Service manual

120 800170
Section 3 Troubleshooting (MDC Models – Dryer Control)
© Copyright, Alliance Laundry Systems LLC – DO NOT COPY or TRANSMIT
66. NO HEAT (GAS)
Is there
voltage across
the pink wire of the gas
valve to terminal 2 on
the motor?
Is there
voltage at the
output of the limit
thermostat referenced
to neutral?
Is there
voltage to the
input of the limit
thermostat referenced
to neutral?
Is there
voltage across
FS-1 and H2-3
(neutral) on the
control?
Is there
voltage across
FS-2 and H2-3
(neutral) on the
control?
Is there voltage across
terminal 1 of the motor
and L1?
Check for proper
operation of
centrifugal on the
motor. Replace
motor if necessary.
Correct wiring
to the motor.
Make sure unit
is calling for heat.
Check operation
of thermistor.
Replace control.
Correct wiring
between FS-1 and
limit thermostat.
Check for proper
air flow making
sure venting is
not blocked and
lint screen is clean.
Replace limit
thermostat.
Correct wiring
between
limit thermostat
and gas valve.
Refer to
NOTE.
(1)
(2)
(3)
(4)
(5)
(6)
YES
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
Refer to Door Open troubleshooting.
Replace either the
gas valve, coils of
gas valve or the
sensor.
NOTE:
When calling for heat the holding coil, the booster coil
and the igniter will be energized. Once the sensor
senses that the igniter is hot enough for ignition, it will
open. At this time the holding coil and the secondary
coil will be energized allowing gas to flow. If the flame
cycles on and off check for proper operation of sensor.
If gas never ignites, check for problems with the coil
and check to see if the sensor opens. If coils are good
and the sensor opens with the glow bar operational
and there is no ignition/gas flow, replace the gas valve.
No
Heat
Gas
Dwg. 7
DRY361_S