarize yourself with all the procedures that must
be followed.
3. Never attempt to manually light the burners on the
unit with a match, lighter, or any other flame. If the
electric sparking device fails to light the burners, refer
to the shutdown procedures, then call your dealer as
soon as possible.
If you do not follow these instructions exactly, a fire or
explosion may result, causing property damage, injury, or
loss of life.
48HG014-028
Gas Heating/
Electric Cooling Units

2
TO SHUT UNIT OFF
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 setting
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
and install lockout tag.
Step 4 — Remove the heat section access panel.
Step 5 — Turn the control dial on the internal gas valve
counterclockwise to the OFF position.
Step 6 — Replace the heat section access panel.
Step 7 — If unit is being shut down because of a malfunc-
tion, 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 operation
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. Imme-
diately 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, experienced
personnel. Your dealer can help you establish a standard
procedure.
For your safety, keep the area around the unit clear and free
of combustible materials, gasoline and other flammable liquids
and vapors.
To assure proper functioning of the unit, flow of combustion
and ventilating air must not be obstructed from reaching the
unit. Clearance of at least 6 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:
Air Filter(s) — 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. Open the filter access panel to replace or inspect the
filters. All units have filter tracks into which the filters slide.
Remove the filters by pulling the filter slide outward from the
track. See Fig. 4 for filter access panel location. Note the direc-
tion of flow arrows on the filter frame.
If you have difficulty in locating your air filter in the return-
air duct system, or if you have questions concerning proper fil-
ter maintenance, contact your dealer for instructions. When re-
placing 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 cleanable filters for
the outdoor air. These filters should be checked annually and
cleaned as necessary. Remove by pulling out the middle of the
hood top. Push up on the center filter and then remove. Slide
the other filters to the center and repeat.
.
Table 1 — Indoor Air Filter Data*
*When replacing filters, always use the same type and size originally
supplied.
If the main burners fail to light, or the blower fails to come
on, shut down gas heating section and call your dealer for
service. Failure to follow these requirements could result in
serious personal injury.
Do not turn off the electrical power to unit without first
turning off the gas supply.
Failure to follow these procedures can result in serious
fire or personal injury.
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 mainte-
nance 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 reaching
into 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 efficiency
and in some cases, fire.
UNIT
48HG TYPE OF FILTER QUANTITY...SIZE
(in.)
014-
024
Standard Throwaway, Optional 30%,
or Accessory 65% Pleated 9...16 x 25 x 2
028 Standard Throwaway, Optional 30%,
or Accessory 65% Pleated 9...18 x 24 x 2
HEAT
EXCHANGER
SECTION
IGC BOARD
(HIDDEN)
COMBUSTION
FAN HOUSING
MAIN BURNER
SECTION
INDUCED
DRAFT
MOTOR
MAIN GAS
VALVE
LEGEND
Fig. 1 — Typical Gas Heating Section
IGC — Integrated Gas Controller

3
LOCK-OUT
TAG
ON
OFF
MAIN
STEP 1
Fig. 2 — To Light Unit
STEP 5STEP 4
STEP 3
STEP 2
STEP 8
STEP 7
STEP 6
STEP 10
STEP 9

4
STEP 1
Fig. 3 — To Shut Unit Off
STEP 7
STEP 6
STEP 5
STEP 4
STEP 3STEP 2
LOCK-OUT
TAG
ON
OFF
MAIN
STEP 3

5
Heat Exchanger — To ensure dependable and efficient
heating operation, the heat exchanger should be checked by a
qualified maintenance person before each heating season, and
cleaned when necessary. This checkout should not be attempt-
ed by anyone not having the required expertise and equipment
to do the job properly. Checking and/or cleaning the heat ex-
changer involves removing the gas controls assembly and the
flue collector box cover and, when completed, reinstalling the
gas controls assembly for proper operation. Also, the flue col-
lector box cover must be replaced correctly so that a proper
seal is maintained. Contact your dealer for the required period-
ic maintenance.
Fans and Belts — Periodically check the condition of
fan wheels and housings, and belt tension. When service is nec-
essary, call your dealer.
Evaporator-, Condenser-, and Combustion
Fan Motors — Lubrication is not recommended. Bearings
will not require lubrication for at least 5 years of normal opera-
tion. After 5 years, motor life can be extended by having the
motors serviced at an authorized motor service shop.
Fan Shaft Bearings — Lubrication should only be done
by qualified service personnel. Contact your dealer for the re-
quired annual maintenance.
Evaporator and Condenser Coils — Cleaning of the
coils should only be done by qualified service personnel. Con-
tact your dealer for the required annual maintenance.
Condensate Drain — The drain pan and condensate
drain line should be checked and cleaned at the same time the
cooling coils are checked by your dealer.
Compressors — All compressors are factory shipped
with a normal charge of the correct type refrigerant grade oil in
them and should rarely require additional oil. The service tech-
nician must be certain the proper oil level is maintained in the
compressor when it is installed and running.
PULL OUT CENTER OF
HOOD TO RELEASE OUTDOOR AIR
FILTER FROM TRACK
CONTROL BOX
ACCESS DOOR
INDOOR MOTOR
ACCESS DOOR
GAS VALVE
CONNECTION
FILTER
ACCESS
DOOR
HEAT
SECTION
ACCESS
PANEL
Fig. 4 — Panel and Filter Locations

