Chimney Requirements
These appliance's must not be fitted into a chimney serving another heating appliance. It is most
important that there is no obstruction in the flue or chimney. Please ensure that any existing
chimney is clear of obstruction and swept clean immediately before installation of the new stove.
Where the chimney is believed to have served an open fire previously it is possible that the higher
flue gas temperature from a closed appliance may loosen deposits that were previously firmly
adhered, with the consequent risk of flue blockage. It is therefore recommended that the chimney
be swept a second time within a month of regular use after installation.
A flue draught minimum of 12 Pascals to a maximum 18 Pascals is required for satisfactory
appliance performance. A properly built masonry or factory constructed chimney (with a minimum
vertical height of 5 metres) should ensure a consistent draught (draw). 45° bends can be used in
the flue run (maximum of four bends) you will need to add an extra 1 metre of vertical flue height
for each bend.
The flue draught should be checked under fire at high output and if it exceeds the recommended
maximum, a draught stabiliser must be fitted so that the rate of burning can be controlled, and to
prevent over firing (See section “Warning Notes”). If you have any doubts about the suitability of
your chimney, consult your local dealer/stockist or engineer. If your flue draft is below the minimum
recommendation then it may be necessary to increase the vertical chimney height, add additional
flue insulation or possibly add a special cowl to the top of the chimney (e.g. anti down draft cowl to
eliminate wind induced down draft).
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. Remedial action should be
taken, if required, seeking expert advice, if necessary. 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.
If there is no existing chimney then either a prefabricated block chimney in accordance with
Building Regulations Approved Document J or a twin walled insulated stainless steel flue to BS
1856-1 can be used. These chimneys must be fitted in accordance with the manufacturer’s
instructions and Building Regulations.
If a flexible liner is required the liner diameter must not be less than 6”.
Any bend in the chimney or connecting fluepipe should not exceed 45°. 90° bends are not
permitted. . For top flue installations it is possible to sweep through the appliance by removing the
internal baffle however it is recommended that you provide adequate access (e.g. easily accessible
soot door). For rear flue connection we recommend the use of a tee section, this should be capped
at the bottom to catch soot and debris. All joints in the connection between the stove and the
chimney must be made gastight using fire cement and where necessary fire-proof rope infill.
Please refer to British Standards BS EN 15287-1:2007 design, installation and
commissioning of chimneys for additional requirements.
GB12A Issue 2
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