4.11 Flues.
1.
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 BS4543 Part 2.
175mm diameter flue pipe. See BS6461 Part 1 for suitable materials.
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
BS EN 1856 Part 1. 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.
A properly constructed precast concrete or clay flue system conforming to BS1289
or BS EN 1858. This system is only suitable if the conditions stated in section 4.10.3
are met.
2.
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 2m of 125mm dia. flue pipe.
3.
The flue must not be used for any other appliance or application.
4
.
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.
4.12 Propane appliances.
Propane gas appliances must not be installed in a room that is built entirely below
ground level (See BS 5871 Part 2).
©
Baxi Heating U.K. Limited 2011.
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INSTALLER GUIDE
