7operations must be performed by trained service person-nel. Observe safety precautions in this manual, on tags, andon labels attached to the furnace, and other safety precautionsthat may apply.With proper maintenance and care, your furnace will operateeconomically and dependably. Installations for basic mainte-nance are found on this and the following pages. However,before beginning maintenance, follow these safety precautions:FILTERING OUT TROUBLEA dirty air filter will cause a loss of airflow in your ductsystem. When excessive loss of airflow occurs, the furnacemay cycle on its safety controls. If this condition is left unat-tended, the furnace will eventually lock out. It is recom-mended that the furnace air filter be checked every 3 or 4weeks and cleaned if necessaryThe air filter is normally located in the blower compartment.(See Fig. 2) If air filter has been installed in another location,contact your dealer for instructions. To inspect, clean and/orreplace the air filter(s), follow these steps:1. Turn off the electrical supply to the furnace. (See Fig. 16.)2. Remove main furnace door. (See Fig. 18.)3. Remove blower access panel. (See Fig. 19.)NOTE: It will be necessary to remove 2 screws.4. Remove air filter from furnace.•AIR FILTER(S) LOCATED IN END OF FURNACE:a. Slide filter retainer sideways until it is free of latch. (SeeFig. 20.)b. Slide air filter out of furnace. (See Fig. 21.)18 1920 21• AIR FILTER LOCATED IN SIDE:a. Remove filter retainer from latch. (See Fig. 25.)b. Gently remove air filter and carefully turn the dirty side up (ifdirty) to avoid spilling dirt from the filter. (See Fig. 26.)5. Inspect the filter. If torn, replace it.22 23WARNINGTurn off electrical power supply to your furnacebefore removing the main furnace door to serviceor perform maintenance. Failure to follow thiswarning could result in personal injury or death.CAUTIONAlthough special care has been taken to minimizesharp edges, be extremely careful when handlingparts or reaching into the furnace.CAUTIONNever operate your furnace without a filter in place.Doing so may damage the furnace blower motor.An accumulation of dust and lint on internal partsof your furnace can cause a loss of efficiency.!!!