76
Fault number
on the display
System characteristics
Cause
Measures
F.346
Burner in a fault state
Ionisation current calibra-
tion error
■
Check the gas supply pressure.
Check gas train strainer on the
inlet side for contamination.
■
Check ionisation electrode for
contamination.
Check gap between ionisation
electrode and burner gauze as-
sembly (see page 43).
Reset the appliance.
■
Check flue system; remove flue
gas recirculation if required.
■
Check the connecting cable to
the fan unit.
■
Check impeller for ease of opera-
tion.
Reset the appliance.
F.348
Burner in a fault state
Gas modulation valve
Check connecting cables to the
gas train for damage.
Check the flue system for flue gas
back pressure.
Check gas train.
Reset the appliance.
F.349
Control mode
Burner is operating with a
limited modulation range.
Air mass rate flow not de-
tected correctly in fan unit.
Check mass flow sensor on the fan
unit. Check the flue system for flue
gas back pressure.
F.350
Burner in a fault state
Ionisation voltage lies out-
side the permissible range
Check ionisation electrode and
connecting cable.
Reset the appliance.
F.351
Burner in a fault state
Ionisation current lies out-
side the permissible range
Check ionisation electrode and
connecting cable.
Reset the appliance.
F.352
Burner in a fault state
CO limit within appliance
exceeded.
Check entire flue gas path for the
following:
■
Flue gas recirculation
■
Leaks
■
Flue gas back pressure caused
by water pocket (if flue system
fall is insufficient)
■
Constrictions
■
Blockages
Repair flue system if necessary.
Reset the appliance.
F.353
Burner locked out
Insufficient gas supply,
burner output reduced.
Check the gas supply.
Optically check input-side screen
in the gas train for contamination.
Reset the appliance.
F.354
Burner in a fault state
Gas modulation valve tol-
erance outside permissi-
ble range
Check connecting cables to the
gas train for damage.
Check gas train.
Check the flue system for block-
ages or constrictions.
Reset the appliance.
Troubleshooting
Fault messages
(cont.)
6130884
Service