Carrier 48ZT - Manual (Page 8)

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480045-01 Printed in U.S.A. Form 48Z-5SO Pg 8 7-07 Replaces: 48Z-3SO Book 1
Tab 1a
Copyright 2007 Carrier Corporation
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, heat exchanger, flue collector box, and vent pipe.
2. Inspection of all combustion-air and ventilation-air pas-
sages and openings.
3. Close inspection of all gas pipes leading to and inside
your unit.
4. Adjustment of the air/gas mixture if the burner flames are
not bright blue. (See Fig. 5 and 6 for location of access
panel and proper flame appearance.)
5. Inspection, and if required, cleaning of the condenser and
evaporator coils.
6. Inspection, and if required, cleaning of the evaporator
drain pan.
7. Inspection, cleaning, and lubrication of blower wheel
housing and motor.
8. Inspection of all supply-air and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems
found should be resolved at this time.
9. Inspection of the unit base to ensure that no cracks, gaps,
etc., exist which may cause a hazardous condition.
10. Inspection of the unit casing for signs of deterioration.
11. Inspection of all electrical wiring and components to
assure proper connection.
12. Inspection for leaks in the refrigerant circuit. Pressure-
check to determine appropriate refrigerant charge.
13. Operational check of the unit to determine working con-
ditions. Repair or adjustment should be made at this time.
14. 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 base unit
Controls, Start-Up, Operation, Service and Troubleshooting
literature.
BEFORE YOU CALL FOR SERVICE, CHECK
FOR SEVERAL EASILY SOLVED PROBLEMS
If insufficient heat or cooling is suspected:
( ) Check for sufficient airflow. Check the air filters for dirt.
Check for blocked return-air or supply-air grilles. Be sure they
are open and unobstructed. Be sure heating and cooling set
points are correct. 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 heating temperature set point is set
above the indoor temperature during the heating season, or that
cooling temperature set point is below the indoor temperature
during the cooling season. Be sure the unit on/off switch is in
the ON position and not in the OFF position. Be sure unit has
been programmed with the appropriate time schedules and
desired operating set points.
( ) Is the electrical supply switch ON? Are any fuses blown,
or have any of the circuit breakers tripped?
( ) During the heating season, check the manual shutoff
valve. Is this lever parallel with the pipe, indicating that the
valve is open? Or is the lever at a 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. Open the control access
door.
( ) During the heating season, check the control switch on
the gas valve. It is in the ON position? If it is not, be sure it has
not been turned off for the purpose of safety. 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 _________________________________
Unit Address ______________________________________
Bus Number _______________________________________