Viessmann Vitodens 333-F Service Instructions Manual page 85

Fault codes
(cont.)
Fault Const. weath.-
code comp.
on the
display
F2 X X
F3 X X
F4 X X
F7 X X
System char- Cause
acteristics
Burner in a The tem-
fault state perature lim-
iter has
responded.
Burner in a Flame signal
fault state is already
present at
burner start.
Burner in a No flame sig-
fault state nal.
Burner Short circuit
blocked or water
pressure
sensor lead
broken
Troubleshooting
Measures
Check the heating
system fill level.
Check the circula-
tion pump. Vent
the system.
Check the tem-
perature limiter
and connecting
cables.
Press "E
RESET".
Check the ionisa-
tion electrode and
connecting cable.
Press "E
RESET".
Check the ionisa-
tion electrode and
cable, measure
the ionisation cur-
rent, check the
gas pressure,
check the gas
train, ignition,
ignition module,
ignition electro-
des and the con-
densate drain.
Press "E
RESET".
Check the water
pressure sensor
and the intercon-
necting cable.
85