INSTALLER GUIDE
Page
8
3.6
The minimum height from the top of the hearth to the underside of any shelf
made from wood or other combustible materials is as follows (See also Graph 1).
•
For a shelf up to 150mm deep: minimum height = 818mm
•
For a shelf deeper than 150mm
818mm + 12.5mm for every 25mm shelf depth over 150mm.
3.7
Suitable flues and minimum flue sizes are as follows:-
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.
•
225mm x 225mm conventional brick flue.
•
175mm diameter lined brick or stone flue.
•
200mm diameter factory made insulated flue manufactured to BS 4543.
•
175mm diameter flue pipe. See BS 6461 Part 1 for suitable materials.
•
Single wall, twin wall or flexible flue liner with a minimum diameter of
125 mm. The materials to be used are stainless steel or aluminium as specified in
BS 715. The liner must be sealed to the surrounding area above the fireplace
opening and to the top of the chimney. An approved terminal must be fitted. Note:
The inner and outer convection box restrictor plates must be removed for liners
with a diameter of 125mm. For larger diameter liners removal of the restrictor
plates may be necessary depending on the results of the spillage test.
Graph 1. Combustible shelf clearances.
