Fitting To Metal Flue Boxes - Flavel Windsor Installation, Maintenance & User Instructions

Table A - Installation Depth Requirements for a Flavel Windsor Plus / Stirling
Plus being installed into a brick built chimney, requiring 12.0 litres of debris
collection volume (figure 2)
Opening Width (mm)
330 (minimum opening width)
340
350
360
370
380
390
400
410
420
430
440 (maximum opening width)135
For example, if the appliance was to be fitted into a 400mm wide opening, the
depth required would be 135mm. See figure 2 below for explanatory diagram.
Fig. 2
1.7 FITTING TO PRE-FABRICATED TWIN WALL METAL FLUE BOXES
The appliance may be fitted to twin wall metal flue boxes conforming to the
constructional requirements of BS 715 / BS EN 1856-2, (for example the Selkirk
LFE 175 box). The box must have a minimum flue diameter of 125mm internal
and minimum internal dimensions of 185mm deep by 580mm high by 400mm
wide. There are no maximum dimensional requirements for the box. The top face
of the box must be insulated with a minimum thickness of 50mm of
non-combustible mineral wool insulation or similar material. The flue box
must stand on a non-combustible base of minimum thickness 12mm.
Minimum Depth Required (mm)
152
149
146
144
142
139
137
135
135
135
135
Opening Width ( e.g. 400mm)
8
Depth Required
(e.g. 135mm
minimum)