16
MN-111 | Service book | Errors and Troubleshooting MN-111 ENG Rev08 | 2019/06/21 | © 2019 W&H Sterilization Srl
Errors
Code
Description
Possible causes
Checks and actions
424
H20 overconsumption during
HEA2 phase (starting from the
beginning of the
cycleH20>600cc).
Water pump failure
See Test instructions service book, chapter SPECIFIC TESTS FOR INDIVIDUAL
COMPONENTS, Water pump. Replace the water pump if needed.
Check/priming ULKA valve failure.
See Test instructions service book, chapter SPECIFIC TESTS FOR INDIVIDUAL
COMPONENTS, Water pump. Replace the ULKA valve if needed.
Failure of the clean water MIN
level sensor.
See Test instructions service book, chapter SPECIFIC TESTS FOR INDIVIDUAL
COMPONENTS, Water level sensors. Replace the sensor if needed.
S.G. temperature sensor failure
See Test instructions service book, chapter SPECIFIC TESTS FOR INDIVIDUAL
COMPONENTS, Steam generator temperature sensor.
Replace the sensor if needed.
Main board failure
See Test instructions service book, chapter SPECIFIC TESTS FOR INDIVIDUAL
COMPONENTS:
n
Water pump (step 3), or
n
Heating element of the steam generator and safety thermostat (step 2), or
n
Steam generator temperature sensor (steps 2, 5 and 6).
Replace the main board if needed.
430
Fan error.
Fan disconnected.
Check the connection to the board and the relevant wires.
Fan blade jammed.
See Test instructions service book, chapter DIAGNOSTIC CYCLE/LEAKAGE TESTING (2),
Diagnostic cycle: fan tests (step 2).
Fan motor failure.
Run diagnostic cycle Fan Test.
Follow the instructions given on MN-111’s screen. Replace component if needed.
Main board failure.
If the problem persists, replace the main board.
520
Door locking timeout.
Microswitch disconnected
(LOCKED position).
Check the connections between the microswitch (LOCKED position) and the main board
and the relevant wires. If the problem persist, see next step.
Microswitch failure (LOCKED
position).
Main board failure.
See Test instructions service book, chapter SPECIFIC TEST FOR INDIVIDUAL COMPONENTS,
Door locking system - automatic mode, Door locking system - manual mode.
Replace the microswitch if needed.
If the problem persists, check the continuity of the cables from the microswitch to the
main board.
If the problem persists, replace the main board.
521
No current through the door
locking motor.
Motor disconnected.
Check the connections between the motor, the pressure switch and the main board.
Main board failure
(current detection or motor
supply).
See Test instructions service book, chapter SPECIFIC TEST FOR INDIVIDUAL COMPONENTS,
Door locking system - automatic mode, Door locking system - manual mode.
If the motor rotates, but the problem persists replace the main board. Otherwise see
next step.
Cable failure.
Check the integrity of the relevant wires. If needed replace cables.
Motor failure.
See Test instructions service book, chapter SPECIFIC TEST FOR INDIVIDUAL COMPONENTS,
Door locking system - automatic mode, Door locking system - manual mode.
522
Door locking motor: too high
current at start (during door
closure)
Motor failure.
Main board failure.
See Test instructions service book, chapter SPECIFIC TEST FOR INDIVIDUAL COMPONENTS,
Door locking system - automatic mode, Door locking system - manual mode.
526
Unexpected position of the
microswitch (the door is locked
and the switch changes status)
Microswitch failure
Main board failure
Replace the door locking system, if the problem persists replace the main board.
Execution of the «Emergency»
manual door opening procedure.
See "Emergency door opening" on page 9.
527 - 531
Impossible position detected.
Microswitch failure.
Main board failure.
See Test instructions service book, chapter SPECIFIC TEST FOR INDIVIDUAL COMPONENTS,
Door locking system - automatic mode, Door locking system - manual mode.
529
Unexpected pressure during door
opening.
Pressure sensor failure.
See error "120-121" on page 11.
532
Door locking motor: too high
current at start (during door
opening)
Motor failure.
Main board failure.
See error "522" above.
533
Door unlocking timeout.
Wrong microswitch connection
(OPEN side).
Microswitch failure (OPEN side).
Main board failure.
Proceed as per errors "527 - 531" above, but only with the OPEN side microswitch.
534
Impossible position detected.
See error "Errors" on page 10.
