6
2.3
Suitable flues and minimum flue sizes are as follows:-
a)
225mm x 225mm conventional brick flue.
b)
175mm diameter lined brick or stone flue.
c)
200mm diameter factory made insulated flue manufactured to BS4543.
d)
175mm diameter flue pipe. See BS6461 Part 1 for suitable materials.
e)
Single wall, twin wall or flexible flue liner with a minimum diameter of 125mm.
The materials to be used are stainless steel or aluminium as specified in BS715.
f)
A properly constructed precast concrete or clay flue system conforming to
BS1289 Part 1 or 2. This system is only suitable when the conditions stated in section
2.2.3 are met.
2.3.1
It should be noted that, as with many appliances, sharp bends or horizontal runs
in metal flues at the top of the system can be a cause of problems in these types of
installation.
2.4
The minimum effective height of the flue must be 3m.
2.5
The flue must not be used for any other appliance or application.
2.6
Any chimney damper or restrictor should be removed. If removal is not possible,
they must be secured in the open position.
2.7
If the appliance is intended to be installed to a chimney which was previously
used for solid fuel, the flue must be swept clean prior to installation. All flues should be
inspected for soundness and freedom from blockages.
2.8
If the fireplace opening is an underfloor draught type, it must be sealed to stop
any draughts.
2.9
The appliance must be mounted behind a non-combustible hearth (n.b
conglomerate marble hearths are considered as non-combustible). The appliance can
be fitted to a purpose made proprietary class “O” 150°C surround. The hearth material
must be at least 12mm thick. The periphery of the hearth (or fender) should be at least
50mm above floor level to discourage the placing of carpets or rugs over it.
The surface of the hearth must be sufficiently flat to enable the bottom of the front
surround, the burner bracket and the bottom front cover casting to be aligned
horizontally. Any excessive unevenness (uneven tiles, Cotswold stone, etc.) should be
rectified.
The appliance must not stand on combustible
materials or carpets.
The appliance must not be fitted directly against
a combustible wall.
If the appliance is to be fitted
against a wall with combustible cladding, the cladding
must be removed from the area covered by the outer
surround
(see figure 3). We suggest that the actual
surround is used as a template to mark the area for
combustible cladding removal.
2.10
The minimum distance from the outside edge
of the front surround to a corner wall or other
projection which extends further forward than the
front of the appliance at either side is shown in
figure 3.
2.11
The front face of the fireplace should be
reasonably flat over the area covered by the convection
box top and side flange seals to ensure good sealing.
These faces should be made good if necessary.
The fireplace floor should be reasonably flat to ensure
that a good seal with the convection box can be made.
2.12
The minimum height from the top surface of the hearth to the underside of any
shelf made from wood or other combustible materials is as follows:-
•
For a shelf up to 150mm deep
Minimum height = 750mm.
•
For a shelf deeper than 150mm
750mm + 12.5mm for every 25mm depth over 150mm.
Fig 3 Front dimensions & side clearance to projections
