16
Part No. 5106463
Pre-Installation Requirements
Fig. 10
central heating systems for domestic
premises.
•
BS 7074: Pt.1:1989 Application, selection
and installation of expansion vessels and
ancillary equipment for sealed systems.
•
BS 7671 Requirements for electrical
installations. IEE wiring regulations 16th
edition.
•
Control of pollution (oil) regulations.
•
Local water undertakings bye-laws.
Chimney
Every Potterton boiler has a very high
efficiency and care must be taken to ensure
that the chimney is suitable.
Chimneys may have been already built and
completed before a choice of appliance has
been made. Alternatively, chimneys may
be installed to suit the particular appliance
chosen.
A factory made insulated chimney
complying with the requirement of BS4543
may be considered as an alternative to a
conventional structural chimney for both
new and existing buildings. A further
alternative may be a suitable form of
insulated flue pipe normally positioned on
a wall outside a building.
Capacity
The chimney or flue must have a cross-
sectional area throughout its whole length,
that is at least the area of the flue outlet of
the boiler and must be sealed at the boiler
with fire clay or other suitable compounds.
As few bends as possible should be used
and, where necessary, 135° bends are
recommended.
Height
The chimney or flue should be of sufficient
height to provide a minimum draught of
0.035" w.g. measured above the boiler.
Draught conditions that are excessive i.e.
above 0.16" w.g. due to chimney height or
location, should be controlled by means of
a draught stabiliser fitted to the chimney.
External Flues
All external flues of metal or other materials
should have cleaning facilities, and be well
insulated to maintain the correct draught
conditions.
