40
Displayed fault
code
System characteristics
Cause
Measures
F E5
Burner control unit in a fault
state
Internal fault of the burner
control unit and during test
of ionisation input
Replace burner control unit.
F EB
Burner locked out
Burner not enabled via ex-
ternal contact.
Check component connected to
TR/TR EIN at plug
aBÖ
of the
Vitotronic.
F EC
Burner control unit in a fault
state
Internal error in feedback
from safety relay.
Reset burner control unit. Replace
burner control unit if required.
F ED
Burner control unit in a fault
state
Internal error in feedback
from ignition relay.
Reset burner control unit. Replace
burner control unit if required.
F EE
Burner control unit in a fault
state
Internal error in feedback
from gas safety valves.
The output relay does not
respond.
Reset or replace burner control
unit.
F EF
Burner control unit in a fault
state
Internal error in feedback
from gas safety valves.
The output relay does not
respond.
Reset or replace burner control
unit.
F F1
Burner control unit in a fault
state; system cools down.
Flue gas temperature lim-
iter has responded
■
Flue gas temperature
too high
■
Excessive gas through-
put
■
Wait until temperature falls below
the permissible flue gas tempera-
ture.
■
Check the system pressure.
■
Check heat exchanger surfaces
for contamination.
■
Reset burner control unit.
■
Check the CO
2
setting.
■
Adjust gas throughput in accord-
ance with the rated boiler heating
output. See "Specification" for
connected values.
F F2
Burner control unit in a fault
state; system cools down.
Boiler water temperature
limiter has responded.
Boiler water temperature
too high.
■
Wait until temperature falls below
the permissible boiler water tem-
perature.
■
Reset burner control unit.
F F3
Ionisation flame monitor re-
ports faulty flame signal dur-
ing start-up or after the post-
purge.
Ionisation electrode or burner
gauze assembly damaged.
Gas train leaks (gas is es-
caping and burning). In-
correct coding card.
Check ionisation path. Check ioni-
sation electrode for earth fault.
Check burner gauze assembly for
deformation.
Replace coding card. Replace gas
train.
F F4
No flame formation during
safety time; ionisation flame
monitor reports no flame sig-
nal.
Ionisation electrode incor-
rectly adjusted; ionisation
electrode not plugged in.
Earth leakage of electrode
or cable.
Insert plug of ionisation electrode;
check cable; adjust ionisation elec-
trode (see page 24).
F F4
No flame formation during
safety time; ionisation flame
monitor reports no flame sig-
nal.
Ignition electrodes incor-
rectly adjusted, electrode
earth fault, ignition unit
faulty, burner control unit
faulty
Adjust ignition electrodes (see
page 24); replace ignition unit. Re-
place burner control unit.
F F4
No flame formation during
safety time; ionisation flame
monitor reports no flame sig-
nal.
Insulation body of ignition
or ionisation electrode
cracked
Replace ignition or ionisation elec-
trode.
Troubleshooting
Fault codes with display on burner control unit
(cont.)
5833296
Diagnosis