6
Condenser Fan
The fan must be kept free of all obstructions to ensure prop-
er cooling. Contact your dealer for any required service.
Electrical Controls and Wiring — Electrical controls
are difficult to check without proper instrumentation; therefore,
if there are any discrepancies in the operating cycle, contact
your dealer and request service.
Integrated Gas Controller (IGC) — The IGC board
incorporates an LED that emits a flashing light to indicate an
alarm code. If the furnace section will not operate and the LED
is flashing a code (1 to 9 flashes in succession), contact your
dealer and request service. See Fig. 1.
Refrigerant Circuits — The refrigerant circuits are dif-
ficult to check for leaks without the proper equipment; there-
fore, if inadequate cooling is suspected, contact your dealer for
service.
Combustion Area and Vent System — The com-
bustion area and vent system should be visually inspected be-
fore each heating season. The normal accumulation of dirt,
soot, rust, and scale can result in loss of efficiency and improp-
er performance if allowed to build up.
See Fig. 1 and proceed as follows to inspect the combustion
area and power-venting system of your unit.
1. Turn off electrical power (install disconnect tag) and gas
supply to your unit.
2. Remove burner compartment access panel.
3. Using a flashlight, carefully inspect the burner areas for
dirt, soot, or scale.
4. When you have completed your inspection, follow the
start-up procedures in this manual to restore your unit to
operation.
5. Observe unit heating operation, and watch the burner
flame with the access panel removed to see if it is bright
blue. If you observe a suspected malfunction, or that the
burner flames are not bright blue, call your dealer. See
Fig. 5. Some yellow flame may be present due to the pan-
el being removed.
6. Replace burner compartment access panel.
Unit Panels — After performing any maintenance or
service on the unit, be sure all panels are securely fastened in
place to prevent rain from entering unit cabinet and to prevent
disruption of the correct unit airflow pattern.
Do not poke sticks, screwdrivers, or any other object into
revolving fan blades. Severe bodily injury may result.
If your unit makes an especially loud noise when the main
burners are ignited, shut down the heating section and call
your dealer.
If dirt, soot, rust or scale accumulations are found, call your
dealer and do not operate your heating section.
Fig. 5 — Proper Flame Appearance

7
REGULAR DEALER MAINTENANCE
In addition to the type of routine maintenance you might be
willing to perform, your unit should be inspected regularly by a
properly trained service technician. An inspection (preferably
each year, but at least every other year) should include the
following:
1. Inspection of all flue product passages — including the
burners, combustion baffles, heat exchanger, flue collec-
tor box, and vent pipe.
2. Inspection of all combustion- and ventilation-air passages
and openings.
3. Close inspection of all gas pipes leading to and inside
your unit.
4. Inspection, and if required, cleaning of the condenser and
evaporator coils.
5. Inspection, and if required, cleaning of the evaporator
drain pan.
6. Inspection, cleaning, and lubrication of blower wheel
housing and motor.
7. Inspection of all supply- and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems
found should be resolved at this time.
8. Inspection of the unit base to ensure that no cracks, gaps,
etc., exist which may cause a hazardous condition.
9. Inspection of the unit casing for signs of deterioration.
10. Inspection of all electrical wiring and components to
assure proper connection.
11. Inspection for leaks in the refrigerant circuit. Pressure-
check to determine appropriate refrigerant charge
12. Operational check of the unit to determine working con-
ditions. Repair or adjustment should be made at this time.
13. Your servicing dealer may offer an economical service
contract that covers seasonal inspections. Ask for further
details.
Complete Service Instructions can be found in the unit
Installation, Start-Up and Service Instructions.
BEFORE YOU CALL FOR SERVICE CHECK
FOR SEVERAL EASILY SOLVED PROBLEMS
If insufficient heating or cooling is suspected:
( ) Check for sufficient airflow. Check the air filter for dirt.
Check for blocked return- or supply-air grilles. Be sure they
are open and unobstructed. If these checks do not reveal the
cause, call your servicing dealer.
If your unit is not operating at all, check the following list
for easy solutions:
( ) Check to be sure that your thermostat temperature selec-
tor is set above the indoor temperature during the heating sea-
son, or below the indoor temperature during the cooling
season. Be sure the SYSTEM switch in the proper HEAT or
COOL position and not in the OFF position.
( ) Is the electrical supply switch on? Are any fuses blown,
or has the circuit breaker tripped?
( ) During the heating season, check the manual gas shutoff
valve. Is this lever parallel with the pipe, indicating that the
valve is open? Or is the lever at the right angle, indicating that
the valve is closed? If closed, has the gas been shut off for
safety reasons? Otherwise, you may open the valve and follow
the start-up procedures listed in this manual.
NOTE: Before proceeding with the next check, turn off the
electrical power supply to the unit. Remove the control access
door.
( ) During the heating season, check the control dial on the
gas valve. Is it in the ON position? If it is not, be sure it has not
been turned off for the purpose of safety. If nothing else is
incorrect, follow the start-up procedures in this manual.
( ) If your unit still fails to operate, call your servicing dealer
for troubleshooting and repairs. Specify the model and serial
numbers of your unit. (Record them in this manual in the space
provided.) If the dealer knows exactly which unit you have, he
may be able to offer suggestions over the phone, or save valu-
able time through knowledgeable preparation for the service
call.
IN CASE OF TROUBLE
If, after performing the above, unit performance is unsatis-
factory, shut off the unit and call your dealer.
Dealer’s Name _____________________________________
Telephone No.______________________________________
Unit Model ________________________________________
Unit Serial Number _________________________________

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111 Catalog No. 534-80029 Printed in U.S.A. Form 48HG-2SO Pg 8 3-01 Replaces: 48HG-1SO
Book 1 4
Ta b 1 a 6 a
Copyright 2001 Carrier Corporation