Viessmann VITOCROSSAL 200 Service Instructions Manual page 47

Diagnosis
(cont.)
Fault Display
code *1
F 40 None
F 41 F 41
F 42 F 42
F 43 F 43
F 50 F 50
*1 All fault codes are saved to the fault memory and the last 10 can be called up.
System charac-
teristics
Burner control unit
in fault state
Varying fan speed Fan faulty; cable
No fan feedback
Burner control unit
in fault state
Burner control unit
in fault state
Cause
Set default value
for fan in parame-
ter set incorrect
"100A" faulty or
broken; fan
unsuitable for the
required speed
Fan faulty; exter-
nal power supply
to fan not connec-
ted or faulty; cable
"100A" faulty or
broken; fan
blocked (poss. by
a foreign body)
Internal fault of the
burner control unit
and during test of
ionisation input
Internal fault in
servomotor feed-
back; output relay
does not respond
Troubleshooting
Measure
Replace memory
stick
I Danger
Plug-in termi-
nals on the
burner control
unit 'live'.
Only replace
stick when the
power has
been isolated
from the
burner control
unit
Check cable and
replace cable
"100A" or fan if
required
Check cable
"100A"; check
external power
supply; replace
cable or fan;
remove foreign
bodies
Replace burner
control unit
Replace burner
control unit
47