Operating instructions

ManualsBrandsViessmann ManualsBoilerType B2HA

121

Dis-

played

fault

code

Const. Weath.-

comp.

System char-

acteristics

Cause Measures

dC X Control mode

without room

influence

Short circuit,

room temper-

ature sensor,

heating circuit 3

(with mixer)

Check room tem-

perature sensor,

heating circuit 3

dd X Control mode

without room

influence

Lead break,

room temper-

ature sensor,

heating circuit 1

(without mix-

er)

Check room tem-

perature sensor,

heating circuit 1

and remote control

settings (see

page 156)

dE X Control mode

without room

influence

Lead break,

room temper-

ature sensor,

heating circuit 2

(with mixer)

Check room tem-

perature sensor,

heating circuit 2

and remote control

settings (see

page 156)

dF X Control mode

without room

influence

Lead break,

room temper-

ature sensor,

heating circuit 3

(with mixer)

Check room tem-

perature sensor,

heating circuit 3

and remote control

settings (see

page 156)

E0 X Control mode Fault, exter-

nal LON sub-

scriber

Check connections

and LON subscrib-

ers

Troubleshooting

Fault codes

(cont.)

5772 909 GB

Service