Viessmann Flue gas system Installation Instructions Manual page 4

General installation instructions (cont.)
Leak/soundness test
Flue gas system with Building Regulations approval -
Routing through a duct
After their installation, flue gas systems
routed through a duct must be tested for
soundness by a competent person as per
the Building regulations.
Pressurised flues inside buildings that are
n
not surrounded by combustion air (open
flue) must be pressure tested.
To pressure test a flue, air is pumped into
the flue that has been sealed at the top
and bottom using a flue test device, until
a pressure of 200 Pa has built. Whilst
maintaining this pressure, the volume
of air that escapes through leaks is
established.
Up to a leakage rate of 0,006 litres/ (s x
m ), relative to the internal surface area,
2
is considered as indication that the flue is
sound.
Flue gas systems as technical units with Vitodens and Vitoladens
Balanced flue roof outlet (C
n
Balanced flue external wall terminal (C
n
Routing over external walls (C
n
Separate ventilation and flue gas routing
n
(C )
53x
We recommend that a simple soundness
test is carried out during the commissioning
of your system. For this it would be
sufficient to check the CO
the combustion air at the annular gap of the
balanced flue pipe. The flue pipe is deemed
to be sound if the CO
)
33x
13x
)
53x
concentration in
2
concentration in the
2
In pressurised flue gas systems that are
n
surrounded by combustion air (balance
flue), the soundness can be checked by
testing the O
air (annular gap test).
The flue is reckoned to be sufficiently
sound if the O
air deviates by no more than the following
values from the reference value. The
reference value results after the self-
adjustment of the test equipment:
– for flues with general Building
Regulations approval 0.4% by vol.
– for other flues 0.2% by vol.
combustion air is no higher than 0.2% or
the O concentration is at least 20.6%.
)
2
If higher CO
2
measured, check the flue system for
soundness.
content in the combustion
2
content in the combustion
2
or lower O values are
2
3