3
Chimney Terminations
All chimneys should terminate above the roof level in
accordance with current Building Regulations and as
outlined in BS 6461: Part 1 and BS 7566 Parts 1 to 4.
However well designed, constructed and positioned the
satisfactory performance of a flue can be adversely
affected by the downdraught caused by adjacent tall
buildings and tress or even nearby hills. These deflect the
wind creating a zone of high pressure over the terminal
causing it to blow directly down the chimney flue.
A suitable anti-downdraught terminal such as the
Marcone
will usually effectively combat low pressure down-blow but
no known cowl is likely to prevent downdraught due to a
high pressure zone.
NOTE: ADVISE THE USER TO ENSURE CHIMNEY
FLUES ARE THOROUGHLY SWEPT AT A MINIMUM OF
12 MONTHLY INTERVALS AFTER THE APPLIANCE IS
COMMISSIONED.
Preparation of a Builders Recess Opening
The appliance and recess, hearth and chimney flue
installation should be in accordance with the relevant
recommendations of the British Codes of Practice BS 8303,
BS 6461 Part 1 and BS 7566 Parts 1 to 4, with the boiler
and heating installation complying with BS 5449 Part 1.
The boiler section must also be installed in accordance with
the bye laws of the Local Water Undertaking, Regulations
for the Electrical Equipment of Buildings- published by the
Institute of Electrical Engineers, and any relevant
requirements of the Local Authority.
The appliance can be installed in a non-combustible recess
in which the hearth must be level and together with the
adjacent walls, conform to the current Building Regulations.
A rectangular recess is required not less than 975mm wide
and not less than 375mm deep from the face of the recess
and 1320mm minimum height for a top flue outlet version.
Holes will be required in one or both sides of the pipework.
The clearance between the appliance and any combustible
material must be maintained as indicated in Figs 1a, 1b, 2a,
2b and 3.
A permanent unobstructed air vent is required, having a
minimum effective area of 83cm2 and communicating
directly to outside air or an adjacent room which itself has
a permanent air vent direct to outside air.
Effect of Extractor Fan
Avoid if possible, the installation of an extractor fan in the
same room as the appliance or the room where the
permanent vent is located. Compensating extra air inlets
must be introduced to the capacity of the fan when fitted.
Flue Layout
In Fig. 1a, 1b and 2a the stove is installed in an existing
recess directly below the chimney flue. The exit end of the
flue pipe must extend a minimum of 150mm into the
overhanging brickwork. Any cavities or pockets above the
register plate should as far as possible be filled, with the
flue pipe extended into the throat of the chimney. If a flue
liner or insulated chimney is used, the diameter should not
be less than 175mm in both cases. In Fig. 3 the stove is
connected to an existing flue with a length of flue pipe.
Square bends and horizontal runs must not be used and a
cleaning door included at every bend.
Fig. 2b shows a back flue outlet into a chimney brickwork.
NOTE: EXTENDED LENGTHS OF HORIZONTAL
PIPEWORK MUST BE AVOIDED AND SHALL NOT
EXCEED 150mm.
NOTE: WHATEVER METHOD OF INSTALLATION IS
UTILISED, AIR MUST NOT BE ALLOWED TO ENTER
THE CHIMNEY EXCEPT THROUGH THE STOVE AND
ALL JOINTS MUST BE AIR-TIGHT. IF THE CHIMNEY IS
UNLINED AND THERE IS ANY DOUBT ABOUT ITS
CONDITION. IT SHOULD BE LINED IN ACCORDANCE
WITH THE CURRENT BUILDING REGULATIONS.
PROVISION MUST ALWAYS BE MADE FOR SWEEPING
THE CHIMNEY.
IMPORTANT: CEMENT PIPES AND FITTINGS MUST
NOT BE USED WITHIN 2m OF THE STOVE OUTLET.
CHIMNEYS OF PLAIN PIPE ARE NOT RECOMMENDED
BUT CERTAIN PROPRIETARY MAKES OF INSULATED
CHIMNEY ARE SUITABLE.
AIR SUPPLY
