Operating instructions

ManualsBrandsViessmann ManualsBoilerWB2B

Fault

code

on the

display

Const. weath.-

comp.

System char-

acteristics

Cause Measures

db X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit

with mixer

M2 shorted

out

Check the room

temperature sen-

sor, heating cir-

cuit with mixer

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 cir-

cuit A1 and the

remote control

DIP switch set-

tings (see

page 104).

dE X Control mode

without room

influence

Room tem-

perature

sensor, heat-

ing circuit

with mixer

M2 lead bro-

ken

Check the room

temperature sen-

sor, heating cir-

cuit with mixer M2

and the remote

control DIP switch

settings (see

page 104).

E4 X X Burner

blocked

Fault, supply

voltage 24 V

Replace the con-

trol unit.

E5 X X Burner

blocked

Fault – flame

amplifier

Replace the con-

trol unit.

E8 X X Burner in a

fault state

The ionisa-

tion current

lies outside

the permissi-

ble range

Check the ionisa-

tion electrode and

cable.

Press "E

RESET".

Fault codes (cont.)

75

Troubleshooting

5692 672 GB