Viessmann VITOLIGNO 300-C Installation And Service Instructions Manual page 131

Fault codes
(cont.)
Fault code dis- System characteristics
played
8C Burner blocked
8F Burner blocked
90 Burner blocked
91 Burner blocked
93 Burner blocked
A3 Burner blocked
Fault code A3: Not for boilers
with 8 to 48 kW
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 op-
eration.
Fault, light barrier, firebed
monitoring
Fault rectification
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
Recalibrate Lambda probe.
■
Acknowledge with
d
■
Recalibrate the Lambda probe af-
ter replacing.
Note
Information regarding "Checking
the Lambda probe" and "Calibrat-
ing the Lambda probe" in chapter
"Maintenance".
Clean the Lambda probe.
Recalibrate Lambda probe.
■
Acknowledge with
d
■
Recalibrate the Lambda probe af-
ter replacing.
Note
Information regarding "Checking
the Lambda probe" and "Calibrat-
ing the Lambda probe" in chapter
"Maintenance".
Top up material in day hopper if
necessary.
Check installation of ash box.
Clean light barrier and sight glass.
131