Viessmann VITODENS 300 Service Instructions Manual page 76

Troubleshooting
Fault codes
(cont.)
Display Const. Weath.-
fault comp.
code
92 X X
9A X X
93 X X
9B X X
94 X X
9C X X
9F X X
A7 X
b0 X X
b8 X X
76
System char- Cause
acteristics
Control mode Solar: Col-
lector tem-
perature
sensor
shorted out
Control mode Solar: Col-
lector tem-
perature
sensor lead
broken
Control mode Solar: Sen-
sor S 3
shorted out
Control mode Solar: Sen-
sor S 3 lead
broken
Control mode Solar: Cylin-
der tempera-
ture sensor
shorted out
Control mode Cylinder
temperature
sensor lead
broken
Control mode Solar control
unit fault
message
Control mode Faulty pro-
gramming
unit.
Burner Flue gas
blocked temperature
sensor
shorted out
Burner Flue gas
blocked temperature
sensor break
Remedy
Check sensor.
Check sensor.
Check sensor.
Check sensor.
Check sensor.
Check sensor.
See solar control
unit service in-
structions.
Replace program-
ming unit.
Check the flue
gas temperature
sensor (see page
87).
Check the flue
gas temperature
sensor (see page
87).