Viessmann VITODENS 200-W Installation And Service Instructions Manual page 101

Fault messages
(cont.)
Displayed fault System characteristics
code
BB Mixer regulates to 20 °C flow
temperature.
BC Control mode without remote
control
BD Control mode without remote
control
BE Control mode without remote
control
BF Control mode
C1 Control mode
C2 Control mode
C3 Control mode
C4 Control mode
C5 Control mode, max. pump
speed
CD Control mode
CF Control mode
D3 Burner in a fault state or
blocked.
D4 Control mode
Burner is operating with a
limited modulation range.
Cause
Communication error, ex-
tension kit for heating cir-
cuit 3 (with mixer)
Communication error,
Vitotrol remote control,
heating circuit 1 (without
mixer)
Communication error,
Vitotrol remote control,
heating circuit 2 (with mix-
er)
Communication error,
Vitotrol remote control,
heating circuit 3 (with mix-
er)
Incorrect LON communi-
cation module
Communication error, EA1
extension
Communication error, so-
lar control module or
Vitosolic
Communication error,
AM1 extension
Communication error,
OpenTherm extension
Communication error, in-
ternal variable speed
pump
Communication error,
Vitocom 100 (KM-BUS)
Communication error,
communication module
Communication error, fan
unit
No air flow detected in fan
unit.
Troubleshooting
Measures
Check extension kit connections
and assignment.
Check connections, cable, param-
eter "A0" in the "Heating circuit"
group and remote control settings
(see page 151).
For wireless remote control units:
Check connection; place remote
control close to the boiler.
Check connections, cable, param-
eter "A0" in the "Heating circuit"
group and remote control settings
(see page 151).
For wireless remote control units:
Check connection; place remote
control close to the boiler.
Check connections, cable, param-
eter "A0" in the "Heating circuit"
group and remote control settings
(see page 151).
For wireless remote control units:
Check connection; place remote
control close to the boiler.
Replace LON communication mod-
ule.
Check connections.
Check solar control module or
Vitosolic.
Check connections.
Check OpenTherm extension.
Check setting of parameter "30" in
the "Boiler" group.
Check connections, Vitocom 100
and parameter "95" in the "Gener-
al" group.
Replace communication module.
Check the connecting cable to the
fan unit.
Press reset button R.
If the fault recurs, replace the fan
unit.
Check the mass flow sensor at the
fan unit. Check the flue system for
flue gas back pressure.
101