10
28
29
30
If your furnace air
fi
lter needs to be replaced, be sure to use a factory authorized
fi
lter of the same size that was originally supplied.
Use the furnace air
fi
lter table and compare your furnace size with the proper
fi
lter size.
FURNACE AIR FILTER TABLE
* Furnace with a side return-air inlet may have a different
fi
lter size. Measure the
fi
lter to obtain the correct size.
COMBUSTION AREA AND VENT SYSTEM
Visually inspect the combustion area and vent system before each heating season. Make sure that all PVC pipes leading into the
combustion area and vent are free from any cracks and sags.
Check the combustion-air intake adjacent to the furnace or outside your home for blockage. Also check the vent pipe on the outside
of your home for blockage.
When dirt, soot, scale, or rust is allowed to build up, your furnace can suffer a loss of ef
fi
ciency and perform improperly. Accumu-
lations on the main burners can result in
fi
ring out of normal sequence. This delayed ignition creates an alarmingly loud sound.
To inspect the combustion area and vent system, you will need a
fl
ashlight. Refer to Fig. 1, and proceed as follows:
1. Turn off gas and electrical supplies to the furnace and remove the main furnace door. (See Fig. 8 and 9.)
2. Remove burner enclosure front. (See Fig. 31 or 32.)
Inspect the gas burners, igniter area, and remainder of furnace for dirt, soot, rust, or scale.
FURNACE CASING WIDTH (IN.)
FILTER SIZE* (IN.)
FILTER TYPE
17-1/2
(1) 16 x 25 x 1
Cleanable
21
(1) 20 x 25 x 1
Cleanable
24-1/2
(1) 24 x 25 x 1
Cleanable
WARNING:
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal injury.
Use care when cutting support rods in filters to protect against flying pieces and sharp rod ends. Wear safety
glasses, gloves, and appropriate protective clothing.
WARNING:
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury or death.
If holes are found in the pipes or if any portion has become disconnected, toxic fumes can escape into your home.
DO NOT OPERATE YOUR FURNACE. Call your dealer for service.
CAUTION:
UNIT OPERATION HAZARD
Failure to follow this caution may result in minor property damage.
If your furnace makes an especially loud noise when the main burners light, shut down your furnace and call
your dealer.
WARNING:
Failure to follow this warning could result in personal injury or death.
If dirt, rust, soot, or scale accumulations are found, call your dealer. Do not operate your furnace.
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