Viessmann Vitoligno 300-P Service Instructions For Contractors page 84

Troubleshooting
Fault display
Fault code System characteris-
on the dis- tics
play
F2 Emergency mode,
i.e. controlled opera-
tion with max. fan
speed
F3 Boiler enters burnout
phase; burner
blocked
F4 Control mode
F5 Burner blocked
F6 Burner blocked
F7 Burner stop initiation
F9 Burner blocked
FA Control mode
FB Burner blocked
FC Burner blocked
84
(cont.)
Cause
Secondary air
damper faulty
Flue gas fan faulty Check fan and replace, if
Open ash door
Pellets are not igni-
ted (flame temper-
ature not reached)
Internal electronics
fault
Safety chain bro-
ken
Grate cleaning
faulty
Because of jam-
med pellets, grate
does not return into
its original position
Cleaning motor for
secondary heating
surface faulty
Supply system
faulty
Fuel shortage rec-
ognised (flame
temperature not
achieved)
Measures
Check mechanics, drive
and microswitch and
replace, if required
required
Close ash door
Check ignition element,
supply system, flame tem-
perature sensor, possibly
refill with pellets, check
timer connection.
Remove unburned pellets
from the ash container
(see page 40), automatic
cleaning starts
Replace PCB A2 if
required
Check connection of all
external safety equip-
ment
Check mechanics, drive
and microswitch and
replace, if required
Release grate drive and
move grate with pliers or
similar tools unti it is free
again. Then refit grate
drive
Check mechanics, drive
and microswitch and
replace, if required
Check supply system
Check supply system,
flame temperature sensor
and refill with pellets, if
required