Lincoln Impinger X2 Ovens with Push Button Controls 3240-2 - Manual (Page 8)

Impinger X2 – Analog Service Manual – Dom & Int’l 8
wiring back to the centrifugal switch of the burner
blower motor. If voltage is present, check for 24VAC at
pins #3 and #2 (pilot valve). If voltage is not present,
replace burner control. If the pilot valve is energized,
check to see that the high voltage igniter circuit is also
energized. To check, turn power off, disconnect the
igniter lead from the ignition control. Turn power on. If
no spark is visible, replace burner control. If a spark is
visible at burner control, proceed.
Pilot valve Check for 24VAC supplied to pilot valve. If no voltage is
present, trace wiring back to burner control. If voltage is
present, check for gas pressure at the pilot line
connection. If no gas pressure is present during
ignition, check for any blockage in the assembly. If
there are no obstructions, and there is gas supplied to
the oven, replace the gas valve.
No pilot flame If the ignition control is supplied with 24VAC and the
pilot valve and igniter circuits are energized, visually
check for a pilot flame. This may be done by looking
through the inspection view port on the end of the
burner. If no pilot flame is visible, check the pilot tube.
Pilot tube Check for gas pressure at the pilot tube. Disconnect
pilot tube at the burner And connect manometer to pilot
tube. If no gas pressure is present during ignition,
check for blockage of the pilot tube. If the pilot tube is
clear, proceed.
Pilot orifice If there is gas pressure at the pilot tube, check the pilot
orifice for blockage or obstructions. Replace pilot orifice
as needed.
Burner igniter Check the burner igniter head for any damage or
obstructions also check for frayed or broken wire.
Check spark gap, gap should be 3/32” If there is visible
damage, replace burner igniter.
NOTE: Flame should be
On at this time
Pilot flame, but no main flame Electronic temperature
control
Check for 120VAC supplied to electronic temperature
control at terminals #13 and #12. Of there is no voltage,
trace wiring back to the burner switch. Also check for
120VAC supplied to terminal #20 on the electronic
temperature control. If there is no voltage at terminal
#20, trace wiring back to terminal #13. Set temperature
control to maximum temperature and check for
120VAC output at terminal #21 and neutral. If 120VAC
is present at terminal #20 and neutral, and the unit is
not heating, refer to “Temperature regulation valve” for
next check. If 120 VAC is not present, proceed.
Thermocouple probe WITH POWER ON AND THERMOCOUPLE LEADS
ATTACHED TO THE ELECTRONIC TEMPERATURE
CONTROL: Measure the D.C. millivolt output of these
leads. Refer to chart in the “Removal, Installation and
Adjustment” section for proper readings. If these
readings are not achieved, replace thermocouple.
Burner control. Check for 24VAC supplied to main valve. If no voltage
is present, trace wiring back to burner control. If there is
no voltage output, replace burner control.
Main gas valve Check to see that the switch on the valve is in the “ON”
position. Check for 24VAC supplied to main valve. If
there is voltage present, check to see that valve is
opening. Connect manometer to pressure tap on outlet
side of valve. If there is voltage to the valve, but no
output gas pressure, replace the valve.