Viessmann B2TF Installation And Service Instructions Manual page 88

Troubleshooting
Fault messages
(cont.)
Displayed fault System characteristics
code
F.377 Burner in a fault state
F.378 Burner in a fault state
F.379 Burner in a fault state
F.380 Burner in a fault state
F.381 Burner in a fault state
F.382 Burner in a fault state
F.383 Burner in a fault state
F.384 Burner in a fault state
F.385 Burner in a fault state
88
Cause
Post-processing ionisation
current calibration: Stabili-
sation conditions for post-
calibration not reached
Flame loss during stabili-
sation or operating phase
Flame signal not present
or insufficient
Flame is lost immediately
after flame formation (dur-
ing safety time)
Flame loss during operat-
ing phase
Fault counter has excee-
ded limit.
Possible contamination of
gas line
Possible contamination of
gas line
Short circuit, signal 1, ioni-
sation current.
BCU burner control unit
faulty.
Measures
Check gas type setting. If fault re-
curs, replace BCU burner control
unit: See page 100.
Reset the appliance.
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.
Check ionisation electrode con-
■
necting cable for damage and
ensure it is secure.
Check ionisation electrode, re-
■
place if necessary.
Reset the appliance.
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode, burner
gauze assembly:
Clearance to burner gauze as-
■
sembly
Contamination on electrode
■
Reset the appliance.
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode, burner
gauze assembly:
Clearance to burner gauze as-
■
sembly.
Contamination on electrode
■
Reset the appliance.
Reset the appliance. Work through
fault analysis using fault history.
Check gas line for contamination.
■
Check the gas supply pressure.
■
Replace gas fan if required.
■
Reset the appliance.
Check gas line for contamination.
■
Check the gas supply pressure.
■
Replace gas fan if required.
■
Reset the appliance.
Check IO electrode for earth fault.
If fault persists, replace BCU burn-
er control unit: See page 100.
Reset the appliance.