Viessmann Vitocrossal 200 Service Instructions Manual page 45

Diagnosis
(cont.)
Faults without fault display
Fault
Combustion fault through
pulsation
Burner restarts and
switches off after the
safety period has expired
CO is formed or burner is
very sooty
CO content too low
2
Excessive flue gas tem-
perature
Whining noises
Cause
Excessive gas through-
put
Air shortage or excess
Condensate backup in
flue gas system
Incorrect flue draught
Cores "L1" and "N" at
the power supply term-
inals of the control unit
interchanged
Air shortage or excess
Insufficient chimney
draught
Incorrect setting
Excessive gas through-
put
Incorrect CO settings
2
Troubleshooting
Measures
Adjust the gas throughput
in accordance with the
rated boiler output
Adjust the gas throughput
in accordance with the
rated boiler output.
Check the condensate
drain.
Check flue draught.
Check the power supply
and interchange the
cores.
Adjust correctly. Check
the ventilation of the boil-
er room.
Check the flue gas sys-
tem.
Check that burner has
been adjusted for the cor-
rect gas type and change
the gas restrictor, if re-
quired (see from page 9).
Adjust the burner in ac-
cordance with the details
on page 14.
Adjust the gas throughput
in accordance with the
rated boiler output (see
supply values, page 62).
Check the condition of
the secondary heating
surfaces of the boiler and
clean them, if required.
Adjust the burner in ac-
cordance with the details
on page 14.
45