Viessmann Vitocrossal 300 Service Instructions Manual page 34

Troubleshooting
Diagnosis
(cont.)
Fault code Shown on
*1
display
F A7 F A7
F A7 F A7
F A8 F A8
F A8 F A8
F A8 F A8
F A8 F A8
F A9 F A9
F A9 F A9
F A9 F A9
F A9 F A9
F 04 F 04
F 11 None
F 12 None
F 13 F 13
F 16 None
All fault codes are saved to the fault memory and the last 10 can be called up.
*1
34
System characteristics
No flame reported during
safety time; ionisation
flame monitor reports no
flame signal.
I
Danger
Plug-in terminals on
the burner control
unit are live.
Check connections
"L 1", "N" and earth
conductor.
No flame reported during
safety time; ionisation
flame monitor reports no
flame signal.
Flame tears off during op-
eration
Flame tears off during op-
eration
Flame tears off during op-
eration
Flame tears off during op-
eration
Flame extinguishes dur-
ing stabilising time
Flame extinguishes dur-
ing stabilising time
Flame extinguishes dur-
ing stabilising time
Flame extinguishes dur-
ing stabilising time
Burner control unit lock-
out
Burner switches off; dis-
play only in fault memory.
Burner switches off; dis-
play only in fault memory.
Burner control unit in a
fault state
Burner control unit in a
fault state
Cause of fault
Connections "L 1" and
"N" interchanged at the
power supply terminal of
the control unit or burner
control unit.
Combustion characteris-
tics not ideal
Incorrect gas type selec-
ted
Burner gauze assembly
faulty
Incorrect parameter
memory stick inserted
Combustion characteris-
tics not ideal
Incorrect gas type
Burner gauze assembly
faulty
Incorrect parameter
memory stick inserted
Combustion characteris-
tics not ideal
Burner control unit has
been reset more than 5
times in the last 15 min.
Low voltage detected
Mains failure, voltage
failure detected
Safety chain is live
EMC fault
Measure
Check core assignment
and alter if required.
Adjust burner setting (see
page 12 onwards)
Adjust gas type setting
(see page 10)
Check burner gauze as-
sembly; replace if dam-
aged.
Replace and enable pa-
rameter memory stick.
Adjust burner setting (see
page 12 onwards)
Set correct gas type.
Check burner gauze as-
sembly; replace if dam-
aged.
Replace and enable pa-
rameter memory stick.
Adjust burner setting.
Wait or carry out an ex-
tended reset, i. e. hold
down the reset button for
approx. 10 s until the fault
display begins to flash,
then immediately release
the reset button.
Check power supply
Check power supply
Check safety chain (strap-
ping plug )
fJ
Have the system tested
for EMC interference