6
 
When room temperature drops below the temperature 
selected on the thermostat, the furnace will be 
switched on automatically. When room temperature 
reaches the degree selected on the thermostat, the  
furnace will be switched off automatically.
Some thermostats have a FAN switch with 2 selections, 
AUTO and ON. When thermostat is set to AUTO, the
furnace blower cycles on and off, controlled by the 
thermostat. In ON position, the furnace blower runs 
continuously. This keeps the temperature level in your 
home more evenly balanced. It also continuously filters 
the indoor air.
 
SHUTTING DOWN YOUR FURNACE
 
Should you need to shut down your furnace for service 
or maintenance, you will need to turn the furnace off. 
The following procedures must be followed:
 
16 17
 
1. Set your room thermostat to the lowest temperature 
setting. (See Fig. 16.)
2. Close the external manual gas valve. 
(See Fig. 9.)
3. Turn off electrical supply to the furnace. 
(See Fig. 17.)
4. Remove furnace access door.
 (See Fig. 11.)
5. Turn control knob on the gas valve to OFF position. 
(See Fig. 18.)
6. Replace furnace access door. (See Fig. 13.)
7. If the furnace is being shut down because of a 
malfunction, call your dealer as soon as possible. 
 
 
PERFORMING ROUTINE MAINTENANCE
 
With proper maintenance and care, your furnace will oper-
ate economically and dependably. Instructions for basic 
maintenance, which can easily be followed, are found on this 
and the following pages. However, before beginning mainte-
nance, follow these safety precautions:
 
CAUTION
 
Furnace is not to be installed, operated, and then
turned off and left turned off in an unoccupied
structure during winter. (See winterizing proce-
dures in maintenance section).
SYSTEM
COOL
OFF
HEAT
FAN
AUTO
ON
50
70
90
50
70
90
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18
 
FILTERING OUT TROUBLE
A dirty filter will cause a loss of airflow in your duct system. 
When excessive loss of airflow occurs, the furnace may 
cycle on the safety controls. If this condition is left unat-
tended, the furnace will eventually lockout. It is recom-
mended that the furnace filter be checked every 3 or 4 weeks 
and cleaned if necessary.
The air filter is normally located in the blower compartment. 
(See Fig. 3 or 4.) If filter has been installed in another loca-
tion, contact your dealer for instructions. To inspect, clean 
and/or replace the air filter(s), follow these steps:
1. Turn off electrical supply to the furnace. (See Fig. 17.)
2. Remove furnace access door. (See Fig. 19.)
3. Remove blower access panel. (See Fig. 20.)
NOTE: It will be necessary to remove 1 screw.
• FILTER(S) LOCATED IN BOTTOM:
 1. Slide filter retainer sideways until it is free of latch. (See 
Fig. 21 and 22.)
• FILTER LOCATED IN SIDE:
1. Remove filter retainer from latch. (See Fig. 23.)
2. Gently remove filter and carefully turn the dirty side up 
(if dirty) to avoid spilling dirt from the filter. 
(See Fig. 24.)
3. Inspect the filter. If torn, replace it.
 
WARNING
 
Turn off electrical power supply to your furnace
before removing the access door to service or per-
form maintenance. Failure to follow this warning
could result in personal injury or death.
 
CAUTION
 
Although special care has been taken to minimize
sharp edges, be extremely careful when handling
parts or reaching into the furnace.
 
CAUTION
 
Never operate your furnace without a filter in place.
Doing so may damage the furnace blower motor.
An accumulation of dust and lint on internal parts
of your furnace can cause a loss of efficiency.
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