Viessmann Vitodens 100-W Installation And Service Instructions Manual page 40

Troubleshooting
Fault display
Fault code System character-
displayed istics
FA Burner in a fault
state
FC Burner blocked
Fd Burner blocked
FF Burner blocked
40
(cont.)
Cause
Fan idle state not
reached
Electrical fan con-
trol (control unit)
faulty
Burner control unit
fault
Burner control unit
fault
Measures
Check fan, fan connect-
ing cables and fan con-
trol.
Press "Reset" (see
page 41).
Check fan connecting ca-
bles; if required, replace
or replace control unit.
Check ignition electrodes
and connecting cables.
Check whether a strong
interference (EMC) field
exists near the appliance.
Press "Reset" (see
page 41).
Replace control unit if
fault persists.
Check ignition electrodes
and connecting cables.
Check whether a strong
interference (EMC) field
exists near the appliance.
Press "Reset" (see
page 41).
Replace control unit if
fault persists.