Viessmann VITODENS 222-F Installation And Service Instructions Manual page 80

Troubleshooting
Fault messages
(cont.)
Fault number System characteristics
on the display
F.375 Burner in a fault state
80
Cause
Performing ionisation cur-
rent calibration: Calibra-
tion not performed. Mini-
mum value or termination
criterion not reached.
Measures
Check ionisation electrode and
connecting cable. Check plug-in
connections for loose contacts.
Check flue system; remove flue
gas recirculation if required.
Check system for condensate
backup.
Visually inspect gas train inlet and
strainer on the inlet side for con-
tamination.
Note
To prevent water damage, detach
fan unit before removing the burn-
er.
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).
If burner gauze assembly and ioni-
sation electrode have been re-
placed, also clean fan unit, gas/air
channel and Venturi extension.
Reset the appliance.