7
7. Replace main furnace door. See Fig. 12.
A05088
Fig. 12 -- Furnace Door Replaced
8. Turn ON the electrical supply to the furnace and wait 1 minute.
See Fig. 13.
A92359
Fig. 13 -- Turn on Electrical Supply
9. Open the external manual gas valve. See Fig. 14.
OP
EN
A06189
Fig. 14 -- Open Valve
10. Set the room thermostat to a temperature slightly above the
room temperature. This will automatically signal the furnace
to start.
11. When the furnace receives the start signal, the inducer is star-
ted. When the pressure switch senses that there is sufficient
combustion air, the hot surface igniter is energized.
After the hot surface igniter is heated for 17 seconds, the gas
valve permits gas to flow to the main burners. After ignition
and a time delay of about 60 sec, the furnace blower will start.
Variable--capacity furnaces start at low speed until the control
makes the necessary adjustments to operate the blower at
either the low-- or high--heat speed.
NOTE:
If the main burners fail to ignite after four attempts, the
furnace control system will lock out. If lockout occurs, main
burners fail to light, or blower does not come on, shut down the
furnace and call your dealer for service.
12. Set your thermostat to the temperature that satisfies your
comfort requirements. SUGGESTION: Setting the thermo-
stat back a few degrees—and compensating for the differ-
ence with warmer clothing—can make a big difference in
your fuel consumption on extremely cold days. The few de-
grees at the top of your thermostat “comfort level” are the
most costly degrees to obtain.
When the room temperature drops below the temperature selected
on the thermostat, the furnace will switch on automatically. When
the room temperature reaches the setting selected on the thermostat,
the furnace will be automatically switched off.
Continuous Fan Operation
--Some thermostats have a “FAN”
switch with 2 selections: AUTO and ON. When thermostat is set
on AUTO, the furnace blower cycles on and off, controlled by the
thermostat. In ON position, the furnace blower runs continuously.
Continuous fan keeps the temperature level in your home more
evenly balanced. It also continuously filters the indoor air.
Comfort Fan
t
-- On all but the base series furnace, the blower
speed can be increased or decreased if desired due to change of
seasons, large gatherings in your home, etc. Simply change your
FAN from ON to OFF for 1 to 3 seconds (or AUTO depending on
your thermostat), and then return to ON. The blower will switch to
the next higher speed. There are at least three speeds to choose
from. If the blower is running on its highest speed, a request to
change will direct the blower to return to its lowest speed.
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:
1. Set your room thermostat to the lowest temperature setting.
See Fig. 15.
A09564
Fig. 15 -- Lowest Temperature Setting
2. Close the external manual gas valve. See Fig. 16.
CLO
SE
A06188
Fig. 16 -- Close the External Manual Valve
