International comfort products A Series Installation Instructions Manual page 56

WARNING
!
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower door switch opens 115- -v power to control. No
component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch for
service purposes.
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:
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.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
When servicing the flame
factory- -provided 1/4-in. length screws. Use of alternate
screws will damage unit components.
Fig. 66 - - Igniter Position - - Back View
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 burner assembly.
a. Using a 1/4- -in. driver, remove the screw securing the flame
sensor to the burner assembly (Fig. 66). Retain factory- -
provided 1/4- -in. screws.
b. Carefully withdraw the flame sensor from the burner as-
sembly without striking the sensor on surrounding parts.
c. Inspect flame sensor for signs of damage or failure.
56
sensor, only use the
A190266
Specifications subject to change without notice.
d. Clean the flame sensor with fine steel wool (0000 grade).
Do not use sand paper or emery cloth.
e. If replacement is required, remove the screw that secures
the flame sensor on the bracket and remove the flame
sensor.
7. To replace flame sensor and bracket assembly, reverse items
6.a. through 6.d.
8. Reconnect flame sensor wire to the wire harness, dressing
the sensor wires to ensure there is no tension on the flame
sensor itself (Fig. 66).
! 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.
9. Turn gas on at electric switch on gas valve and at external
shut-off or meter
10. Turn power on at external disconnect, fuse or circuit
breaker.
11. Run the furnace through two complete heating cycles to
check for proper operation
12. Install control door when complete.
Servicing Hot Surface Igniter
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
When servicing the flame
factory- -provided 1/4-in. length screws. Use of alternate
screws will damage unit components.
The igniter does NOT require annual inspection. Check igniter
resistance before removal (Fig. 66).
1. Turn off gas and electrical supplies to furnace.
2. Remove control door.
3. Disconnect igniter wire connection.
4. Check igniter resistance. Igniter resistance is affected by
temperature. Only check resistance when the igniter is at
room temperature.
a. Using an ohm meter, check resistance across both igniter
leads in connector.
b. Cold reading should be between 40 ohms and 70 ohms.
5. Remove igniter assembly.
a. Using a 1/4- -in. driver, remove the two screws securing the
igniter mounting bracket to the burner assembly (Fig. 66).
Retain 1/4- -in. length screws.
b. Carefully withdraw the igniter and bracket assembly
through the burner assembly without striking the igniter on
surrounding parts.
c. Inspect igniter for signs of damage or failure.
d. Inspect the igniter gasket. If damaged or missing, replace
gasket before reinstalling.
6. To replace igniter and bracket assembly, reverse items 5.a.
through 5.d.
7. Reconnect igniter harness to the igniter, dressing the igniter
wires to ensure there is no tension on the igniter itself (Fig.
66).
sensor, only use the
440 01 4601 01