Viessmann MPA51 Operating And Service Instructions page 18

Diagnosis
Diagnosis
(cont.)
Fault Display
*1
code
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
F 4b F 4b
F 4c None
All fault codes are saved to the fault memory and the last 10 can be called up.
*1
18
System charac-
teristics
Flame extinguish-
es during stabilis-
ing time
Flame extinguish-
es during stabilis-
ing time
Burner control unit
lockout
Burner switches
off; display only in
fault memory
Burner switches
off; display only in
fault memory
Burner control unit
in fault state
Burner control unit
in fault state
Parameter memo-
ry stick not found
Parameter memo-
ry stick matching
Cause
Incorrect parame-
ter memory stick
inserted
Combustion char-
acteristics not ide-
al
Burner control unit
has been reset
more than 5 times
in the last 15 min
Low voltage de-
tected
Mains failure, volt-
age failure detec-
ted
Safety chain is
'live'
EMC fault
Parameter set en-
abled, but memo-
ry stick not plug-
ged into burner
control unit. Mem-
ory stick faulty
Parameters could
not be transferred
from the stick
Measures
Replace and ena-
ble parameter
memory stick
Adjust the burner
Wait or carry out an
extended reset,
i.e. hold down reset
for approx. 10 s un-
til the fault display
begins to flash,
then immediately
release the reset
button
Check power sup-
ply
Check power sup-
ply
Check safety chain
(strapping plug
fJ)
Have your system
tested for EMC in-
terference
Plug memory stick
into burner control
unit; replace mem-
ory stick
Replace stick or
burner control unit