83
Displayed
fault code
Const.
Weath.-
comp.
System characteris-
tics
Cause
Measures
Fd
X
X
Burner in a fault state Fault, burner con-
trol unit
Check ignition electrodes
and connecting cables.
Check whether a strong
interference (EMC) field
exists near the appliance.
Press reset button
R
.
Replace control unit if
fault persists.
FE
X
X
Burner blocked or in
a fault state
Boiler coding card
or main PCB faulty,
or incorrect boiler
coding card
Press reset button
R
. If
the fault persists, check
the boiler coding card and
replace boiler coding card
or control unit if necessa-
ry.
FF
X
X
Burner blocked or in
a fault state
Internal fault or re-
set button
R
blocked
Restart the appliance. Re-
place the control unit if
the appliance will not re-
start.
Repair
Checking the outside temperature sensor
X3
Fig. 44
100
10
-20 -10 0 10 20 30
Temperature in °C
6
8
20
40
60
80
200
Resistance
in kΩ
Fig. 45
Sensor type: NTC 10 k
Ω
1.
Pull plug "X3" from the control unit.
2.
Test the resistance of the outside temperature sen-
sor across terminals "X3.1" and "X3.2" on the dis-
connected plug and compare it with the curve.
3.
Where actual values deviate severely from the
curve values, disconnect the wires at the sensor
and repeat the test on the sensor itself.
4.
Depending on the result, replace the lead or the
outside temperature sensor.
Troubleshooting
Fault codes
(cont.)
5772 980 GB
Service
