Viessmann Vitodens 333 Service Instructions Manual page 79

Fault codes
(cont.)
Display Const. Weath.
fault comp.
code
F9 X X
FA X X
Fd X X
FE X X
FF X X
System char- Cause
acteristics
Burner control Fan speed
unit fault too low dur-
ing burner
start
Burner control Fan not at
unit fault standstill
Burner Fault at the
blocked burner con-
trol unit
Burner Strong inter-
blocked or in a ference
fault state (EMC) field
nearby or
faulty main
PCB
Burner Strong inter-
blocked or in a ference
fault state (EMC) field
nearby or in-
ternal fault
Troubleshooting
Remedy
Check the fan, fan
connecting
cables, fan power
supply and con-
trol; press "E"
Check the fan, fan
connecting cables
and fan control;
press "E"
Check the ignition
electrodes and
connecting
cables/leads;
check whether
there are strong
interference
(EMC) fields near
the equipment;
press "E" . Re-
place the control
unit if the fault
persists.
Start the boiler
again. Replace
the control unit, if
the equipment will
not restart
Start the boiler
again. Replace
the control unit, if
the equipment will
not restart
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