Wolf CGB-75 Installation And Operating Instructions Manual page 49

General information
For reasons of operational safety, use only original Wolf
components for balanced flues and standard flues.
Where necessary, adapt the installation examples to the rel-
evant building regulations and requirements in your country/
region. Discuss any questions relating to the installation of
inspection covers and vents with the local flue gas inspector.
At low outside temperatures, the water vapour
contained in the flue gas may condense and
freeze on the air/flue gas routing system. This
ice may fall from the roof causing injuries or
material losses. Prevent falling ice with suitable
measures, e.g. installation of a suitable snow
guard.
If the balanced flue crosses different floors,
route the pipes outside the boiler room inside
a duct with a fire resistance of at least 90 min.,
and in living space of low height with a resist-
ance of at least 30 min. Fire may spread if these
instructions are not observed.
Gas condensing boilers with a balanced flue
outlet above the roof may only be installed in
attics, or in rooms where the ceiling also forms
the roof, or where only the roof construction is
located above the ceiling.
The following applies to gas boilers with a balanced flue
above the roof, where only the roof structure lies above
the ceiling:
If fire resistance is required for the ceiling, the
pipes for combustion air supply and flue gas
must be equipped with a casing in the area
between the top edge of the ceiling and the
roof skin. The casing must provide the same
fire resistance as the ceiling and must be made
from non-combustible materials. There is a risk
of fire spreading if these requirements are not
observed.
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28. Technical information
No clearance is required between the concentric balanced
flue and combustible materials or components, as tem-
peratures above 85°C will not occur at the rated heating
output.
If only a standard flue is installed, maintain the clearances
specified by DVGW/TRGI 2008 [or local regulations].
If fire resistance is not required for the ceiling,
route the ducts for combustion air supply and
flue gas expulsion between the top edge of the
ceiling and the roof skin inside a duct made
from non-combustible, rigid materials or inside
a protective metal pipe (mechanical protection).
There is a risk of fire spreading if these require-
ments are not observed.
A balanced flue without a duct must not be
routed through other installation rooms, as
there is a risk of fire spreading and mechanical
protection is not ensured.
Combustion air must not be drawn from chim-
Note
neys previously used to carry flue gases from
oil or solid fuel boilers.
Outside the duct, secure the balanced flue or
standard flue with spacer clips. These must
be placed at a minimum of 50 cm from the ap-
pliance connection and upstream/downstream
of diversions, to prevent the pipe joints being
pulled apart. Failure to observe this creates
the risk of poisoning caused by escaping flue
gas. Furthermore, damage to the appliance
may result.
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