Operating instructions

Fault
code
on the
display
Const. weath.-
comp.
System char-
acteristics
Cause Measures
C2 X X Control mode Communica-
tion fault,
solar control
unit
Check connec-
tions and coding
address "54".
C6 X Control mode,
max. pump
speed
Communica-
tion fault –
external vari-
able speed
heating cir-
cuit pump,
heating cir-
cuit with
mixer M2
Check setting of
coding address
"E5"
C7 X X Control mode,
max. pump
speed
Communica-
tion fault –
external vari-
able speed
heating cir-
cuit pump,
heating
circuit A1
Check setting of
coding address
"E5"
Cd X X Control mode Communica-
tion fault
Vitocom 100
(KM BUS)
Check connec-
tions, Vitocom 100
and coding ad-
dress "95".
CE X X Control mode Communica-
tion fault –
ext. exten-
sion
Check connec-
tions and coding
address "2E".
CF X Control mode Communica-
tion fault,
LON com-
munication
module
Replace the LON
communication
module.
dA X Control mode
without room
influence
Room tem-
perature
sensor, heat-
ing circuit A1
shorted out
Check the room
temperature sen-
sor, heating cir-
cuit A1.
Fault codes (cont.)
74
Troubleshooting
5692 672 GB