Viessmann VITODENS 111-W Installation And Service Instructions Manual page 41

Fault display
(cont.)
Fault code dis- System characteristics
played
F3 Burner in a fault state
F4 Burner in a fault state
F8 Burner in a fault state
F9 Burner in a fault state
FA Burner in a fault state
FC Burner blocked
Fd Burner blocked
FF Burner blocked
Reset activation (reset burner control unit)
Touch R for approx. 2 s.
If the fault has been removed, the fault symbol " " dis-
appears and the default display is shown or a further
fault message is displayed.
If the fault persists, the fault message appears again.
Cause
Flame signal is already
present at burner start
There is no flame signal
Fuel valve closes too late
Fan speed too low during
burner start
Fan idle state not reached Check fan, fan connecting cables
Electrical fan control (con-
trol unit) faulty
Burner control unit fault
Burner control unit fault
Troubleshooting
Measures
Check ionisation electrode and
connecting cable.
Press "Reset" (see page 41).
Check the ignition/ionisation elec-
trode and connecting cable, gas
pressure, gas train, ignition and
condensate drain.
Press "Reset" (see page 41).
Check gas train. Check both con-
trol paths.
Press "Reset" (see page 41).
Check fan, fan connecting cables
and power supply to fan; check fan
control.
Press "Reset" (see page 41).
and fan control.
Press "Reset" (see page 41).
Check fan connecting cable; re-
place if required, or replace control
unit.
Check ignition electrodes and con-
necting cables. Check whether a
strong interference (EMC) field ex-
ists near the appliance.
Press "Reset" (see page 41).
Replace control unit if fault per-
sists.
Check ignition electrodes and con-
necting cables. Check whether a
strong interference (EMC) field ex-
ists near the appliance.
Press "Reset" (see page 41).
Replace control unit if fault per-
sists.
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