Viessmann Vitodens 300 Service Instructions Manual page 79

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