Viessmann Vitodens 333 Service Instructions Manual page 77

Checking and acknowledging faults
Display Const.
fault code
9C X
9F X
A7
b0 X
b8 X
b1 X
b4 X
b5 X
b7 X
bA
Weat- System
h. character-
comp. istics
X
X Control
mode
X Control
mode
X Burner
blocked
X
X Control
mode
X Emissions
test mode
X Control
mode
X Burner
blocked
X Mixer M2
continues
to regulate
Troubleshooting
(cont.)
Cause Remedy
Cylinder tempera-
ture sensor lead
break
Solar control unit See solar
fault message control unit
service in-
structions
Faulty program- Replace pro-
ming unit gramming
unit
Flue gas tempera- Check flue
ture sensor shorted gas tempera-
out ture sensor
(see page 87)
Flue gas temp.
sensor lead break
Communication Check con-
fault – program-
nections and
ming unit (internal) replace pro-
gramming
unit, if neces-
sary
Internal fault ana- Replace con-
log converter trol unit
Internal fault Replace con-
trol unit
Boiler coding card Plug in boiler
missing, faulty or coding card
incorrect card in- or replace, if
serted faulty
Communication Check exten-
fault – extension kit
sion kit con-
for mixer circuit M2 nections and
coding. Start
extension kit.
77