Viessmann VITOLADENS333-F Service Instructions Manual page 73

Fault codes
(cont.)
Fault code System character-
on the dis- istics
play
F5 Burner in a fault
state
F7 Burner in a fault
state
F8 Burner in a fault
state
F9 Burner in a fault
state
F9 Burner in a fault
state
FA Burner in a fault
state
Fb Burner in a fault
state
Fd Burner blocked
Cause Measures
The air pressure Check air pressure
switch does not switch and replace if ne-
respond. cessary.
Press "E RESET".
No control/feed- Replace fuel valve BV 2
back of/from fuel Press "E RESET".
valve BV 2
Fuel valve BV 1 Check nozzle, vent oil
closes late supply line, check sole-
noid valve
Press "E RESET".
Fan speed too Check the fan, check
low during the the fan connecting
burner start cables, check the fan
power supply.
Press "E RESET".
Fan power supply Check fire safety switch
is interrupted or smoke thermostat,
The fire safety check jumper across
switch or flue terminals 1 and 2 in
gas thermostat junction box 201 (see
is faulty or has page 97).
responded Press "E RESET".
The jumper
across term-
inals 1 and 2 in
junction box
201 is broken or
has been
removed
Fan speed devia- Check fan, check con-
tion necting cables to fan.
Press "E RESET".
3 x flame blow-off Check oil supply, check
during operation nozzle.
Press "E RESET".
Burner control Press "E RESET" . Re-
unit fault place control unit if the
fault persists
Troubleshooting
73