DeDietrich MCA 45 User Manual page 47

MCA 45 - 65 - 90 - 115
Code Faults
L10 DEP-RET<MIN
L11 DEP-RET>MAX
L12 STB OPEN
BURNER FAILURE PCU
L14
L16 PARASIT FLAME
L17 VALVE FAIL
06/09/2010 - 300024828-001-A
Cause Description
of the
error
PCU Difference between the flow and
return temperatures insufficient
PCU Difference between the flow and
return temperatures too great
PCU Maximum boiler temperature
exceeded (STB thermostat
maximum)
5 burner start-up failures
PCU Detection of a parasite flame
PCU Problem on the gas valve
Checking / solution
Bad connection
Sensor fault
Contact the professional who takes care of
4
maintenance of the appliance
No water circulation
Vent the air in the heating system
4
Check the circulation (direction, pump,
4
valves)
Check the water pressure
4
Bad connection
Sensor fault
Contact the professional who takes care of
4
maintenance of the appliance
No water circulation
Vent the air in the heating system
4
Check the circulation (direction, pump,
4
valves)
Check the water pressure
4
Bad connection
Sensor fault
Contact the professional who takes care of
4
maintenance of the appliance
No water circulation
Vent the air in the heating system
4
Check the circulation (direction, pump,
4
valves)
Check the water pressure
4
Absence of ignition arch
Contact the professional who takes care of
4
maintenance of the appliance
Presence of the ignition arc but no flame formation
Check that the gas valve is fully opened
4
Contact the professional who takes care of
4
maintenance of the appliance
Presence of the flame but insufficient ionization
(<3 µA)
Check that the gas valve is fully opened
4
Contact the professional who takes care of
4
maintenance of the appliance
Ionisation current present when there should not
be a flame
Ignition transformer defective
Gas valve defective
The burner remains very hot: CO
Contact the professional who takes care of
4
maintenance of the appliance
Bad connection
SU PCB faulty
Contact the professional who takes care of
4
maintenance of the appliance
7. Troubleshooting
too high
2
46