Viessmann Vitoladens 300-C Service Instructions Manual page 66

Troubleshooting
Fault codes
(cont.)
Fault code System characteris-
on the dis- tics
play
F2 Burner in a fault
state
F3 Burner in a fault
state
F4 Burner in a fault
state
F5 Burner in a fault
state
F6 Burner in a fault
state
F8 Burner in a fault
state
F9 Burner in a fault
state
66
Cause
The temperature
limiter has respon-
ded
Flame signal is
already present at
burner start
The flame is not
established at the
end of the safety
time
The air pressure
switch does not
respond.
No control/feed-
back of/from fuel
valve BV 2
Fuel valve BV 1
closes late
Fan speed too low
during the burner
start
Measures
Check the heating system
fill level. Check the circu-
lation pump. Vent the sys-
tem. Check the tempera-
ture limiter and connect-
ing cables.
Press "E".
Check ignition electrodes,
electrode gaps and con-
necting cables.
Press "E".
Check oil supply, ignition
electrodes, electrode
gaps and connecting
cables,
check nozzle, check sole-
noid valve coil.
Correct all settings, if
required, clean all conta-
minated parts and replace
faulty components.
Press "E".
Check air pressure switch
and replace if necessary.
Press "E".
Replace solenoid valve
BV 2.
Press "E".
Check nozzle; vent oil
supply line; check sole-
noid valve.
Press "E".
Check the fan, check the
fan connecting cables,
check the fan power sup-
ply.
Press "E".