Operating instructions

58
Message
System characteristics Cause Measures
BA KM BUS mixer HC
Communication fault,
KM BUS or internal fault
in extension set for one
heating circuit with mixer
Check extension kit con-
nections and code.
BB KM BUS mixer cooling
KM BUS communication
error or internal fault in
extension kit, NC-Box for
cooling circuit
Check connections and
parameter settings.
BC KM BUS R/C HC1
Communication error -
KM BUS remote control;
heating circuit without
mixer A1
Check remote control
connections and code;
switch ON remote con-
trol.
BD KM BUS R/C HC2
Communication error -
KM BUS remote control;
heating circuit with mixer
M2
Check remote control
connections and code;
switch ON remote con-
trol.
BF Communication module
LON communication
error; incorrect LON
communication module
Check connections and
type of LON communica-
tion module.
If required, replace in the
following order: Cross
connect PCB, ribbon
cables between the cross
connect PCB and the
main PCB
C5 Power-OFF
Power-OFF enabled
(triggered by power sup-
ply utility)
No measures required.
If message persists:
Check the connection at
the controller and sensor
PCB first at terminal X3.7
(feed) then at terminal
X3.6 (230 V~).
Troubleshooting
Messages
(cont.)
5441 603 GB