Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors page 132

Troubleshooting
Fault messages on the gas condensing...
Control unit System characteristics
message
F.464 Burner in a fault state
F.467 Burner in a fault state
132
(cont.)
Cause
Ionisation current too low
during calibration. Differ-
ence compared to previ-
ous value not plausible.
Gas supply insufficient
during calibration
Measures
Check ionisation electrode and
connecting cable. Check plug-in
connection for loose connections.
Check whether there is a lot of
dust in the ventilation air (e.g. from
construction work).
Check flue system or flue gas re-
circulation.
Check system for condensate
backup.
Note
To prevent water damage, detach
fan unit before removing the burn-
er.
Replace burner control unit if fault
is permanent.
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.
Test static gas pressure and gas
flow pressure.
Check on-site gas line and gas
flow switch for correct dimension-
ing.
Visually inspect gas train inlet and
strainer on the inlet side for con-
tamination.
Note
Contamination, e.g. from a brazed
gas line, may clog the inlet strainer
of the gas combination regulator.
Reset device.