Viessmann Vitodens 300 Service Instructions Manual page 84

Troubleshooting
Checking and acknowledging faults
Displayed Const.
fault code
FA X
Fd X
FE X
84
Weat- System
her- character-
comp. istics
X Burner in
fault state
X Burner
blocked
X Burner
blocked
(cont.)
Cause Remedy
Fan speed too high Check the
at burner start fan, check the
fan cables,
check the fan
control.
Press E.
Burner control unit Check the
fault ignition elec-
trodes and
leads. Check
whether a
strong inter-
ference
(EMC) field
exists near
the equip-
ment.
Press E.
If the fault is
not removed,
replace the
control unit.
Strong interference Remove EMC
(EMC) field nearby; interference.
alternatively boiler If the equip-
coding card or ment will not
main PCB faulty restart, check
the boiler
coding card
and replace,
or replace the
control unit.