122
Dis-
played
fault
code
Const.
Weath.-
comp.
System char-
acteristics
Cause
Measures
bb
X
Mixer regulates
to 20 °C flow
temperature.
Communica-
tion error, ex-
tension kit for
heating circuit
3 (with mixer)
Check extension
kit connections and
code.
bC
X
Control mode
without remote
control
Communica-
tion error,
Vitotrol re-
mote control,
heating circuit
1 (without
mixer)
Check connec-
tions, cable, coding
address "A0" in
"Heating circuit"
group and remote
control settings
(see page 160).
For wireless re-
mote controls:
Check radio path
connections, place
wireless remote
control and wire-
less repeater close
to the boiler. Check
KM BUS connec-
tion to wireless
base station. Re-
place the wireless
components.
Troubleshooting
Fault codes
(cont.)
5585 174 GB