Operating instructions

Fault
code
on the
display
Const. weath.-
comp.
System char-
acteristics
Cause Measures
F2 X X Burner in a
fault state
The tem-
perature lim-
iter has
responded.
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".
F3 X X Burner in a
fault state
Flame signal
is already
present at
burner start.
Check the ionisa-
tion electrode and
connecting cable.
Press "E
RESET".
F4 X X Burner in a
fault state
No flame sig-
nal.
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".
F8 X X Burner in a
fault state
The fuel
valve closes
too late
Check the gas
train. Check both
control paths.
Press "E
RESET".
Fault codes (cont.)
77
Troubleshooting
5692 672 GB