Viessmann VITODENS 300 Service Instructions Manual page 78

Troubleshooting
Fault codes
(cont.)
Display Const. Weath.-
fault comp.
code
bF X
C2 X X
C5 X X
C6 X
C7 X X
Cd X X
78
System char- Cause
acteristics
Control mode Incorrect
LON com-
munication
module
Control mode Communica-
tion fault -
solar control
unit
Control mode, Communica-
max. pump tion error
speed variable
speed inter-
nal pump
Control mode, Communica-
max. pump tion fault -
speed variable
speed circu-
lation pump,
heating
circuit M2
Control mode, Communica-
max. pump tion fault -
speed external vari-
able speed
circulation
pump, heat-
ing circuit A1
Control mode Communica-
tion fault
Vitocom 100
(KM BUS)
Remedy
Replace the LON
communication
module.
Check connec-
tions and coding
address "54".
Check coding ad-
dress "30" set-
tings; check the
DIP switch set-
tings in the pump
wiring box:
Switch 1: OFF
(delivered condi-
tion)
Switch 2: OFF
(delivered condi-
tion)
Check coding ad-
dress "E5" set-
tings; check the
DIP switch set-
tings in the pump
wiring box:
Switch 1: OFF
Switch 2: ON
Check coding ad-
dress "E5" set-
tings; check the
DIP switch set-
tings in the pump
wiring box:
Switch 1: ON
Switch 2: OFF
Check connec-
tions and the
Vitocom 100.