If your unit makes an especially loud noise when the main burners are ignited, shut down the heating section and call your dealer. Proceed as follows to inspect the combustion area and power- venting system of your unit. 1. Turn off electrical power and gas supply to your unit. 2. Remove burner access panel. (See Fig. 1.) 3. Using a flashlight, carefully inspect the burner areas for dirt, soot, rust, or scale. See Fig. 2. If dirt, soot, rust, or scale accumulations are found, call your dealer and do not operate your heating section. 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. Components in heat section may be hot after unit has been started up. When observing flame, be careful not to get close to or touch heating components or serious personal injury may result. Watch the burner flame to see if it is bright blue. If you observe a suspected malfunction or if the burner flames are not bright blue, call your dealer. 6. Replace burner access panel. Unit Panels — After performing any maintenance or service on the unit, be sure all panels are fastened securely in place to prevent rain from entering unit cabinet and to prevent disruption of the correct unit airflow pattern. 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, and flue collector box. 2. Inspection of all combustion-and ventilation-air passages and openings. 3. Close inspection of all gas pipes leading to and inside of 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 and cleaning of blower wheel housing and motor. 7. Inspection of all supply-air 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. Inspection of compressor oil level. 13. Operational check of the unit to determine working conditions. Repair or adjustment should be made at this time. 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. WARRANTIES Units 48SS and 48SX each have a separate warranty located at the back of this book. Be sure to read the warranty carefully to determine the coverage for your unit. 7 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-air 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 selector is set above the indoor temperature during the heating season, or below the indoor temperature during the cooling season. Be sure the system switch is 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 external 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 gas supply, then the electrical power supply to the unit. Remove the control access door. ( ) During the heating season, check the control switch on the internal gas valve. Is it in the ON position? If it is not, be sure it was not turned off for the purpose of safety. If no safety hazards exist, 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 sugges...