Viessmann Vitovalor PT2 E11T Installation And Service Instructions Manual page 124

Troubleshooting
Fault messages for gas condensing module
Fault number System characteristics
on the display
F.467 Burner in a fault state
F.468 Burner in a fault state
F.469 Burner in a fault state
F.471 No heat demand
F.472 Control mode without elec-
tricity meter data
F.473 No heat demand
F.474 Burner in a fault state
F.475
124
(cont.)
Cause
Gas supply insufficient
during calibration
Ionisation current too high
during calibration
Heat transfer too low dur-
ing calibration
Temperature limiter has
shut down.
No water pressure sensor
signal
Communication error,
electricity meter
Communication error,
HMU control unit
Error in scheduled pro-
gram run monitoring
Fuel cell fault
Measures
Test static gas pressure and gas
flow pressure.
Check that on-site gas line and gas
flow switch are correctly sized.
Visually inspect gas train inlet and
strainer on the inlet side for con-
tamination.
Note
Contamination from a brazed gas
line, for example, can block up the
gas train strainer on the inlet side.
Reset burner.
Check gap between ionisation
electrode and burner gauze as-
sembly (see page 72).
Check whether there is a lot of
dust in the ventilation air (e.g. from
construction work).
Note
Deposits on the electrodes indicate
foreign bodies in the ventilation 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 burner.
Ensure adequate heat transfer.
Reset burner.
Check the water pressure sensor.
Check connecting cable to the M-
bus meter.
Check connecting cable between
burner control unit and HMU con-
trol unit.
Check ignition electrodes and con-
necting cables.
Check ionisation electrode and
connecting cable.
Reset burner.
Notify Viessmann Technical Serv-
ices.