Operating instructions

ManualsBrandsViessmann ManualsBoilerWS3A

Fault

code in

the dis-

play

Const. Weath.-

comp.

System char-

acteristics

Cause Remedy

CF X C ontrol mode Commun ica-

tion fault -

LON com-

munication

module

Replace the LON

communication

module

dA X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit A1

shorted out

Check the room

temperature sen-

sor – heating cir-

cuit A1

db X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit

M2 shorted

out

Check the room

temperature sen-

sor – heating cir-

cuit M2

dd X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit A1

lead broken

Check the room

temperature sen-

sor, heating ci r-

cuit A1 and t he

remote control

DIP switch setting

(see page 105)

dE X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit

M2 lead bro-

ken

Check the room

temperature sen-

sor, heating ci r-

cuit M2 and the

remote control

DIP switch setting

(see page 105)

E4 X X Burner

blocked

Fault – sup-

ply voltage

24 V

Replace control

unit

E5 X X Burner

blocked

Flame amp li-

fier fault

Replace the con-

trol unit.

Fault codes (cont.)

76

Troubleshooting

5692 619 GB