Viessmann B1HF Installation And Service Instructions Manual page 74

Troubleshooting
Fault messages
(cont.)
Displayed fault System characteristics
code
361 Burner in a fault state
365 Burner in a fault state
366, 367 Burner in a fault state
369 Burner in a fault state
370 Burner in a fault state
74
Cause
Flame signal is not
present or insufficient at
burner start.
Gas valve relay contact
feedback implausible (re-
lay contact is "welded up")
Gas valve electricity sup-
ply does not turn off.
Flame is lost immediately
after flame formation (dur-
ing safety time)
Gas valve or modulation
valve will not close.
Measures
Check ionisation electrode and
connecting cable. Check plug-in
connections for loose contacts.
Note
Deposits on the electrodes indicate
foreign bodies in the combustion
air. Check the installation room and
flue system for causes of the de-
posits. For example: Laundry de-
tergents, cleaning agents, toilet-
ries, deposits in the ventilation air
supply (chimney)
Reset the appliance.
Replace the HBMU heat manage-
ment unit.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode for the
following:
Clearance to burner gauze as-
■
sembly.
Contamination on electrode
■
Reset the appliance.
Reset the appliance.
If fault occurs repeatedly, replace
fan unit.