Operating instructions

ManualsBrandsViessmann ManualsBoilerWS3A

Fault

code in

the dis-

play

Const. Weath.-

comp.

System char-

acteristics

Cause Remedy

C2 X X Control mode Communica-

tion fault -

solar control

unit

Check the con-

nections and set-

tings of coding

address "54"

C5 X X Control mode,

max. pump

speed

Communica-

tion error –

variable

speed inter-

nal pump

Check the coding

address "30" set-

tings; check the

DIP switch set-

tings in the pump

wiring chamber:

Switch 1: OFF,

Switch 2: ON

C6 X Control mode,

max. pump

speed

Communica-

tion fault -

external vari-

able speed

heating cir-

cuit pump,

heating

circuit M2

Check the coding

address "E5" set-

tings; check the

DIP switch set-

tings in the pump

wiring chamber:

Switch 1: OFF,

Switch 2: ON

C7 X X Control mode,

max. pump

speed

Communica-

tion fault -

external vari-

able speed

heating cir-

cuit pump,

heating

circuit A1

Check the coding

address "E5" set-

tings; check the

DIP switch set-

tings in the pump

wiring chamber:

Switch 1: ON,

Switch 2: OFF

Cd X X Control mode Communica-

tion fault

Vito com 100

(KM BUS)

Check connec-

tions, Vitocom 100

and coding ad-

dress "95"

CE X X Control mode Communica-

tion fault –

ext. exten-

sion

Check connec-

tions and coding

address "2E"

Fault codes (cont.)

75

Troubleshooting

5692 619 GB