94
Fault code dis-
played
System characteristics
Cause
Measures
EE
Burner in a fault state
Flame signal at burner
start not present or insuffi-
cient.
■
Check gas supply (gas pressure
and gas flow switch).
■
Check gas train.
■
Check system for condensate
backup.
Note
To prevent water damage, de-
tach fan unit before removing the
burner.
■
Check ionisation electrode and
connecting cable.
Check ignition:
■
Connecting cables to ignition
module and ignition electrode
■
Ignition electrode gap and con-
tamination (see page 41).
Press reset button
R
.
EF
Burner in a fault state
Flame is lost immediately
after flame formation (dur-
ing safety time)
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode (replace
if necessary):
■
Distance to burner gauze assem-
bly (see page 41)
■
Electrode contaminated
Press reset button
R
.
F0
Burner blocked
Internal fault
Replace control unit.
F1
Burner in a fault state
Flue gas temperature lim-
iter has responded.
Check heating system fill level.
Vent the system.
Press reset button
R
after flue sys-
tem has cooled down.
F2
Burner in a fault state
Temperature limiter has
responded.
Check heating system fill level.
Check circulation pump. Vent the
system. Check temperature limiter
and connecting cables.
Press reset button
R
.
F3
Burner in a fault state
Flame signal is already
present at burner start.
Check ionisation electrode and
connecting cable.
Check system for condensate
backup.
Note
To prevent water damage, detach
fan unit before removing the burn-
er.
Press reset button
R
.
F8
Burner in a fault state
Fuel valve or modulation
valve will not close.
Check the gas train and replace if
required.
Press reset button
R
.
Troubleshooting
Fault codes
(cont.)
5778741
Diagnosis