DeDietrich AFC 18 User Manual page 34

8 Troubleshooting
Code Faults
L08 PARASIT FLAME
L09 OIL.PRES FAIL.
L30 SMOKE
PRE.FAIL
L31 DEF.SMOKE.TE
MP
L32 DEF.OUTLET S.
L33 DEF.OUTLET S.
L34 BACK S.FAILURE PCU The return temperature sensor
L35 BACK S.FAILURE PCU The return temperature sensor
L36 DEF.FLAME LOS
L37 SU COM.FAIL
L38 PCU COM.FAIL
L39 BL OPEN FAIL
L250 DEF.WATER MIS. PCU The water pressure is too low
L251 MANOMETRE
FAIL
34 AFC
Cau Description
se of
the
fault
SU Detection of a parasite flame
SU Oil pressure exceeds limit
PCU The flue gas pressure switch
opened five times in 24 hours.
PCU The maximum flue gas temper­
ature was exceeded five times
in 24 hours.
PCU The boiler flow sensor has short
circuited
PCU The boiler flow sensor is on an
open circuit
has short circuited
is on an open circuit
PCU Three flame losses during a
heating demand
PCU Communication failure with the
safety box
PCU Communication failure between
the PCU and SCU PCBs.
PCU The BL input opened for a short
period of time
PCU Fault on the water pressure
sensor
Check/solution
Signal present whilst there is no flame
Contact the professional who handles the mainte­
nance for the appliance
Contact the professional who handles the mainte­
nance for the appliance
Contact the professional who handles the mainte­
nance for the appliance
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
Sensor failure
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
Sensor failure
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
Sensor failure
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
Sensor failure
Contact the professional who handles the mainte­
nance for the appliance
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
SCU PCB not connected or defective.
Contact the professional who handles the mainte­
nance for the appliance
Poor connection
External cause
Incorrectly set parameter
Contact the professional who handles the mainte­
nance for the appliance
Hydraulic circuit incorrectly vented
Water leak
Measurement error
Contact the professional who handles the mainte­
nance for the appliance
Wiring problem
Water pressure sensor defective
Sensor PCB defect
Contact the professional who handles the mainte­
nance for the appliance
300026440 - v06 - 07082018