Viessmann Vitodens 050-W Installation And Service Instructions Manual page 64

Troubleshooting
Fault messages
(cont.)
Displayed fault System characteristics
code
366, 367 Burner in a fault state
369 Burner in a fault state
370 Burner in a fault state
371 Burner in a fault state
372 Burner in a fault state
64
Cause
Gas valve power supply
does not turn off.
Flame is lost immediately
after flame formation (dur-
ing safety time)
Gas valve or modulation
valve does not close.
Fan speed too low
Repeated flame loss dur-
ing calibration
Measures
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.
Check the fan.
Check the fan connecting cables.
Check the fan power supply.
Reset the appliance.
Check ionisation electrode and
■
connecting cable.
Check plug-in connections for
■
loose contacts.
Check the flue system. Remove
■
flue gas recirculation if necessa-
ry.
Check system for condensate
■
backup.
Visually inspect gas solenoid
■
valve inlet and inlet strainer for
contamination.
Note
To prevent water damage, detach
fan unit before removing the burn-
er. Deposits on the electrodes indi-
cate foreign bodies in the combus-
tion air.
Check the installation room and
flue system for causes of the de-
posits. For example laundry deter-
gents, cleaning agents, toiletries,
deposits in the ventilation air sup-
ply (chimney). If burner gauze as-
sembly and ionisation electrode
have been replaced, also clean fan
unit, gas/air channel and Venturi
extension.
Reset the appliance.