Faults Without Fault Display - Viessmann Vitocrossal 300 Service Instructions Manual

Diagnosis
(cont.)

Faults without fault display

Fault
Combustion faults due to
pulsation
Whining noises
CO content too low
2
CO formation or burner is
very sooty.
Excessive flue gas tem-
perature
Cause of fault
Excessive gas throughput
Insufficient or excessive air
Condensate backed up in
flue system
Flue outlet not installed cor-
rectly
Incorrect CO settings; insuf-
2
ficient or excessive air
Incorrect setting
Insufficient or excessive air
Insufficient draught in flue
system
Excessive gas throughput
Measure
Adjust gas throughput in accordance with the rated
boiler heating output.
Adjust gas throughput in accordance with the rated
boiler heating output.
Check condensate drain.
Check flue outlet.
Adjust burner in accordance with the details on
page 12 onwards.
Check whether the burner has been adjusted to the
correct gas type; change gas restrictor if required (see
page 10 onwards).
Adjust burner in accordance with the details on
page 12 onwards.
Correct the settings. Check ventilation in installation
room.
Check flue system.
Adjust gas throughput in accordance with rated boiler
heating output (see connection values, page 56).
Check condition of secondary heating surfaces of the
boiler and clean if required.
Troubleshooting
37