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• The chimney has been swept and tested prior to
installation.
• The proximity of all combustible materials to the
intended stove installation conforms to the minimum
requirements outlined within this handbook as well
as local, national and European building regulations,
whichever is the greater. A combustible material is
anything which can burn once it gets hot enough
and includes skirting boards, wooden fire surrounds,
wooden mantles, wallpaper, fabrics and floor
coverings. Remember these materials could be con-
cealed behind other materials which on the surface
may appear to be non-combustible, for example, stud
partitioned walls. It also worth noting that heat-
resistant materials will eventually combust should they
inadvertently reach the required higher combustion
temperatures.
Important Minimum Distances For This Stove
The minimum distances to combustible materials for
the HF357i-B Precision Inset Boiler are as follows:
Top (eg mantel shelf)
200 mm
Sides (eg fire surround) 100 mm
APPLIANCE INSTALLATION:
GENERAL GUIDELINES
Please refer specifically to current building regulations
which apply to your country or region. Adopt
whichever provides the highest / safest margin.
Asbestos
This stove does not contain Asbestos. However, check
that there is no possibility of disturbing any asbestos-
based materials during its installation. You may
intend removing an older appliance prior to installing
your new stove, and you should be aware that the
old appliance or installation could incorporate heat
protective asbestos sheet or other asbestos-based
materials – if in doubt seek guidance at
www.hse.
gov.uk/asbestos
– do not underestimate the potential
health hazards of handling Asbestos.
The Hearth
The hearth should be made of solid non-combustible
material, set on a firm and level base and should be at
least 125mm (5”) thick. This can include the
thickness of any non-combustible floor under the
hearth or non-combustible decorative surface. It must
be capable of supporting the weight of the stove
(when loaded) and boiler (with water add 10kg) along
with any attached flexible flue liner which may bear
down on the stove. This hearth must conform to local
building regulations which may vary from country to
country.
In England and Wales there is a minimum requirement
for the hearth to project 500mm (20”) in front of any
brick or stone recess and 150mm (6”) at each side of
the recess. The hearth should extend by a minimum
of 225mm (9”) from the front of the stove (which
includes the edge of the ash lip). As a general rule it is
best to extend the hearth to at least 75mm (3”)
beyond the furthest out-swing of the stove door if
possible to avoid any potential live ash held on the
inset door falling on to combustible flooring or floor
coverings. If the top of the hearth and any
combustible floor coverings are level with each other
then a retaining fender should be fitted to warn
occupants of the hearth area. Alternatively, a 28mm
(1.1”) change in level provided by a decorative non-
combustible material such as stone, marble, granite,
ceramic tiles etc could be used.
Please note that some materials, such as marble, may
not be suitable when used in a single sheet. This may
prove problematic if, for example, the inset stove is
being installed within an existing fire surround which
features a one-piece back panel which the inset stove
is intended to sit inside. Non-combustible fire
surrounds intended for use with solid fuel open fires
and stoves feature smaller panels pieced together
which allow space for expansion when hot. Your stove
dealer or installer should be able to advise you about
the suitability of an existing fire surround.
The ‘Fireplace’
The stove must be sited within a brick or stone fire-
place recess. It is unsafe to use this inset stove as a
free-standing stove.
The fireplace side and rear walls should be at least
75mm thick and made of non-combustible brick or
stone. Any gaps at the back and sides of the stove
and the fireplace aperture should be filled with non-
combustible insulation material such as rockwool or
vermiculite. This will not only improve the efficiency of
the stove but also help avoid the potential build-up of
combustible soot along the sides – this is an especially
important requirement if you are
not
using a flue liner.
Inset Boiler Stove Fireplace Opening
Your Precision Inset Boiler stove has been designed
to fit relatively easily within a 16” x 22” (400mm x
550mm) standard builders’ fire opening.
• Redundant back boilers or ‘Baxi’ type ash pits and
air intakes ideally should be removed, filled and
levelled.
• Existing fireplaces and hearths must be made of
non-combustible materials as well as be suitable for
use with a solid fuel stove. For example the hearth
and backplate ideally should be ‘slabbed’ with
concrete and any decorative surface finishes, such as
marble, should be ‘tiled’ to allow for heat expansion.
• Ensure that any existing fire surround or fireplace
back plate you propose to re-use or leave in position is
secure and that any air gaps between it and the back
wall are sealed, particularly around the actual fireplace
opening and the backplate interface. It is important
for safety reasons that this seal is air tight.
