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11. Spin the blower wheel by hand to verify that the wheel
does not rub on the housing.
12. Reinstall blower assembly in furnace.
13. Reinstall two screws securing blower assembly to blower
deck.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in shortened heat
exchanger life.
Heating fan speed(s) MUST be adjusted to provide proper
air temperature rise as specified on the rating plate.
Recommended operation is at the midpoint of the rise range
or slightly above. Refer to "SET TEMPERATURE RISE"
under
START- -UP,
ADJUSTMENT,
CHECK.
NOTE: Refer to Table 5 for motor speed lead relocation if leads
were not identified before disconnection.
14. Refer to furnace wiring diagram, and connect thermostat
leads if previously disconnected.
15. To check blower for proper rotation:
a. Turn on electrical supply.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, or death.
Blower access door switch opens 115- -v power to
furnace control. No component operation can occur
unless switch is closed. Exercise caution to avoid
electrical shock from exposed electrical components
when manually closing this switch for service purposes.
b. Manually close blower access door switch.
c. Verify blower is rotating in the correct direction.
16. If furnace is operating properly, RELEASE BLOWER
ACCESS DOOR SWITCH. Remove any jumpers or
reconnect any disconnected thermostat leads. Replace
blower access door.
17. Reinstall outer door.
18. Cycle furnace through one complete heating and cooling
cycle. Verify the furnace temperature rise as shown in
"Adjustments" Section. Adjust temperature rise as shown
in "Adjustments" Section. If outdoor temperature is below
70_F, (21_C) turn off circuit breaker to outdoor unit be-
fore running furnace in the cooling cycle. Turn outdoor
circuit breaker on after completing cooling cycle.
FLAME SENSOR CLEANING AND SERVICING
IGNITOR
Cleaning Flame Sensor
The following items must be performed by a qualified service
technician. If the flame sensor develops an accumulation of light
dirt or dust, it may be cleaned by using the following procedure:
32
Refer to Fig. 36.
and
SAFETY
To reinstall ignitor and flame sensor:
NOTE: If insulation assembly is damaged, do not attempt to
repair, must be replaced with insulation kit.
NOTE: Proper use of Personal Protective Equipment (PPE)
must be followed, including safety glasses, gloves, and dust mask
when removing and reinstalling the heat exchanger insulation
assembly.
Specifications are subject to change without notice.
WARNING
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Turn off the gas and electrical supplies to the furnace and
install lockout tag before performing any maintenance or
service. Follow the operating instructions on the label
attached to the furnace.
1. Disconnect power at external disconnect, fuse or circuit
breaker.
2. Turn off gas at external shut-off or gas meter.
3. Remove control door and set aside.
4. Turn electric switch on gas valve to OFF.
5. Disconnect Flame Sensor wire from Flame Sensor.
6. Remove the flame sensor from the burner assembly.
7.
(Optional) Remove the Hot Surface Ignitor (HSI) and
bracket with ignitor gasket
8. Check ignitor resistance. Nominal resistance is 40 to 70
ohms at room temperature and is stable over the life of the
ignitor.
9. Clean the flame sensor with fine steel wool (0000 grade).
Do not use sand paper or emery cloth.
1. Install the Hot Surface Ignitor (HSI) and bracket with
ignitor gasket into burner assembly.
2. Install flame sensor into burner assembly.
3. When installing the HSI and flame sensor, ¼" screws that
are the same size of those removed must be used. Do not
use longer screws.
4. Connect the wire for the flame sensor.
5. Connect the wire for the Hot Surface Ignitor.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection
of leaks to check all connections. A fire or explosion may
result causing property damage, personal injury or loss of
life.
6. Turn gas on at electric switch on gas valve and at external
shut-off or meter
7. Turn power on at external disconnect, fuse or circuit
breaker.
8. Run the furnace through two complete heating cycles to
check for proper operation
9. Install control door when complete.
from the burner assembly.
441 01 1501 04
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