Operating instructions

Fault
code in
the dis-
play
Const. Weath.-
comp.
System char-
acteristics
Cause Remedy
F8 X X Burner fault The fuel
valve closes
too late
Check the gas
combination valve
and both control
paths; pres s "E"
F9 X X Burner fault Fan spee d
too low dur-
ing burner
start
Check the fan, fan
connecting
cables, fan power
supply and con-
trol; press "E"
FA X X Burner faul t Fan not at
standstill
Check fan, fan
connecting cables
and fan control;
press "E"
Fd X X Burner
blocked
Fault burner
control unit
Check the ignition
electrodes and
connecting
cables/leads;
check whether
there are strong
fields of interfer-
ence (EMC) near
the equipment;
press "E". Re-
place the c ontrol
unit if the fault
persists.
FE X X Burner
blockedorina
fault state
Strong inter-
ference
(EMC) field
nearby or
faulty main
PCB
Start the boiler
again. Replace
the control unit if
the equipment will
not restart.
FF X X Burner
blockedorina
fault state
Strong inter-
ference
(EMC) field
nearby or in-
ternal fault
Start the boiler
again. Replace
the control unit if
the equipment will
not restart.
Fault codes (cont.)
78
Troubleshooting
5692 619 GB