50
Fault
Cause
Measure
CO
2
content too low
Incorrect setting
Check that burner has been adjusted
for the correct gas type, and change
gas restrictor if required (see from
page 11).
Adjust burner in accordance with the
details on page 14
CO is formed or burner
is very sooty
Too little or too much
air
Adjust correctly. Check ventilation of
installation room
Insufficient draught in
flue gas system
Check flue system
Excessive flue gas
temperature
Excessive gas
throughput
Adjust gas throughput in accordance
with rated boiler output (see supply
values, page 71).
Check condition of secondary heat-
ing surfaces of the boiler, and clean
if required
Troubleshooting
Diagnosis
(cont.)
5692 908 GB