Viessmann Vitoflame 100 Service Instructions Manual page 27

Diagnosis
(cont.)
Faults without flashing code display
Fault
Burner does not
start (no fault dis-
play), indicator does
not illuminate
When changing
from stage 1 to
stage 2 the flame
extinguishes and
the burner starts
again
Burner sooty
Cause
No voltage
High limit safety cut-out acti-
vated
The low water indicator has
caused the system to shut
down
Motor faulty
Servomotor faulty
Flame monitor contaminated
Inside of flame tube contami-
nated
Sensor plate contaminated
Faulty control unit
Too little or too much air
Insufficient chimney draught
Nozzle faulty
The flame tube extension is
missing
Incorrect setting of the 0-point
of the blast tube connection
Troubleshooting
Measures
Check fuse or connector aBÖ
in the control unit, the electrical
connections, the setting of the
ON/OFF switch on the control
unit and the mains isolator
Press reset button on the boiler
control unit
Check the water level; top-up if
required. Press the reset but-
ton on the burner.
Replace motor
Replace servomotor
Clean flame monitor
Clean inside of flame tube
Clean sensor plate
Replace control unit
Adjust correctly. Check and
clean impeller.
Check ventilation of installation
room.
Check flue and flue gas rout-
ing
Replace nozzle, fit right nozzle
(see chapter "Standard values
for burner settings")
Install flame tube extension
Check 0-point setting of the
blast tube connection and cor-
rect if required (see chapter
"Checking the 0-point setting of
the blast tube connection")
27