Viessmann VITODENS 111-W Installation And Service Instructions Manual page 42

Troubleshooting
Fault display
(cont.)
Fault code dis- System characteristics
played
F2 Burner in a fault state
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
Press reset (reset burner control unit)
Tap and hold R for approx. 2 s.
If the fault has been rectified, fault symbol " " disap-
pears and the default display is shown or a further fault
message is displayed.
If the fault persists, the fault message appears again.
42
Cause
Temperature limiter has
responded.
Flame signal is already
present at burner start.
No flame signal.
Fuel valve closes too late. Check gas train. Check both con-
Fan speed too low during
burner start
Fan idle state not reached Check the fan, fan connecting ca-
Electrical fan control (con-
trol unit) faulty
Burner control unit fault
Burner control unit fault
Measures
Check heating system fill level.
Check circulation pump. Vent the
system. Check the temperature
limiter and connecting leads (see
page 47).
Press "Reset" (see page 42).
Check ionisation electrode and
connecting cable.
Press "Reset" (see page 42).
Check the ignition/ionisation elec-
trode and connecting cable, gas
pressure, gas train, ignition and
condensate drain.
Press "Reset" (see page 42).
trol paths.
Press "Reset" (see page 42).
Check the fan, fan connecting ca-
bles, fan power supply and fan
control.
Press "Reset" (see page 42).
bles and fan control.
Press "Reset" (see page 42).
Check fan connecting cable; re-
place if necessary or replace con-
trol unit.
Check ignition electrodes and con-
necting cables. Check whether a
strong interference (EMC) field ex-
ists near the appliance.
Press "Reset" (see page 42).
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 42).
Replace control unit if fault per-
sists.