Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors page 124

Troubleshooting
Fault messages on the gas condensing...
Control unit System characteristics
message
F.369 Burner in a fault state
F.370 Burner in a fault state
F.371 Burner in a fault state
F.372 Burner in a fault state
F.373 Burner in a fault state
124
(cont.)
Cause
Flame is lost immediately
after flame formation (dur-
ing safety time).
Fuel valve or modulation
valve will not close.
Fan speed too low
Repeated flame loss dur-
ing calibration
Heat transfer too low dur-
ing calibration
Temperature limiter has
shut down.
Measures
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode:
Distance to burner gauze assem-
■
bly (see page 79)
Contamination of electrode
■
Reset device.
Check the gas train, replace if nec-
essary.
Reset device.
Check fan.
Check connection cables on fan.
Check power supply on fan.
Reset device.
Check ionisation electrode and
connecting cable. Check plug-in
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.
Ensure adequate heat transfer.
Check circulation pump for faults,
calcification or blockage.
Reset device.