Worcester Greenstyle Hanbury 4 Installation, Servicing And User Instructions Manual page 17

INSTALLATION
CHIMNEY
In order for the stove to perform satisfactorily the chimney height
must be sufficient to ensure an adequate draught of approximately
15 Pa so as to clear the products of combustion and prevent
smoke problems into the room.
NOTE: A chimney height of not less than 4.5 meters measured
vertically from the outlet of the stove to the top of the chimney
should be satisfactory. Alternatively the calculation procedure
given in EN 13384-1 may be used as the basis for deciding
whether a particular chimney design will provide sufficient
draught. BS EN 15287-1:2007 gives additional details.
The outlet from the chimney should be above the roof of the
building in accordance with the provisions of Building Regulations
Approved Document J.
If installation is into an existing chimney then it must be sound and
have no cracks or other faults which might allow fumes into the
house. Older properties, especially, may have chimney faults or
the cross section may be too large i.e. more than 230 mm x 230
mm. Should remedial action be required, expert advice should be
sought. If it is found necessary to line the chimney then a flue liner
suitable for solid fuel must be used in accordance with Building
Regulations Approved Document J.
Any existing chimney must be clear of obstruction and have been
swept clean immediately before installation of the stove. If the
stove is fitted in place of an open fire then the chimney should be
swept one month after installation to clear any soot falls which
may have occurred due to the difference in combustion between
the stove and the open fire.
If there is no existing chimney then any new system must be to
the designation described above and in accordance with Building
Regulations Approved Document J.
A single wall metal fluepipe is suitable for connecting the stove to
the chimney but is not suitable for use as the complete chimney.
The chimney and connecting fluepipe must have a minimum
diameter of 125mm and its dimension should be not less than the
size of the outlet socket of the stove.
Any bend in the chimney or connecting fluepipe should not
exceed 45°, 90° bends should not be used.
Combustible material should not be located where the heat
dissipating through the walls of fireplaces or flues could ignite it.
Therefore when installing the stove in the presence of combustible
materials due account must be taken of the guidance on the
separation of combustible material given in Building Regulations
Approved Document J and also in these stove instructions. If it
is found that there is excessive draught in the chimney then a
draught stabilizer should be fitted. Fitting of a draught stabilizer
will affect the requirement for the permanent air supply into the
room in which the stove is fitted in accordance with Approved
Document J (see also combustion air supply).
Adequate provision e.g. easily accessible soot door or doors must
be provided for sweeping the chimney and connecting fluepipe
where it is not intended for the chimney to be swept through the
appliance.
6720819898 A 05/2016
This stove may be connected with a factory built or masonry
chimney with a minimum diameter of 125mm. If you are using
a factory built chimney, it must comply with BS EN 1856-1:2003
standard. It is very important that it is installed according to the
manufacturer's specifications.
If you are using a masonry chimney, it is important that it be built
in compliance with the specifications contained in Document J.
The interior diameter of the chimney flue must be identical to the
stove smoke exhaust. A flue which is too small may cause draught
problems, while a large flue promotes rapid cooling of the gas,
and hence the build-up of creosote and the risk of chimney fires.
Note that it is the chimney and not the stove which creates the
draught effect; the stove's performance is directly dependent on
an adequate draught from the chimney.
The following points are important for the installation of the
chimney:
• It must rise above the roof at least 0.9m from the uppermost
point of contact.
• The chimney must exceed any part of the building or other
obstruction within a 3.04m distance by a height of 0.6m.
Installation of an interior chimney is always preferable to an
exterior chimney. Indeed, the interior chimney will, by definition,
be hotter than an exterior chimney, being heated up by the
ambient air in the house. Therefore the gas which circulates will
cool more slowly, thus reducing the build-up of creosote and the
risk of chimney fires. The draught caused by the tendency for hot
air to rise will be increased with an interior chimney.
Using a fire screen at the extremity of the chimney requires
regular inspection in order to ensure that it is not obstructed
thus blocking the draught, and it should be cleaned when used
regularly. Exterior chimney should be double or triple wall.
CONNECTION TO CHIMNEY
Stoves may have a choice of either a rear or top flue gas
connector that allows connection to either a masonry chimney
or a prefabricated factory-made insulated metal chimney in
accordance with their instructions.
HEATING IN-BETWEEN WINTER SEASONS
Heating the stove, when the outside temperatures are higher, the
flue gases may not be able to escape completely and this may
lead to disturbances in the chimney draught, especially if the
temperatures are rising suddenly. The stove has to be charged
with less wood and then primary air has to be increased so that
the wood can burn down faster (with visible flames) and thus the
chimney flue can stabilize.
REGULAR CLEANING
It is important that the appliance, flue gas connector and chimney
are regularly cleaned and checked for any possible blockages
prior to re-lighting after a prolonged shut down.
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