GPG14M Service Manual

SERVICING
60
L2
INDUCER
LOW
HIGH
L1
ODF
LOW
HIGH
T1
Q3
K4
K3 K5
K6
T2
K7
FS
U1
U2
U6
U7
U4
U5
U3
P2
K2
K1
ECON
STAGE
DELAY
C9
SPEED UP
SW1
FAULT
RECALL
BLOWER
OFF
DELAY
F1
R C W1W2 G Y2
90
120
150
180
10MIN
5 MIN
NONE
PARK
1
2
3
4
5
Y1
PCBAG127 DSI Control Board
S-314 CHECKING FLAME SENSOR
A flame sensing device is used in conjunction with the ignition
control module to prove combustion. If a microamp signal is
not present the control will de-energize the gas valve and
"retry" for ignition or lockout.
DSI Direct Spark Ignition Systems
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Disconnect the flame sensor wire from terminal FS of the
ignition control module.
Flame
Sensor
Flame Sensor
2. Connect a microamp meter in series with this wire and
terminal FS.
3. Be sure the negative side of the meter is to the wire and
the positive of the meter is to terminal FS.
4. Turn on Power.
WARNING
Line Voltage now present.
5. With Power ON, Place the unit into a heating cycle.
6. As soon as flame is established a microamp reading
should be evident once proof of flame (microamp reading)
is established, the hot surface ignitor will be de-ener-
gized.
7. The nominal microamp reading is 4 microamps.
8. If the microamp current is less than 0.5 microamp the
control will lockout and flash a code of 1 flash after
attempting to reestablish flame sense.
9. If the microamp reading is less than the minimum speci-
fied, check for high resistance wiring connections, the
distance (3/16") between the sensor and burner, flame
sensor connections, dirty flame sensor or poor ground-
ing.
10. If no reading, check for continuity on all components and
if good - replace ignition control module.
NOTE: Contaminated fuel or combustion air can create a
nearly invisible coating on the flame sensor. This coating
works as an insulator causing a loss in the flame sense
signal. If this situation occurs the flame sensor must be
cleaned with steel wool. Do not use sand paper, the silicone
in sand paper will further contaminate the sensor.