Viessmann Vitodens 333-F Service Instructions Manual page 82

Troubleshooting
Fault codes
(cont.)
Fault Const. weath.-
code comp.
on the
display
C7 X X
Cd X X
CE X X
CF X
dA X
db X
82
System char- Cause
acteristics
Control mode, Communica-
tion fault –
max. pump
speed external vari-
able speed
heating cir-
cuit pump,
heating
circuit A1
Control mode Communica-
tion fault
Vitocom 100
(KM BUS)
Control mode Communica-
tion fault –
ext. exten-
sion
Control mode Communica-
tion fault,
LON com-
munication
module
Control mode Room tem-
without room perature
influence sensor, heat-
ing circuit A1
shorted out
Control mode Room tem-
without room perature
influence sensor, heat-
ing circuit
with mixer
M2 shorted
out
Measures
Check setting of
coding address
"E5"
Check connec-
tions, Vitocom 100
and coding ad-
dress "95"
Check connec-
tions and coding
address "2E"
Replace the LON
communication
module
Check the room
temperature sen-
sor, heating cir-
cuit A1
Check the room
temperature sen-
sor, heating cir-
cuit with mixer M2