Viessmann VITOLIGNO 300-P Service Instructions Manual page 91

Fault display
(cont.)
Displayed System characteris-
fault code tics
9F Control mode
A7 Control mode as per
delivered condition
AA Control mode
B1 Control mode
B4 Regulates as if the
outside temperature
were 0 °C
B5 Control mode
B6 Burner blocked
B7 Emergency mode
B9 Burner blocked
BA Mixer M1 continues
to regulate
BB Mixer M2 continues
to regulate
BC Control mode without
remote control
Cause
Solar control unit
fault; displayed if a
fault without fault
code occurs at the
solar control unit
Programming unit
faulty
Configuration fault
Communication
error, program-
ming unit
Internal PCB fault
Internal PCB fault
Incorrect boiler
coding card
Boiler coding card
missing or faulty
Incorrect transmis-
sion of the boiler
coding card details
Communication
error, extension kit
for heating circuit
with mixer M1
Communication
error, extension kit
for heating circuit
with mixer M2
Communication
error, Vitotrol
remote control,
heating circuit 1
Troubleshooting
Measures
Check solar control unit
Separate installa-
tion and service
instructions
Replace programming
unit
Check code configuration
Check connections and
replace programming unit
if required
Replace the control unit
Replace the control unit
Insert the correct boiler
coding card
Insert boiler coding card
or replace if faulty
Replace boiler coding
card; replace PCBs in
control unit if required
Check extension kit con-
nections and code. Start
the extension kit.
Check extension kit con-
nections and code. Start
the extension kit.
Check connections,
cable, coding address
"A0" and remote control
DIP switch (see
pages 107 and 108)
91