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Code Faults
Cause
of the
fault
Description
Checking / solution
L04
BURNER FAILURE
SU
Burner start-up failure
No ignition
4
Check the ignition transformer
4
Check the ignition electrode for
4
Check the high voltage wiring
4
Check the earthing
4
The safety control box on the burner is
defective. Replace the command and safety box.
No flame signal.
Air present in the oil circuit.
4
Check that the oil valve is actually open
4
Check that the flame detection cell is in good
condition
4
Check that there is no recirculation of flue gases
Flame present but the flame signal is weak
4
Check that the flame detection cell is correctly
aligned
4
Check the position and condition of the
combustion head
4
Check the oil supply
4
Check the ignition electrode for
4
Check the wiring on the ignition electrode
4
Check the earthing
The safety control box on the burner is defective
4
Replace the command and safety box
L05
DEF.INTERNAL
SU
Internal SU fault
The safety control box on the burner is defective
4
Check the burner’s safety control box
4
Replace the command and safety box
L06
DEF.SPEED.MOT
SU
Fault on the burner motor
The safety control box on the burner is defective
4
Check the burner’s safety control box
The burner motor is defective
4
Replace the burner motor
L07
DEF.T.WARM UP
SU
Preheating period exceeded
The reheat fuel oil is defective
4
Check the condition of the heater
The safety control box on the burner is defective
4
Replace the nozzle line
L08
PARASIT FLAME
SU
Detection of a parasite flame
Signal present whilst there is no flame. Unwanted
light.
4
Check that the flame detection cell is in good
condition
4
Replace the flame detection cell
Defective oil solenoid valve
4
Check the oil solenoid valve
4
Replace the solenoid valve
L09
OIL.PRES FAIL.
SU
Oil pressure over limit
4
Check the oil pressure sensor
L30
DEF.FLUE GAS
PRESSURE
PCU
The flue gas pressure switch
opened 5 times in 24 hours.
4
Check the level of fouling of the heating body.
Clean the heating body.
4
Check the burner settings
4
Check the tightness of the flue gas pipe.
Check the general condition of the flue.
4
Flue gas pressure switch defective
9. Troubleshooting
AFC 18 - AFC 24 - AFC 30
150
09/07/2015 - 300026439-07