Viessmann FS2B, Installation And Service Instructions Manual

Page: 107 / 164

107
Dis-
played
fault
code Const. Weath.-
comp. System char-
acteristics Cause Measures
bb X Mixer regulates
to a flow tem-
perature of
20 °C Communica-
tion error,
extension kit
for heating
circuit 3 (with
mixer) Check extension
kit connections and
code
bC X Control mode
without remote
control Communica-
tion error,
remote con-
trol Vitotrol
heating circuit
1 (without
mixer) Check connec-
tions, lead, coding
address "A0" and
remote control set-
tings (see
page 144)
bd X Control mode
without remote
control Communica-
tion error,
remote con-
trol Vitotrol
heating circuit
2 (with mixer) Check connec-
tions, lead, coding
address "A0" and
remote control set-
tings (see
page 144)
bE X Control mode
without remote
control Communica-
tion error,
remote con-
trol Vitotrol
heating circuit
3 (with mixer) Check connec-
tions, lead, coding
address "A0" and
remote control set-
tings (see
page 144)
bF X Control mode Incorrect
LON commu-
nication mod-
ule Replace the LON
communication
module
C1 X X Control mode Communica-
tion error
extension
EA1 Check electrical
connections
C3 X X Control mode Extension
AM1 commu-
nication error Check electrical
connections
Troubleshooting
Fault codes
(cont.)
5457 552 GB
Service