GMES8 GCES8 Service Manual

54
SERVICING
COOL-H
PAR K PAR K
S-314 CHECKING FLAME SENSOR
A ame sensing device is used in conjunction with the ignition
control module to prove combustion. If proof of ame is not
present the control will de-energize the gas valve and "retry"
for ignition or lockout.
The following drawings illustrate from a bottom view, the
approximate distances for the ignitor and ame sensor to
the gas inshot burner. You will note they are in the main
burner stream, not in the carry over ports as shown in the
following gure.
Flame Sensor
Models with Integrated Ignition
Control & Flame Sensor Probe
(80% Upow Model Shown, Counterow Similar)
WARNING
HIGH VOLTAGE
D
ISCONNECT
ALL
POWER BEFORE SERVICING OR
INSTALLING THIS UNIT.
M
ULTIPLE POWER SOURCES MAY
BE PRESENT.
F
AILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
1. Disconnect the orange ame sensor wire from the sensor
.
2. Connect a micro-amp meter in series with this wire and
the sensor terminal.
3. Place the unit into a heating cycle.
L
INE VOLTAGE NOW PRESENT
WARNING
4. As soon as ame is established a micro-amp reading
should be evident once proof of ame (micro-amp read-
ing) is established, the hot surface ignitor will be de-en-
ergized.
5. The Integrated Ignition controls will have 1 to 4 mi-
cro-amps. If the micro-amp reading is less than the
minimum specied, check for high resistance wiring
connections, sensor to burner gap, dirty ame sensor,
or poor grounding.
6. If absolutely no reading, check for continuity on all com-
ponents and if good - replace ignition control module.
NOTE: Contaminated fuel or combustion air can create a
nearly invisible coating on the ame sensor. This coating
works as an insulator causing a loss in the ame sense sig-
nal. If this situation occurs the ame sensor must be cleaned
with steel wool.