Checking The Balanced Flue System Soundness (Annular Gap Check) - Viessmann Vitodens 333 Service Instructions Manual

Initial start-up, inspection, maintenance
Further details regarding the individual steps
2. K + F press simultaneously:
"100" flashes (equals
100% of rated output)
and "A" is displayed.
On weather compen-
sated control units, the
display additionally
shows "Max. output".
a/b press for the required
value in % of rated output
as max. output.
d to confirm.
Checking the balanced flue system soundness (annular gap
check)
For balanced flue systems tested together with the wall mounted gas fired boil-
er, some authorities waive the requirement for a soundness test (overpressure
test) during commissioning by the flue gas inspector.
We recommend that your heating engineer carries out a simple leak test during
the commissioning of your system. For this it would be sufficient to check the
CO concentration in the combustion air at the annular gap of the balanced flue
2
pipe.
A Combustion air port (ventilation
air)
18
(cont.)
3. Record the setting for max. output
on the additional type plate sup-
plied with the "technical documen-
tation". Affix the type plate next to
the type plate on top of the boiler.
The flue pipe is deemed to be sound if
the CO concentration in the combus-
2
tion air is no higher than 0.2% or the
O concentration is at least 20.6%.
2
If actual CO values are higher or O
2
values are lower, then pressure test
the flue pipe with a static pressure of
200 Pa.
2