Operating instructions

ManualsBrandsViessmann ManualsBoilerWS3A

Fault code

in the dis-

play

Const. Weat-

h.

comp.

System

character-

istics

Cause Remedy

9C X X Cylinder tempera-

ture sensor lead

break

9F X X Control

mode

Solar control un it

error message

See solar

control unit

service

instructions

A7 X Control

mode

Faulty operating

interface

Replace

operating

interface

b0 X X Burner

blocked

Flue gas tempera-

ture sensor shor t

circuit

Check the

flue gas tem-

perature sen-

sor (see

page 87)

b8 X X Flue gas tempera-

ture sensor brea k

b1 X X Control

mode

Communication

fault – program-

ming unit ( internal)

Check con-

nections and

replace the

programming

unit, if neces-

sary

b4 X X Emissions

test mode

Internal error ana-

log converter

Replace con-

trol unit

b5 X X Control

mode

Internal error Replace con-

trol unit

b7 X X Burner

blocked

Boiler coding card

missing, faulty or

incorrect card

inserted

Plug in the

boiler coding

card or

replace, if

faulty

bA X Mixer M2

continues

to move

Communication

fault - extension kit

for mixer circui t M2

Check the

extension kit

connections

and coding.

Start the

extension kit.

Checking and acknowledging faults (cont.)

77

Troubleshooting

5692 548 GB