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22
Clean Outside Coil (Qualified Servicer Only)
The coil with the outside air flowing over it should be inspected
annually and cleaned as frequently as necessary to keep the finned
areas free of lint, hair and debris.
Flame Sensor (Qualified Servicer Only)
A drop in the flame current can be caused by a nearly invisible
coating on the flame sensor. This coating, created by the fuel or
combustion air supply, can be removed by carefully cleaning the
flame sensor with steel wool.
NOTE:
After cleaning, the microamp signal should be stable and in
the range of 4 - 6 microamps DC.
Flue Passages (Qualified Servicer Only)
At the start of each heating season, inspect and, if necessary, clean
the unit flue passage.
Inspection & Cleaning
All flue product carrying areas of the furnace, its vent system, and
main burners should be examined by a qualified service agency be-
fore the start of each heating season. This examination is necessary
for continued safe operation. Particular attention should be given
to deterioration from corrosion or other sources. This examination
is accomplished in the following manner.
1. Disconnect power to the unit and remove furnace section
access panel.
2. Remove burner assembly:
a. Disconnect the three wires from the gas valve after noting
which wires are connected to each terminal.
b. Disconnect wires from the flame rod and ignition
electrode.
c. Disconnect the gas piping at the union.
d. The entire burner assembly can now be removed from
the unit.
NOTE:
Use all screws that were removed; they are necessary for
safe and proper operation of the unit.
3. Inspect and periodically clean the vent outlet (bird screen)
on the access panel.
NOTE:
Periodic observation of the flame and a log of C0
2
measurements are recommended. This will aid in determining
whether the furnace is operating efficiently or if the furnace
requires cleaning.
Flames should be stable, soft and blue (dust may cause orange tips
but must not be yellow). The flames must extend directly outward
from the burner without curling, floating or lifting off.
BURNER FLAME
T
O
AVOID
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECTRIC
SHOCK
,
DO
NOT
REMOVE
ANY
INTERNAL
COMPARTMENT
COVERS
OR
ATTEMPT
ANY
ADJUSTMENT
. C
ONTACT
A
QUALIFIED
SERVICER
AT
ONCE
IF
AN
ABNORMAL
FLAME
SHOULD
DEVELOP
.
WARNING
At least once a year, prior to or during the heating season, make a
visual check of the burner flames.
NOTE:
This will involve removing and reinstalling the heat exchanger
door on the unit, which is held by two screws. If you are uncertain
about your ability to do this, contact a qualified servicer.
If a strong wind is blowing, it may alter the airflow pattern within the
unit enough that an inspection of the burner flames is not possible.
Functional Parts
Refer to the unit Parts Catalog for a list of functional parts. Parts
are available from your distributor.
TROUBLESHOOTING
Ignition Control Error Codes
The following presents probable causes of questionable unit op-
eration. Refer to
Diagnostic Indicator Chart
for an interpretation
of the signal and to this section for an explanation.
Remove the control box access panel and note the number of
diagnostic LED flashes. Refer to
Diagnostic Indicator Chart
for an
interpretation of the signal and to this section for an explanation.
Internal Control Failure
If the integrated ignition control in this unit encounters an internal
fault, it will go into a “hard” lockout and turn off the diagnostic LED.
If diagnostic LED indicates an internal fault, check power supply to
unit for proper voltage, check all fuses, circuit breakers and wiring.
Disconnect electric power for five seconds. If LED remains off after
restoring power, replace control.
Abnormal Operation - Heating Codes
External Lockout
(1 FLASH CODE)
An external lockout occurs if the integrated ignition control deter-
mines that a measurable combustion cannot be established within
three (3) consecutive ignition attempts. If flame is not established
within the seven (7) second trial for ignition, the gas valve is deen-
ergized, 15 second inter-purge cycle is completed, and ignition is
reattempted. The control will repeat this routine three times if a
measurable combustion is not established. The control will then
shut off the induced draft blower and go into a lockout state.
If flame is established but lost, the control will energize the cir-
culator blower at the heat speed and then begin a new ignition
sequence. If flame is established then lost on subsequent attempts,
the control will recycle for four (4) consecutive ignition attempts
(five attempts total) before locking out.