94
3064816_201804
40. Troubleshooting
Fault
code
Fault
Possible causes
Remedy
56
Calibration factory limit
Calibration factory limit (minimum) not
reached
Flue gas recirculation
Ionisation electrode corroded/bent
Wiring error on HCM-2 (low voltage
side)
Flue gas recirculation:
- Check flue path inside and outside the
appliance (leaking, blocked).
Have customer service set the IO default
value to
factory setting.
Ionisation electrode:
- Electrical wiring and connections.
- Check the condition of the electrode; clean
or replace if necessary.
- Adjust gap and position or replace if neces-
sary.
Check burner earthing.
Press reset button.
Check the electrical connection of the HCM-2
low voltage side
57
Calibration deviation
Ionisation electrode corroded/bent
Soot or dirt particles in the intake air
Flue gas recirculation
Wiring error on HCM-2 (low voltage
side)
Intake air:
- Soot or dirt particles in the intake air lead to
a calibration discrepancy (in room sealed
operation).
Ionisation electrode:
- Check electrical connections.
- Check the condition of the electrode; clean
or replace if necessary.
- Adjust gap and position or replace if neces-
sary.
- Carry out 100 % calibration.
Replace boiler coding card.
Check the electrical connection of the HCM-2
low voltage side
58
Calibration timeout
The heating appliance cannot carry out
calibration
Flue gas recirculation
Fan faulty
Inadequate heat transfer
Wiring error on HCM-2 (low voltage
side)
Flue gas recirculation:
- Check flue path inside and outside the
appliance (leaking, blocked).
Fan:
Check that the fan and its wiring are intact.
Inadequate heat transfer:
- Open heating circuits to ensure adequate
heat transfer.
Check IO electrode.
Press reset button.
Check the electrical connection of the HCM-2
low voltage side
59
Calibration factory limit
Calibration factory limit (maximum)
exceeded
Soot or dirt particles in the intake air
Flue gas recirculation
Wiring error on HCM-2 (low voltage
side)
Intake air:
Soot or other dirt particles in the intake air (in
room sealed operation).
Tightness test
Have customer service set IO default value
to factory setting
Check the electrical connection of the HCM-2
low voltage side
78
Header sensor faulty
Header sensor or sensor lead has short
circuit or lead break
Header sensor:
- Check leads and plug-in connections.
- If OK but no function, replace the sensor.
- Press reset button
