DeDietrich MCA 45 User Manual page 48

7. Troubleshooting
Code Faults
L34 FAN FAILURE
L35 BACK>BOIL FAIL
L36 I-CURRENT FAIL
L37 SU COM.FAIL
L38 PCU COM.FAIL
L39 BL OPEN FAIL
L40 TEST.HRU.FAIL
L250 DEF.WATER MIS.
L251 MANOMETRE FAIL PCU
D03 OUTL S.B FAIL.
D04 OUTL S.C FAIL.
47
Cause Description
of the
error
PCU The fan is not running at the right
speed
PCU Flow and return reversed
PCU The flame went out more than 5
times in 24 hours while the burner
was operating
PCU Communication failure with the SU
PCB
PCU Communication failure between the
PCU and SCU PCBs
PCU The BL inlet opened for a short time Bad connection
PCU HRU/URC unit test error
PCU The water pressure is too low
Fault on the water pressure sensor Wiring problem
SCU Sensor fault flow circuit B
Sensor fault flow circuit C
Remarks:
The circuit pump is running.
The 3-way valve motor on the circuit
is no longer powered and can be
adjusted manually.
Checking / solution
Bad connection
Fan defective
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
Sensor fault
Contact the professional who takes care of
4
maintenance of the appliance
Water circulation direction reversed
Check the circulation (direction, pump,
4
valves)
No ionization current
Check that the gas valve is fully opened
4
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
SCU PCB not connected or faulty
Contact the professional who takes care of
4
maintenance of the appliance
External cause
Parameter incorrectly set
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
External cause
Parameter incorrectly set
Contact the professional who takes care of
4
maintenance of the appliance
Hydraulic circuit incorrectly vented
Water leak
Measurement error
Top up with more water if necessary
4
Reset the boiler
4
The manometer is defective
Sensor pcb defective
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
Sensor fault
Contact the professional who takes care of
4
maintenance of the appliance
06/09/2010 - 300024828-001-A
MCA 45 - 65 - 90 - 115