Viessmann VITODENS 100-W Installation And Service Instructions Manual page 34

Troubleshooting
Fault messages on the display
Displayed System characteris-
fault code tics
F1 Burner in a fault
state
F2 Burner in a fault
state
F3 Burner in a fault
state
F4 Burner in a fault
state
F8 Burner in a fault
state
F9 Burner in a fault
state
FA Burner in a fault
state
34
(cont.)
Cause
Max. flue gas tem-
perature exceeded
The temperature
limiter has respon-
ded
Flame signal is al-
ready present at
burner start
No flame signal de-
tected
Fuel valve closes
too late
Fan speed too low
during burner start
Fan not at stand-
still
Measures
Check heating system fill
level. Check circulation
pump. Vent the system.
Press "Reset" (see
page 36).
Check heating system fill
level. Check circulation
pump. Vent the system.
Check temperature limiter
and connecting cables.
Press "Reset" (see
page 36).
Check ionisation elec-
trode and connecting ca-
ble.
Press "Reset" (see
page 36).
Check the ionisation elec-
trode and connecting ca-
bles, check the gas pres-
sure, check the gas train,
ignition, ignition module
and condensate drain.
Press "Reset" (see
page 36).
Check gas train. Check
both control paths.
Press "Reset" (see
page 36).
Check fan, fan connecting
cables and power supply;
check fan control.
Press "Reset" (see
page 36).
Check fan, fan connecting
cables and fan control.
Press "Reset" (see
page 36).