3. Installation Requirements – Page 11
3.3
Chimneys & Flues
1)
A flue system (lined throughout its
length) must be provided to evacuate the
flue products of combustion from the
boiler. Reference should be made to the
building regulations and BS 5440:1. and
the flue system efficiency should be
checked in accordance with BS5440.
2)
Ideally a flue should rise vertically and
any terminal or termination point shall be
positioned so that combustion products
can disperse safely at all times.
Therefore for practical purposes, the flue
should have the shortest possible run to
external atmosphere, with as near
vertical rise as possible, 90° bends
should be avoided. The terminal must be
at least above roof level and of a type
approved by British Gas.
3)
There must be at least 2.5m equivalent
of vertical flue from the boiler flue socket.
4)
Horizontal runs should be avoided,
however if a near horizontal flue run is
unavoidable, the total vertical height
necessary should be calculated in
accordance with BS 5440:1.
5)
If an existing chimney is used, ensure
that it is thoroughly swept before lining or
connecting the boiler. The liner must
have an internal diameter of 125mm and
be acceptable by British Gas.
6)
Care should be taken to avoid
condensation in the flue.
7)
Where a flue liner is necessary (use a
non-porous acid resistant type) slide the
liner into the chimney to finish at a height
of 547mm above the hearth level on
which the boiler will stand. Fit an
approved outlet terminal to the top of the
liner, seal and clamp as shown. A
sealing plate should also be fitted and
sealed to close off the base of the
chimney.
8)
In the case of a pre-lined chimney, it
must be connected to the socket of the
boiler flue hood with a length of liner.
9)
Where a chimney lined with a vitreous
enamelled flue liner is used, connect and
seal a short length of flexible liner into
the base of the flue, to finish at the
correct height above the hearth level.
10)
A precast concrete flue block system
may be used provided the cross
sectional area is at least 129cm sq. and
the precautions outlined in BS 5440:1
are observed.
Seal
Seal
Liner
Approved
Terminal
Cement
Seal
Sealing
Plate
Set Into
Chimney
362
Seal
Seal
Pre-lined
Flue
Liner
362
BB45011A
Fig. 10
Summary of Contents for Housewarmer 45
Page 17: ...4 Installation Page 17 ...
Page 25: ...8 Electrical Diagrams Page 25 ...
Page 34: ...Installation Page 7 ...
Page 35: ...Installation Page 8 ...
