Technical Service Manual
MKG Series Gas Griddles
Page 10
L22-296 Rev 0 (4/08)
Photo 18
•
If no spark is evident, check for 115 VAC to the
ignition module between terminal L1 and
chassis ground, also verify all other ground
connections, See Photo 17.
•
If 115 VAC
IS NOT
present at the ignition
module, check that the external power cord is
plugged in to live 115V outlet, and the fuse in
the yellow fuse holder (C) is good.
•
If 115 VAC
IS
present at the ignition module,
but no spark generated, replace the ignition
module, See Section 4.3.
4.2.3
Insufficient or Absence of Flame:
•
An insufficient pilot flame can result in a loss of
flame sense to the ignition module on a
Matchless ignition appliance, or loss of
sufficient millivoltage to actuate a Snap Action
appliance.
•
The tips of the pilot flame originating from the
pilot hood(A), should visibly extend above each
pilot runner tube(B). If flame is not visible, the
ignition system may fail to activate the main
burner system See Photo 18.
•
Common causes of insufficient pilot flame are
NO,
or
LOW
gas supply pressure, a pilot orifice
that has become clogged with foreign debris.
•
Verify gas pressure at the manual shut off
valves, (C), in Photo 1 for Snap Action models,
and (C), in Photo 2a for Matchless Ignition
models. The table in Section. 1.3.1 has the
nominal gas pressure for each gas type.
•
Pilot orifices can be checked by disconnecting
the ¼” tubing from the pilot assembly, (D, in
Photo 14 for Snap Action, and D, in Photo 16,
for Matchless Ignition models. Refer to section
4.4 for pilot removal from the appliance.
•
The gas flow to the pilot can be checked by
connecting a manometer to the disconnected
¼” tubing going to the pilot. Refer to Section 2
for each model to initiate gas flow to the pilot.
4.2.4
Pilot Lock-in: Snap Action Series
If a sufficient pilot flame is present, but the
main valve will not engage, check the millivolt
output of the thermocouple (F, in Photo 14) .
Disconnect the thermocouple contact (D, in
Photo 41) from the safety valve and measure
the output between the contact and ground.
Open circuit output should be greater than
15mv. closed circuit should be greater than
8mv (thermocouple connected).
Note
: To measure a closed circuit use of a
thermocouple test adapter. The thermocouple
contact must not be cross threaded, and must
be tightened to1/4-1/2 turn past finger tight.
•
If the millivolt output does not meet the
minimum voltage, replace thermocouple.
•
If the thermocouple is properly connected, and
the millivolt output is sufficient (25-35mV, No
Load), but safety valve will not engage,
replace the safety valve, see section 4.11.
•
If pilot flame and millivolt readings are normal
but there is no flame at the main burner, check
thermostat operation, refer to section 4.9.1.
4.2.5
Pilot Lock-in- Matchless Series (E & ST)
•
The electronic ignition system is an integral
flame sense system. This means that the
module supplies spark, and senses flame
current with the same electrode. The pilot
assembly, ignition module, and the appliance
must be properly grounded to operate
properly.
•
The ignition module is grounded to the chassis
directly at the pilot bracket (A, in Photo 20)
.
The appliance is equipped with a NEMA 5-15
grounded plug, extension cords are not
recommended for use with the appliance.
•
When properly grounded, and adequate pilot
flame are established as described in section
4.2.2, but spark continues for 90 seconds
followed by an ignition module lock out, there
is a flame sense failure. Replace the ignition
module as described in section 4.3.
4.3
IGNITION MODULE REPLACEMENT
•
The ignition modules are mounted in the unit,
but the replacement procedure is identical for
all ignition modules, See Photo 19.
•
Remove the two- (2) screws(A) holding the
ignition module mounting plate in place.
•
Remove module from mounting plate.
•
Disconnect ignition wire(B), and control
wiring(C) by carefully pulling upward on the
wire terminals with electrical pliers. To rewire
the ignition module correctly, it is advised to
label the wires. Miswiring the ignition module
may result in injury, or damage the appliance.
•
Mount the new module to the mounting plate.
•
Remount the assembly.
8
