Error code
Description
or
CSU time out:
Bad connection: check the wiring and connectors.
Faulty CSU: replace CSU
Communication error with the safety PCB:
Bad connection: check the wiring and connectors.
Control unit failure: replace the control unit
Safety parameters not OK:
Bad connection: check the wiring and connectors.
Flow temperature sensor short circuited:
Bad connection: check the wiring and connectors.
Incorrectly fitted sensor: check that the sensor has been correctly fitted
Faulty sensor: replace the sensor
Flow temperature sensor open:
Bad connection: check the wiring and connectors.
Incorrectly fitted sensor: check that the sensor has been correctly fitted
Faulty sensor: replace the sensor
Flow temperature sensor deviation:
Bad connection: check the connection
Faulty sensor: replace the sensor
Air pressure differential switch activated:
Bad connection: check the wiring and connectors.
Pressure in flue gas duct is or was too high:
Non-return valve does not open
Siphon blocked or empty
Check that the air supply inlet and flue gas outlet are not blocked
Check the cleanliness of the heat exchanger
Five failed burner starts:
No ignition spark:
Check the wiring between the PCU electronic PCB and the ignition transformer
Check that the SU electronic PCB is correctly in place
Check the ionisation/ignition electrode
Check breakdown to earth
Check the condition of the burner cover
Check the earthing
SU electronic PCB faulty: replace the electronic PCB
Ignition spark but no flame:
Vent the gas pipes to remove air
Check that the air supply inlet and flue gas outlet are not blocked
Check that the gas valve is fully opened
Check the gas supply pressure
Check the operation and setting of the gas valve unit
Check the wiring on the gas valve unit
SU electronic PCB faulty: replace the electronic PCB
Presence of the flame but insufficient ionization (<4 µA):
Check that the gas valve is fully opened
Check the gas supply pressure
Check the ionisation/ignition electrode
Check the earthing
Check the wiring on the ionisation/ignition electrode
False flame signal:
The burner remains very hot: Set the O
2
Ionisation current measured but no flame should be present: check the ionisation/ignition electrode
Faulty gas valve: replace the gas valve
Faulty ignition transformer: replace the ignition transformer
Fan fault:
Bad connection: check the wiring and connectors.
Fan operates when it should not be operating: check for excessive chimney draught
Faulty fan: replace the fan
8 Troubleshooting
7616014 - v.03 - 15022016
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