Viessmann VITOCROSSAL 200 Service Instructions Manual page 48

Troubleshooting
Diagnosis
(cont.)
Fault Display
*1
code
F 53 9
F 54 F 54
F 55 F 55
Internal system fault
Internal system faults are created if a perfect program sequence can no longer be
guaranteed.
All fault codes are saved to the fault memory and the last 10 can be called up.
*1
48
System charac-
teristics
Shortage of gas to
gas pressure lim-
iter; check valve
tightness
PWM values
incorrect
Parameter mem-
ory stick fault
Cause
Gas valve does
not open; gas
valve leaking
EEPROM of
memory stick
modified or
deleted; stick
faulty
Memory stick
faulty
Measure
Replace gas train.
After replacing the
gas train extended
reset (see
page 45)
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.
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