Owner's manual

Code Faults Cause
of the
fault
Description Checking / solution
L14 BURNER FAILURE
PCU 5 burner start-up failures No ignition
4 Contact the professional who takes care of
maintenance of the appliance
Ignition arc, but no flame formation
4 Check that the gas valve is fully opened
4 Contact the professional who takes care of
maintenance of the appliance
Presence of the flame but insufficient ionization
(<3 µA)
4 Check that the gas valve is fully opened
4 Contact the professional who takes care of
maintenance of the appliance
L16
PARASIT FLAME
PCU Detection of a parasite flame Ionization current present when there should not
be a flame
Ignition transformer defective
Gas valve defective
The burner remains very hot: CO
2
too high
4 Contact the professional who takes care of
maintenance of the appliance
L17 VALVE FAIL
PCU Problem on the SU PCB Bad connection
SU PCB faulty
4 Contact the professional who takes care of
maintenance of the appliance
L34 FAN FAILURE
PCU The fan is not running at the right
speed
Bad connection
Fan defective
4 Contact the professional who takes care of
maintenance of the appliance
L35 BACK>BOIL FAIL
PCU Flow and return reversed Bad connection
Sensor fault
4 Contact the professional who takes care of
maintenance of the appliance
Water circulation direction reversed
4 Check the circulation (direction, pump,
valves)
L36 I-CURRENT FAIL
PCU The flame went out more than 5
times in 24 hours while the burner
was operating
No ionization current
4 Check that the gas valve is fully opened
4 Contact the professional who takes care of
maintenance of the appliance
L37
SU COM.FAIL
PCU Communication failure with the SU
PCB
Bad connection
4 Contact the professional who takes care of
maintenance of the appliance
L38 PCU COM.FAIL
PCU Communication failure between the
PCU and SCU PCBs
Bad connection
SCU PCB not connected or faulty
4 Contact the professional who takes care of
maintenance of the appliance
L39 BL OPEN FAIL
PCU The BL inlet opened for a short time Bad connection
External cause
Parameter incorrectly set
4 Contact the professional who takes care of
maintenance of the appliance
6. Troubleshooting MCA 15 - MCA 25 MCA 25/28 MI
37
15/06/12 - 300022161-001-01