Viessmann VITODENS 300 WB3A, Service Instructions Manual

Page: 95 / 148

Displayed
fault code Const. Weat-
her-
comp. System
character-
istics Cause Remedy
bA X Mixer M2
continues
to regulate Communication
fault - extension kit
for mixer circuit M2 Check the
extension kit
connections
and coding.
Start the
extension kit.
bC X Control
mode with-
out remote
control Communication
fault - Vitotrol
remote control
heating circuit A1 Check con-
nections,
cable, coding
address A0
and the
remote con-
trol DIP
switches
bd X Control
mode with-
out remote
control Communication
fault - Vitotrol
remote control
heating circuit M2
bE X Control
mode Vitotrol remote
control incorrectly
encoded Check the
DIP switch
settings of
the remote
control
bF X Control
mode Incorrect LON com-
munication module Replace the
LON commu-
nication mod-
ule
C2 X X Control
mode Communication
fault - solar control
unit Check con-
nections and
coding
address 54
C5 X X Control
mode,
max. pump
speed Communication
fault - variable
speed internal
pump Check coding
address 30
settings;
check the
heating cir-
cuit pump
DIP switch
settings
Checking and acknowledging faults
(cont.)
79
Troubleshooting
56
92
550
GB