Operating instructions

127
Dis-
played
fault
code
Const. Weath.-
comp.
System char-
acteristics
Cause Measures
F3 X X Burner in a fault
state
Flame signal
is already
present at
burner start.
Check ionisation
electrode and con-
necting cable.
Press reset button
R.
F8 X X Burner in a fault
state
Fuel valve
closes too
late.
Check gas train.
Check both control
paths.
Press reset button
R.
F9 X X Burner in a fault
state
Fan speed
too low during
burner start
Check fan, fan con-
necting cables and
power supply;
check fan control.
Press reset button
R.
FA X X Burner in a fault
state
Fan not in idle
state
Check fan, fan con-
necting cables and
fan control.
Press reset button
R.
FC X X Burner in a fault
state
Gas train faul-
ty, faulty mod-
ulation valve
control or flue
gas path
blocked
Check gas train.
Check flue sys-
tem.
Press reset button
R.
Fd X X Burner in a fault
state and fault
message b7 is
displayed
Boiler coding
card is miss-
ing
Insert the boiler
coding card.
Press reset button
R.
Replace control
unit if fault per-
sists.
Troubleshooting
Fault codes
(cont.)
5772 909 GB
Service