Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors page 126

Troubleshooting
Fault messages on the gas condensing...
Control unit System characteristics
message
F.377 Burner in a fault state
F.378 Burner in a fault state
126
(cont.)
Cause
Post-processing of ionisa-
tion adjustment: Stabilisa-
tion conditions for post-
calibration not met
Flame loss in the stabilisa-
tion or operating phase
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.
Check gas supply (gas pressure
■
and gas flow switch).
Check gas train.
■
Check if condensate banked.
■
Note
To prevent water damage, de-
tach fan unit before removing the
burner.
Check ionisation electrode and
■
connecting cable.
Check ignition:
Connecting cables to ignition
■
module and ignition electrode
Ignition electrode clearance and
■
contamination: See page 79.
Check ignition electrode for bro-
■
ken ceramic.
Reset device.