Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors page 125

Fault messages on the gas condensing...
Control unit System characteristics
message
F.375 Burner in a fault state
(cont.)
Cause
Ionisation current calibra-
tion type: Calibration not
performed. Minimum val-
ue or termination criterion
not reached.
Troubleshooting
Measures
Check ionisation electrode and
connecting cable. Check plug-in
connection for loose connections.
Check flue system or flue gas re-
circulation.
Check if condensate banked.
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 device.
125