Viessmann Vitocrossal 200 Series Service Instructions Manual page 47

Faults without fault display
Fault
CO content too low
2
CO formation or burner
is very sooty.
Flame tears off during
operation.
Flue gas temperature
too high
(cont.)
Cause of fault
Incorrect setting
Insufficient or too much air
Insufficient draught in flue sys-
tem
Intake strainer of gas train
soiled
Gas throughput too high.
Boiler contaminated; insuffi-
cient boiler water pressure
available.
Measure
Check whether the burner has been adjusted to the
correct gas type; change gas restrictor if required (see
page 11 onwards).
Adjust burner in accordance with the details on
page 16 onwards.
Correct the settings. Check ventilation in installation
room.
Check flue system.
Remove flange and clean strainer. See page 31.
Adjust gas throughput in accordance with the rated
boiler heating output. Check condition of heating surfa-
ces. Clean if required. Check boiler for deposits on the
heating water side (scaling).
Clean boiler. Increase the boiler water pressure.
Troubleshooting
47