Viessmann MPA51 Operating And Service Instructions page 23

Diagnosis
(cont.)
Fault
Whining noises
CO content too
2
low
CO is formed or
burner is very sooty
Excessive flue gas
temperature
Cause
Incorrect CO set-
2
tings; insufficient or
excessive air
Incorrect setting
Insufficient or too
much air
Insufficient draught
in flue system
Excessive gas
throughput
Measures
Adjust burner according to the informa-
tion in the Vitocrossal service instruc-
tions.
Check that the burner has been set for
the correct gas type, change gas restric-
tor if required (see Vitocrossal service in-
structions).
Adjust burner according to the informa-
tion in the Vitocrossal service instruc-
tions.
Correct settings. Check ventilation in in-
stallation room.
Check flue system.
Adjust the gas throughput according to
the rated boiler heating output (see con-
nection values in the Vitocrossal service
instructions).
Check condition of secondary heating
surfaces of the boiler and clean if re-
quired.
Diagnosis
23