Faults Without Flash Code Indication - Viessmann Vitoflame 300 VHG III Service Instructions Manual

Diagnosis
(cont.)
Fault
Burner starts and flame
builds, but burner enters
fault state after safety time
expires
Flame tears off more than
3 times during operation
Ignition switches on during
operation
Condensate backup in flue
gas heat exchanger

Faults without flash code indication

Fault
Burner does not start (no
fault display), indicator
does not illuminate
When changing from stage
1 to stage 2, the flame
tears off and the burner
starts again
Burner sooty
CO content too low
2
Red flash Cause of fault
code
2 Flame monitor contaminated
×
2 Flame monitor receives insuffi-
×
cient light
2 Flame monitor faulty
×
2 Burner control unit faulty
×
2 Carbon deposits on the flame
×
tube or on the sensor plate
7 Air in suction line
×
7 Nozzle faulty
×
7 Burner incorrectly adjusted
×
7 Sensor plate contaminated
×
7 x Flame monitor contaminated
7 x Sensor plate contaminated
7 x Nozzle contaminated or faulty
7 x Siphon or neutralising system
contaminated
Cause of fault
No power
High limit safety cut-out has responded
The low water indicator has caused the
system to shut down
Servomotor faulty
Flame monitor contaminated
Inside of flame tube contaminated
Sensor plate contaminated
Faulty control unit
Solenoid valve stage 2 faulty
Insufficient or excess air
Insufficient chimney draught
Nozzle faulty
The flame tube extension is missing
Incorrect setting
Troubleshooting
Action
Clean flame monitor
Clean sensor plate
Replace flame monitor
Replace burner control unit
Clean the flame tube and sensor
plate
Seal line and filter
Replace nozzle
Set default values (see chapter
"Standard values for burner ad-
justment")
Clean sensor plate
Clean flame monitor
Clean sensor plate
Replace nozzle
Clean siphon and neutralising
system
Action
Check fuse or plug-in connector
the control unit, the electrical connec-
tions, the setting of the ON/OFF switch
on the control unit and the mains isolator
Press reset button at the boiler control
unit
Check the water level; top-up if required.
Press the reset button on the burner.
Replace the servomotor
Clean flame monitor
Clean inside of flame tube
Clean sensor plate
Replace control unit
Replace solenoid coil
Correct the settings. Check and clean im-
peller.
Check fan pressure.
Check ventilation in installation room.
Check chimney and flue gas routing
Replace the nozzle, fit the right nozzle
(see chapter "Standard values for burner
adjustment")
Install the flame tube extension
Check setting (see chapter "Standard val-
ues for burner adjustment")
in
aBÖ
19