Viessmann Vitodens 100 Series Installation And Service Instructions Manual page 69

Fault display
(cont.)
Displayed System character-
fault code istics
F78 Function at the ex-
ternal extension faul-
ty
F80 Function at the ex-
ternal extension faul-
ty
F88 Function at the ex-
ternal extension faul-
ty
F90 Function at the ex-
ternal extension faul-
ty
F98 Function at the ex-
ternal extension faul-
ty
Fb0 Burner locked out
Cause
Lead break, col-
lector temperature
sensor S1 at the
external extension
Short circuit, lower
cylinder tempera-
ture sensor S2 at
the external exten-
sion
Lead break, lower
cylinder tempera-
ture sensor S2 at
the external exten-
sion
Short circuit, upper
cylinder tempera-
ture sensor S3 at
the external exten-
sion
Lead break, upper
cylinder tempera-
ture sensor S3 at
the external exten-
sion
Short circuit, flue
gas temperature
sensor
Troubleshooting
Measures
Checking the sensor
Installation and
service instruc-
tions for external
extension
Checking the sensor
Installation and
service instruc-
tions for external
extension
Checking the sensor
Installation and
service instruc-
tions for external
extension
Checking the sensor
Installation and
service instruc-
tions for external
extension
Checking the sensor
Installation and
service instruc-
tions for external
extension
Check flue gas tempera-
ture sensor (see
page 77).
69