Code
Description
Solution
E04.10
5 Unsuccessful burners starts detected
Five failed burner starts:
No ignition spark:
Check the wiring between the CU-GH PCB and
the ignition transformer
Check the ionisation/ignition electrode
Check breakdown to earth
Check the condition of the burner cover
Check the earthing
SU PCB faulty: replace the SU 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
Replace the CU-GH PCB
Flame present, but ionisation has failed or is inade
quate:
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 elec
trode.
E04.11
VPS Gas Valve proving failed
Gas leakage control fault:
Bad connection: check the wiring and connectors
Gas leakage control VPS faulty: Replace the GPS
Gas valve unit faulty: Replace the gas valve unit
E04.12
False flame detected before burner start
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
E04.13
Fan speed has exceeded normal operating range
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
E04.15
The flue gas pipe is blocked
Flue gas outlet is blocked:
Check that the flue gas outlet is not blocked
Restart the boiler
E04.17
The driver for the gas valve is broken
Gas valve unit fault:
Bad connection: check the wiring and connectors
Faulty gas valve unit: Replace the gas valve unit
E04.23
Gas Valve Control internal locking
Restart the boiler
Replace the CU-GH PCB
11.2 Error memory
The boiler control unit has an error memory. It stores the last 32 errors that
have occurred.
11 Troubleshooting
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7665063 - v.05 - 18102018
