Viessmann Vitoligno 300-H Installation And Service Instructions For Contractors page 122

Troubleshooting
Fault codes
(cont.)
Displayed fault System characteristics
code
8C Burner locked out
8F Burner locked out
90 Burner locked out
91 Burner locked out
93 Burner locked out
9A Burner locked out
9B Flue gas filter not working
9C Flue gas filter not working
9D Flue gas filter not working
122
Cause
Return temperature is not
reached during operation
Oxygen content in flue
gas too low during load
operation
Lambda probe inaccurate
Lambda probe heavily
■
soiled
Lambda probe faulty
■
PCB fault
■
Residual O flue gas value
2
is too high during load op-
eration
The door contact of the
flue gas filter has been in-
terrupted
No feedback from the high
voltage module
The breakdown voltage at
the flue gas filter is too
high
The flue gas filter is dirty
The temperature in the
high voltage module of the
flue gas filter is too high
No CAN connection to the
flue gas filter
Measures
Check return temperature sensor
Check mixer motor of return tem-
perature raising facility
Installation and service in-
structions, return tempera-
ture raising facility
Check Lambda probe
Clean the combustion chamber,
Lambda probe and sensor well of
the flue gas temperature sensor
Acknowledge fault with
■
Check Lambda probe
■
Recalibrate Lambda probe
■
Replace and calibrate Lambda
■
probe if necessary
See chapter "Maintenance"
Acknowledge fault with
■
Cleaning Lambda probe
■
Check Lambda probe
■
Recalibrate Lambda probe
■
Replace and recalibrate Lambda
probe if necessary
See chapter "Maintenance"
Top up the day hopper if necessary
Check installation of ash box
Close the flue gas filter door
Clean the flue gas filter
■
Manufacturer's installation
and service instructions
If the fault recurs, notify your
■
heating contractor
Check the ambient temperature
■
of the high voltage module
Manufacturer's installation
and service instructions
If the fault recurs, notify your
■
heating contractor
Check wiring
■
Manufacturer's installation
and service instructions
If the fault recurs, notify your
■
heating contractor
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