Viessmann Vitodens 200-W Installation Instructions Manual page 122

Troubleshooting
Fault codes
(cont.)
Dis- Const.
played
fault
code
bb
bC
122
Weath.- System char-
comp. acteristics
X Mixer regulates
to 20 °C flow
temperature.
X Control mode
without remote
control
Cause Measures
Communica- Check extension
tion error, ex- kit connections and
tension kit for code.
heating circuit
3 (with mixer)
Communica- Check connec-
tion error, tions, cable, coding
Vitotrol re- address "A0" in
mote control, "Heating circuit"
heating circuit group and remote
1 (without control settings
mixer) (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.