DeDietrich MCA 45 - Page 47

Code Faults Cause
of the
error
Description Checking / solution
L10 DEP-RET<MIN
PCU Difference between the flow and
return temperatures insufficient
Bad connection
Sensor fault
4 Contact the professional who takes care of
maintenance of the appliance
No water circulation
4 Vent the air in the heating system
4 Check the circulation (direction, pump,
valves)
4 Check the water pressure
L11 DEP-RET>MAX
PCU Difference between the flow and
return temperatures too great
Bad connection
Sensor fault
4 Contact the professional who takes care of
maintenance of the appliance
No water circulation
4 Vent the air in the heating system
4 Check the circulation (direction, pump,
valves)
4 Check the water pressure
L12 STB OPEN
PCU Maximum boiler temperature
exceeded (STB thermostat
maximum)
Bad connection
Sensor fault
4 Contact the professional who takes care of
maintenance of the appliance
No water circulation
4 Vent the air in the heating system
4 Check the circulation (direction, pump,
valves)
4 Check the water pressure
L14 BURNER FAILURE
PCU 5 burner start-up failures Absence of ignition arch
4 Contact the professional who takes care of
maintenance of the appliance
Presence of the 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 Ionisation 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 gas valve Bad connection
SU PCB faulty
4 Contact the professional who takes care of
maintenance of the appliance
MCA 45 - 65 - 90 - 115 7. Troubleshooting
06/09/2010 - 300024828-001-A
46