Viessmann VITOLIGNO 300-C Installation And Service Instructions Manual page 100

Troubleshooting
Fault Display
Fault codes
Fault code displayed
8C
8F
90
91
93
A4
A5
100
(continued)
System characteristics
Burner blocked
Burner blocked
Burner blocked
Burner blocked
Burner blocked
Burner blocked
Burner blocked
Vitoligno 300-C Installation/Service
Cause
Return temperature not
reached during operation.
Oxygen content in flue
gas too low during load
operation.
Lambda probe inaccurate
Lambda probe heavily soiled

Lambda probe faulty

Electronics fault

Residual O flue gas value
2
is too high during load
operation.
Fault, material shortage
Measures
Check return temperature
sensor. Check the plug for
the mixing valve motor of
the return temperature
raising facility is inserted
correctly (see installation and
service instructions for return
temperature raising facility).
Check Lambda probe.
Cleaning the combustion
chamber, Lambda probe
and sensor well of the flue
gas temperature sensor
Recalibrate Lambda probe

Acknowledge with d

Recalibrate the Lambda
probe after replacing.
Clean Lambda probe
Recalibrate Lambda probe

Acknowledge with d

Recalibrate the Lambda
probe after replacing.
Top up the day hopper if
necessary.
Check fuel store fill level

pellet supply with vacuum

system: Check the output
stage of the vacuum
module. If necessary,
select a higher power stage
(see chapter "Setting the
vacuum module").
Adjust the vacuum module
blocking time in the control
unit.