40
Troubleshooting
Faults which are displayed at the programming unit
(cont.)
Fault
code
System
characteristics
Cause
Remedy
bCc
Control mode
without remote
control
Communication fault
Vitotrol remote
control,
heating circuit A1
Check connections,
cable and coding
address A0
bCd
Communication fault
Vitotrol remote
control,
mixer circuit M2
Check connections,
cable and coding
address A0
be
Control mode
Vitotrol remote
control incorrectly
encoded
Check remote
control DIP switch
setting (see pages68
and 70)
c2
Lead broken
KM BUS to the solar
control unit
Check KM BUS cable
and solar control unit.
Without solar
control unit:
Set code 54:0
c4
Communication fault
Function extension
0−10V
Check connections
and cables/leads. If
required, replace the
function extension.
Without function
extension:
Set code 9d:0
c5
Control mode, max.
pump speed
Communication fault
Variable speed
heating circuit pump,
heating circuit A1
Check coding
address E5 and
heating circuit pump
DIP switch settings
c6
Communication fault
Variable speed
heating circuit pump,
mixer circuit M2
g
5862700GB