58
Displayed
fault code
System characteris-
tics
Cause
Measures
F 80
Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
Short circuit, boiler
water temperature
sensor, burner
control unit
Check lead and dual sen-
sor; replace sensor if re-
quired
F 81
Burner control unit in
a fault state
Sensor drift, boiler
water temperature
sensor, burner
control unit
Check lead and dual sen-
sor; replace sensor if re-
quired
F 82
Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
Short circuit, flue
gas temperature
sensor (A or B),
burner control unit
Check lead and sensors
(A and B), replace sensor
if required
F 83
Burner control unit in
a fault state
Sensor drift, flue
gas temperature
sensor (A or B),
burner control unit
Check lead and sensors
(A and B), replace sensor
if required
F 88
Burner control unit in
a fault state
Lead break, boiler
water temperature
sensor, burner
control unit
Check lead and dual sen-
sor; replace sensor if re-
quired
F 89
Burner control unit in
a fault state
Lead break, flue
gas temperature
sensor (A or B),
burner control unit
Check lead and sensors
(A and B), replace sensor
if required
F b7
Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
Coding card not in-
serted in the burner
control unit; incor-
rect or faulty cod-
ing card
Insert coding card; check
coding card; replace if re-
quired
Troubleshooting
Fault codes
(cont.)
5794 780 GB
Summary of Contents for 7502860
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