Viessmann VITOCROSSAL 200 Service Instructions Manual page 43

Diagnosis
(cont.)
Fault code System character-
istics
F A7 No flame signal dur-
ing the safety time;
the ionisation flame
monitor reports no
flame signal
Danger
Plug-in term-
inals on the
burner con-
trol unit 'live'
Check con-
nections "L
1", "N" and
earth con-
ductor
F A7 No flame signal dur-
ing the safety time;
the ionisation flame
monitor reports no
flame signal
F A7 No flame signal dur-
ing the safety time;
the ionisation flame
monitor reports no
flame signal
F A8 Flame extinguishes
during operation
F A8 Flame extinguishes
during operation
F A8 Flame extinguishes
during operation
F A8 Flame extinguishes
during operation
F A9 Flame extinguishes
during stabilising
time
Cause Measures
Connections "L1" Check core allocations
and "N" at the and alter if required
power supply
terminals of the
control unit or
burner control
unit interchanged
Combustion char- Adjust the burner (see
acteristics not from page 13)
ideal
Incorrect para- Set parameters; replace
meter set se- parameter memory stick
lected if required and enable
Incorrect gas type Adjust the gas type (see
selected page 10)
Burner gauze as- Replace the burner
sembly faulty gauze assembly
Incorrect para- Set parameters; replace
meter set se- parameter memory stick
lected if required and enable
Combustion char- Adjust the burner (see
acteristics not from page 13)
ideal
Incorrect gas type Adjust gas type
Troubleshooting
43