Operating instructions

35
Fault code
on the dis-
play
System characteris-
tics
Cause Measures
F2 Burner in a fault
state
The temperature
limiter has respon-
ded
Check the heating system
fill level. Check the circu-
lation pump. Vent the sys-
tem. Check the tempera-
ture limiter and connect-
ing cables.
Press "Reset" (see
page 36).
F3 Burner in a fault
state
Flame signal is
already present at
burner start
Check the ionisation elec-
trode and connecting
cable.
Press "Reset" (see
page 36).
F4 Burner in a fault
state
No flame signal is
present
Check the ionisation elec-
trode and leads, measure
the ionisation current,
check the gas pressure,
check the gas train, igni-
tion, ignition module and
condensate drain.
Press "Reset" (see
page 36).
F8 Burner in a fault
state
The fuel valve
closes too late
Check the gas train.
Check both control paths.
Press "Reset" (see
page 36).
F9 Burner in a fault
state
Fan speed too low
during the burner
start
Check the fan, check the
fan cables and supply;
check the fan control.
Press "Reset" (see
page 36).
FA Burner in a fault
state
Fan not at stand-
still
Check the fan, fan con-
necting cables and fan
control.
Press "Reset" (see
page 36).
FC Burner blocked Electrical fan con-
trol (control unit)
faulty
Check fan connecting
cable; if required, replace
or replace control unit
Troubleshooting
Fault messages on the display
(cont.)
5366 836 GB
Service