Viessmann Vitocrossal 300 Series Service Instructions Manual page 88

Troubleshooting
Fault Codes
(continued)
Fault code on display
BD
BE
BF
C1
C2
C4
C7
C8
CD
NOT USED
CF
D6
D7
*1 Control mode:..............Boiler/burner fully operational (fault code must be verified and reset).
Burner in fault mode:.....Boiler control requires manual reset before burner can resume operation.
Burner blocked: ...........If fault cause is corrected, burner resumes operation.
88
System behavior*1
Control mode without remote
control
Control mode without remote
control
Control mode
Control mode
Control mode
Control mode
Control mode, max. pump speed Communication
Control mode, max. pump
speed
Control mode
Control mode
Control mode
Control mode
Vitocrossal 300 CU3A 26 to 199 Service
Cause
Communication error,
remote control Vitotrol
heating circuit 2
(with mixing valve)
Communication error,
remote control Vitotrol
heating circuit 3
(with mixing valve)
Incorrect LON
communication module
Communication fault
extension EA1
Communication fault -
solar control unit or
Vitosolic
Communication fault,
Open Therm extension
fault-variable
speed circulation
pump,heating circuit
without mixing valve,
heating circuit pump A1
Communication error,
external variable speed
heating circuit pump,
heating circuit 3 (with
mixing valve)
Communication fault,
Vitocom 100 (KM-BUS)
Communication fault -
LON communication
module
Input DE1 reports a
fault at extension EA1
Input DE2 reports a
fault at extension EA1
Corrective action
Check connections, cable,
coding address "A0" in "Heating
circuit" group and remote control
unit setting. For wireless remote
control units: Check radio path
connections, place
remote control unit and wireless
repeater close to the boiler.
Check KM BUS connection to
wireless base station. Replace
wireless components.
Check connections, cable,
coding address "A0" in "Heating
circuit" group and remote control
unit setting. For wireless remote
control units: Check radio path
connections, place
remote control unit and wireless
repeater close to the boiler.
Check KM BUS connection to
wireless base station. Replace
wireless components.
Replace LON communication
module.
Check connections.
Without extension EA1, set
code "35:0"
Check solar control or Vitosolic.
Check Open Therm extension.
Check setting of coding address
"E5".
Check setting of coding address
"E5"
Check connections Vitocom 100
coding address "95"
Replace LON communication
module.
Remove fault at appliance
concerned.
Remove fault at appliance
concerned.