Viessmann VITODENS 200-W Service Instructions Manual page 107

Fault codes
(cont.)
Dis- Const. Weath.-
played comp.
fault
code
F8 X X
F9 X X
FA X X
FC X X
Fd X X
System char- Cause
acteristics
Burner in a fault The fuel valve
state closes too
late
Burner in a fault Fan speed
state too low during
burner start
Burner in a fault Fan not at
state standstill
Burner in a fault Gas train
state faulty or faulty
modulation
valve control
or flue gas
path blocked
Burner in a fault Fault, com-
state bustion con-
troller
Troubleshooting
Measures
Check the gas
train. Check both
control paths.
Press reset button
R.
Check the fan, the
fan connecting
cables and power
supply; check the
fan control.
Press reset button
R.
Check the fan, fan
connecting cables
and fan control.
Press reset button
R.
Check the gas
train. Check the
flue gas system.
Press reset button
R.
Check ignition
electrodes and
connecting cables.
Check whether a
strong interference
(EMC) field exists
near the appliance.
Press reset button
R.
Replace control
unit if the fault per-
sists.
107