Table of Contents
Advertisement
Place temperature measuring device in the
return and supply air stream as close to the
furnace as possible. The device on the supply
air side must be shielded from direct radiation
from the heat exchanger to avoid false readings.
Adjust all registers and duct dampers to the
desired position and run the furnace for fifteen
minutes before taking any temperature read-
ings. The temperature rise is the difference
between the supply and return air tempera-
tures.
Verifying Burner Operation
To verify operation of the burners, make sure
that the blower compartment door is in place and
that there is power to the furnace. Set the
thermostat above room temperature and ob-
serve the ignition sequence. The flame can be
observed through the small clear window on the
burner box. The flames should be blue, without
yellow tips. Flames should extend from each
burner without lifting, curling, or floating. After
verifying ignition, set the thermostat below room
120 VAC
Common
Leads
Connect
Electronic
Air Cleaner
and/or Humidifier
30
4
5
6
1
2
3
Optional
Connector
COM
24 V
9
6
3
8
5
2
7
4
1
Neutrals
6
3
Neutral
Lead of
5
2
4
1
Here.
Humidifier Tap
(.5A@ 120 VAC)
Figure 24. Blower Speed Tap Location
temperature and verify that the burner flame
extinguishes completely.
Verifying Operation of the Supply
Air Limit Switch
To verify operation of the supply air limit switch,
make sure that the blower door is in place and that
there is power to the furnace. Completely block
the return airflow to the furnace by installing a
close-off plate in place of or upstream of the
filter(s). Set the thermostat above room tempera-
ture and verify that the Sequence of Operation is
as described in these instructions. The supply air
limit switch should function to turn off the gas
valve within approximately five minutes. The
circulating air and combustion blowers should
continue to run when the supply air limit switch
opens. Remove the close-off plate immediately
after the supply air limit switch opens. If the
furnace operates for more than five minutes with
no return air, set the thermostat below room
temperature, shut off the power to the furnace,
and replace the supply air limit switch.
ADD-ON BOARD
1
2
3
3 Amp Fuse
Flame Signal
Light (Yellow)
Status
Light (Red)
Main Board
Unused Motor
Leads
Electronic Air Tap
(.5A@ 120 VAC)
These motor speed taps are
not used for two-stage models
Timing Switch
Advertisement
Table of Contents
