Viessmann Vitoplus 300, Service Instructions Manual

Page: 70 / 120

Display fault
code System char-
acteristics Cause Measures
9F Control mode Solar control unit fault
message See solar control
unit service in-
structions
A7 Control mode
as per the de-
livered condi-
tion Faulty programming unit Replace program-
ming unit
b0 Burner
blocked Flue gas temperature
sensor shorted out Check the flue
gas temperature
sensor (see
page 79)
b8 Flue gas temperature
sensor break
b1 Control mode
as per the de-
livered condi-
tion Communication error pro-
gramming unit (internal) Check connec-
tions and replace
programming unit,
if required
b4 Regulates as if
the outside
temperature
was 0 °C Internal fault analog con-
verter Replace the con-
trol unit
b5 Control mode
as per the de-
livered condi-
tion Internal fault Replace the con-
trol unit
b7 Burner
blocked Boiler coding card miss-
ing, faulty or incorrect
boiler coding card Plug in boiler cod-
ing card or re-
place, if faulty
bA Mixer M2 regu-
lates in accor-
dance with the
last trans-
mitted set
value Communication fault –
extension kit for heating
circuit with mixer M2
Check the exten-
sion kit connec-
tions and coding.
Start the exten-
sion kit.
bC Control mode
without remote
control Communication fault –
Vitotrol remote control,
heating circuit A1
Check connec-
tions, cable, cod-
ing address "A0"
and the remote
control DIP
switches
Fault codes
(cont.)
70
Troubleshooting
5692
536
GB