67
Displayed fault
code
System characteristics
Cause
Measures
377
Burner in a fault state
Post-processing of ionisa-
tion current calibration:
Stabilisation conditions for
post-calibration not met
Check gas type setting. If the fault
occurs repeatedly, replace the
HBMU heat management unit. See
chapter "Replacing the HBMU heat
management unit".
Reset the appliance.
378
Burner in a fault state
Flame loss during stabili-
sation or operating phase
■
Check gas supply (gas pressure
and gas flow switch).
■
Check flue gas recirculation.
■
Check for contamination of ioni-
sation electrode and burner
gauze assembly.
Reset the appliance.
379
Burner in a fault state
Flame signal not present
or insufficient
■
Check ionisation electrode con-
necting cable for damage and
firm seating.
■
Check ionisation electrode. Re-
place if necessary.
Reset the appliance.
380
Burner in a fault state
Flame is lost immediately
after flame formation (dur-
ing safety time)
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode and
burner gauze assembly:
■
Clearance to burner gauze as-
sembly
■
Contamination on electrode
Reset the appliance.
381
Burner in a fault state
Flame loss during operat-
ing phase
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode and
burner gauze assembly:
■
Clearance to burner gauze as-
sembly
■
Contamination on electrode
Reset the appliance.
382
Burner in a fault state
Fault counter has excee-
ded limit.
Reset the appliance. Work through
fault analysis using fault history.
383, 384
Burner in a fault state
Possible contamination of
gas line
■
Check gas line for contamination.
■
Check the gas supply pressure.
■
Replace gas fan if necessary.
Reset the appliance.
385
Burner in a fault state
Short circuit, signal 1, ioni-
sation current
HBMU heat management
unit faulty
Check IO electrode for earth fault.
If the fault persists, replace the
HBMU heat management unit.
Reset the appliance.
Troubleshooting
Fault messages
(cont.)
6179762
Diagnosis
