Viessmann Vitoligno 300-C Installation And Service Instructions For Contractors page 72

Troubleshooting
Fault display
(cont.)
Fault code dis- System characteristics
played
66 No solar yield
67 No solar yield
68 No control mode at heating
circuit 4 (KM BUS)
8C Burner blocked
8F Burner blocked
90 Burner blocked
91 Burner blocked
93 Burner blocked
A4 Burner blocked
A5 Burner blocked
A6 Burner blocked
AA Burner blocked
AB Burner blocked
AC Burner blocked
B4 Control mode
BD Burner blocked
BE Burner blocked
C8 Burner blocked
72
Cause
Lead break, collector tem-
perature sensor
Lead break, solar refer-
ence sensor
Lead break, flow tempera-
ture sensor
Return temperature not
reached during operation.
Oxygen content in flue
gas too low during load
operation.
Fuel too damp
■
Lambda probe inaccu-
■
rate
Lambda probe heavily
■
soiled
Lambda probe faulty
■
Electronics fault
■
Residual O flue gas value
2
is too high during load op-
eration.
Fault, material shortage
Fault, material shortage
due to time-out: The
blocking time set for the
vacuum module is too
long.
Ash box full
Boiler had excess temper-
ature.
Water pressure is too low.
Water pressure is too
high.
Fuel store empty
Maintenance cover/door
of fuel store open
Discharge transfer conta-
minated
Changeover unit has not
reached position.
Measures
Check collector temperature sen-
sor.
Check solar reference sensor.
Check flow temperature sensor.
Check return temperature sensor.
Check Lambda probe.
Use suitable dry fuel
■
Recalibrate Lambda probe
■
Acknowledge with
d
■
Clean Lambda probe
■
Recalibrate Lambda probe
■
Acknowledge with
d
■
–
Check fuel store fill level
■
For 8 and 12 kW - manual charg-
■
ing: Check day hopper fill level.
For 18 to 48 kW - pellet supply
■
via vacuum system: Check vac-
uum module output stage. If nec-
essary, select a higher output
stage (see chapter "Setting the
vacuum module").
Adjust the vacuum module block-
ing time in the control unit.
Emptying the ash boxes
■
Acknowledge fault
■
Check set values in control unit
■
Check pump
■
Check valves
■
Checking sensors
■
Check water pressure.
Check water pressure.
Check fuel store fill level.
Check maintenance cover/door of
fuel store.
Clean proximity switch.
Check changeover unit.