125
Dis-
played
fault
code
Const.
Weath.-
comp.
System char-
acteristics
Cause
Measures
bd
X
Control mode
without remote
control
Communica-
tion error, re-
mote control
Vitotrol heat-
ing circuit 2
(with mixer)
Check connec-
tions, cable, coding
address "A0" in
"Heating circuit"
group and remote
control unit setting.
For wireless re-
mote control units:
Check radio path
connections, place
remote control unit
and wireless re-
peater close to the
boiler. Check KM
BUS connection to
wireless base sta-
tion. Replace wire-
less components.
bE
X
Control mode
without remote
control
Communica-
tion error, re-
mote control
Vitotrol heat-
ing circuit 3
(with mixer)
Check connec-
tions, cable, coding
address "A0" in
"Heating circuit"
group and remote
control unit setting.
For wireless re-
mote control units:
Check radio path
connections, place
remote control unit
and wireless re-
peater close to the
boiler. Check KM
BUS connection to
wireless base sta-
tion. Replace wire-
less components.
Troubleshooting
Fault codes
(cont.)
5623 520 GB
Service
