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91
5673 649 - 18
Vitocrossal 300 CU3A 26 to 199 Service
Troubleshooting
Fault Codes
(continued)
Fault code on display
System behavior
*1
Cause
Corrective action
EE
Burner in a fault mode
At burner start, flame
signal is missing or too
weak
Check gas supply (gas pressure
and gas regulator). Check gas
train. Check ionization electrode
and connecting cable.
Check ignition:
- Connecting leads to ignition
module and ignition electrode.
- Ignition electrode gap and
contamination (see page 23).
Check condensate drain.
Press reset button
R
.
EF
Burner in a fault mode
Flame is lost immediately
after it has built (during
the safety time)
Check gas supply (gas pressure
and gas regulator). Check flue
gas/ventilation air system for
flue gas recirculation. Check
ionization electrode (replace
if required):
- Distance to burner gauze
assembly (see page 23).
- Contamination of electrode
Press reset button
R
.
- Check combustion air/common
combustion air intake for
blockages.
- replace air intake adaptor.
F0
Burner blocked
Internal fault
Replace the control unit.
F1
Burner in a fault mode
Maximum flue gas
temperature exceeded
230ºF (110ºC) limit.
Check heating system fill level.
Bleed air from system. Check
circulation pump. Check boiler
water temperature sensor and
cable. Press reset button
R
after
vent system has cooled down.
F2
Burner in fault mode
Fixed high limit switch
open (activated)
Check heating system fill
level. Check the circulation
pump. Bleed air from the
system. Check fixed high limit
switch and connecting cables.
Press reset button
R
.
F3
Burner in fault mode
Flame signal already
present at burner start
Check the ionization electrode
and connecting cable.
Press reset button
R
.
*1
Control mode:..............Boiler/burner fully operational (fault code must be verified and reset).
Burner in fault mode:.....Boiler control requires manual reset before burner can resume operation.
Burner blocked: ...........If fault cause is corrected, burner resumes operation.