Viessmann VITODENS 200-W Service Instructions Manual page 75

Fault codes
(cont.)
Fault Const. Weath.-
code on comp.
the dis-
play
F8 X X
F9 X X
FA X X
FC X X
Fd X X
System char- Cause
acteristics
Burner in a fault Fuel valve
state closes too
late
Burner in a fault Fan speed
state too low during
the 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 "E
RESET".
Check the fan,
check the fan con-
necting cables and
power supply;
check the fan con-
trol.
Press "E
RESET".
Check the fan, fan
connecting cables
and fan control.
Press "E
RESET".
Check the gas
train. Check flue
gas system.
Press "E
RESET".
Check ignition
electrodes and
connecting cables.
Check whether a
strong interference
(EMC) field exists
near the equip-
ment.
Press "E
RESET".
Replace control
unit if the fault per-
sists.
75