INSTALLER’S GUIDE
Page 7
Fig. 4 Fireplace with fireback to BS1251
Requirements for use with kit 617K
2.4
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.
•
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 BS715. 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 1806. This system is only suitable if the conditions stated in section 2.3 are met.
2.5
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.
2.6
The flue must not be used for any other appliance or application.
2.7
Any chimney damper or restrictor should be removed. If removal is not possible,
they must be secured in the open position.
