Viessmann VITOCROSSAL 200 Service Instructions Manual page 58

Troubleshooting
Fault codes
(cont.)
Displayed System characteris-
fault code tics
F 80 Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
F 81 Burner control unit in
a fault state
F 82 Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
F 83 Burner control unit in
a fault state
F 88 Burner control unit in
a fault state
F 89 Burner control unit in
a fault state
F b7 Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
58
Cause
Short circuit, boiler
water temperature
sensor, burner
control unit
Sensor drift, boiler
water temperature
sensor, burner
control unit
Short circuit, flue
gas temperature
sensor (A or B),
burner control unit
Sensor drift, flue
gas temperature
sensor (A or B),
burner control unit
Lead break, boiler
water temperature
sensor, burner
control unit
Lead break, flue
gas temperature
sensor (A or B),
burner control unit
Coding card not in-
serted in the burner
control unit; incor-
rect or faulty cod-
ing card
Measures
Check lead and dual sen-
sor; replace sensor if re-
quired
Check lead and dual sen-
sor; replace sensor if re-
quired
Check lead and sensors
(A and B), replace sensor
if required
Check lead and sensors
(A and B), replace sensor
if required
Check lead and dual sen-
sor; replace sensor if re-
quired
Check lead and sensors
(A and B), replace sensor
if required
Insert coding card; check
coding card; replace if re-
quired