Viessmann Vitoplus 300 - Page 74

Display fault
code
System char-
acteristics
Cause Measures
F6 Burner control
unit fault
No control/feedback of/
from fuel valve BV 2
Replace fuel
valve BV 2.
Press "E".
F8 Burner control
unit fault
The fuel valve 1 closes
too late
Check the nozzle,
vent the oil supply
pipe,
check the sole-
noid valve.
Press "E".
F9 Burner control
unit fault
Fan speed too low during
burner start
Check the fan,
check the fan con-
necting cables,
check the fan
power supply.
Press "E".
Burner control
unit fault
The fan power supply is
interrupted.
&
The fire protection
switch or flue gas ther-
mostat is faulty or has
responded
&
The jumper across
terminals 1 and 2 in wir-
ing chamber 201 is bro-
ken or has been
removed
Check the fire
protection switch
or the flue gas
thermostat.
Check the jumper
in wiring chamber
201 (see page
100).
Press "E".
FA Burner control
unit fault
Fan speed — deviation Check the fan and
the fan connecting
cables,
Press "E".
Fd Burner
blocked
Burner control unit fault Press "E".
Replace the con-
trol unit if the dis-
play shows "Fd"
again.
FB Burner control
unit fault
Flame blow-off three
times during operation
Check the oil sup-
ply; check the
nozzle.
Press "E".
Fault codes (cont.)
74
Troubleshooting
5692 536 GB