Viessmann VITOCONTROL-S, WB2B, Service Instructions Manual, Page: 77 / 124

77
Fault
code on
the dis-
play Const. weath.-
comp. System char-
acteristics Cause Measures
bA X Mixer M2 regu-
lates to 20
°
C
flow tempera-
ture
Communica-
tion fault
–
extension kit
for heating
circuit M2
Check extension
kit connections and
code. Start the
extension kit
bC X Control mode
without remote
control Communica-
tion fault
–
Vitotrol
remote con-
trol, heating
circuit A1
Check connec-
tions, cable, coding
address "A0" and
remote control DIP
switches (see
page 104)
bd X Control mode
without remote
control Communica-
tion fault,
Vitotrol
remote con-
trol, heating
circuit M2 Check connec-
tions, cable, coding
address "A0" and
remote control DIP
switches (see
page 104)
bE X Control mode Vitotrol
remote con-
trol incor-
rectly pro-
grammed Check remote con-
trol DIP switch set-
tings (see
page 104)
bF X Control mode Incorrect
LON commu-
nication mod-
ule Replace the LON
communication
module
C2 X X Control mode Communica-
tion fault,
solar control
unit Check connections
and coding
address "54"
C5 X X Control mode,
max. pump
speed Communica-
tion fault, var-
iable speed
circulation
pump in the
heating circuit
connection
set Check the setting
of coding address
"30"
Troubleshooting
Fault codes
(cont.)
5692 760 GB