Viessmann VITODENS 333-F WS3A Service Instructions Manual page 77

Fault codes
(cont.)
Fault Const. Weath.-
code comp.
on the
display
b8 X X
bA X
bC X
bd X
bE X
bF X
C2 X X
System char- Cause
acteristics
Burner Flue gas
blocked temperature
sensor lead
broken
Mixer M2 reg- Communica-
ulates to a tion fault, ex-
flow tempera- tension kit
ture of 20 °C. for heating
circuit M2
Control mode Communica-
without remote tion fault,
control Vitotrol re-
mote control,
heating cir-
cuit A1
Control mode Communica-
without remote tion fault,
control Vitotrol re-
mote control,
heating cir-
cuit M2
Control mode Vitotrol re-
mote control
incorrectly
programmed
Control mode Incorrect
LON com-
munication
module
Control mode KM BUS
lead broken
to solar heat-
ing control
unit
Troubleshooting
Measures
Check the flue
gas temperature
sensor
Check the exten-
sion kit connec-
tions and coding.
Start the exten-
sion kit.
Check connec-
tions, cable/lead
and coding ad-
dress "A0"
Check connec-
tions, cable/lead
and coding ad-
dress "A0"
Check remote
control DIP switch
setting (see
page 105)
Replace the LON
communication
module
Check the KM
BUS cable, the
solar control unit
and coding ad-
dress "54"
77