4.10.1
The flue must conform to BS 5440: Part
1 in design and installation.
The flue, measured from the bottom of the
fireplace opening to the bottom of the terminal,
shall be not less than 3m in actual vertical
height. When calculated in accordance with BS
5440: Part 1 Annex A, the minimum
equivalent
height of the flue shall be 2.0m of 125mm dia.
flue pipe.
4.10.2
The flue must be clear of any
obstruction and its base must be clear of debris.
4.10.3
The flue must be completely sealed so
that combustion products do not come into
contact with combustible materials outside the
chimney.
4.10.4
The flue must serve only one fireplace.
4.10.5
Proprietary terminals must comply with
BS 715 or BS 1289. Any terminal or
termination must be positioned in accordance
with BS 5440 Part 1 to ensure that the products
of combustion can be safely dispersed into the
outside atmosphere. Where the appliance is connected to an unlined brick chimney it is
generally unnecessary for the chimney pot to be replaced or for a terminal to be fitted
unless the flue has a diameter smaller than 170mm.
4.11
If the fireplace opening is an underfloor draught type, it must be sealed to stop
any draughts.
4.12
The flue spigot and any spigot extension must be capable of passing through the
closure plate by at least 25mm with a minimum clearance of 50mm between its open
end and the nearest obstruction.
There must also be a minimum clearance of 165mm between the back of the closure
plate and the back of the catchment space.
The catchment space below the flue spigot must extend at least 250mm downwards
measured from the bottom of the flue spigot.
See figure 2.
4.13
The front of the fireplace should be flat over an area sufficient to ensure a good
seal with the closure plate. The flat surface should extend for a height equal to that of
the closure plate plus 20mm and for a width equal to that of the closure plate plus
40mm.
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INSTALLER GUIDE
Figure 2 Fireplace catchment
space.