an installation where the finished flue height
would be less than 4.5 metres. Failure to satisfy
this requirement could result in the installation
failing the commissioning and spillage tests
outlined elsewhere in this handbook (see
pages 35 to 38) as well as invalidate your
extended Hi-Flame Warranty.
This stove features optional top or rear
125mm (5”) diameter flue outlets and as a
Defra Approved Smoke Exempted Appliance
the connecting flue pipe and stainless steel
flue liner can also of 125mm diameter
(subject to Building Regulations)
Under no circumstances should the stove’s
125mm diameter flue be reduced in any part
of the flue system as this could cause a build
up of dangerous carbon monoxide (CO) gas.
Although it is possible to sweep the flue
system through this stove once the baffle
plates have been removed (see page 32) it is
recommended that there should be at least
one additional cleaning access point within
either the connecting flue pipe, twin wall
chimney system or where there are bends.
Flexible Flue Liner
Hi-Flame strongly recommend fitting a flue
liner when installing this stove within an
existing chimney for the following reasons:
• A flue liner is a major ‘quantifiable’ component
which provides a consistent flue diameter and
regular inner surface and as such will minimise
interference to the updraught and help improve
it. When back-filled with vermiculite insulation
a liner will keep flue gases as hot as possible
which will help improve the stove’s operation
and minimise the amount of smoke produced.
• An existing chimney could leak smoke,
fumes and potentially dangerous ‘invisible’
carbon monoxide (CO) into other parts of the
building. Condensation or creosote tar,
associated with burning wood, could
eventually seep through the chimney walls,
particularly if they are made of old or porous
brick and / or are jointed with lime mortar,
eventually causing unsightly stains on
decorative coverings.
• Stoves work best with the correct draught.
Pre-1965 chimneys which have been built
for open fires have larger (and often irregular
shaped) voids than those best suited for a
modern stove and this could reduce the
effectiveness of the flue draught by making
the flue too cold and difficult to warm. This
is a particular problem if the chimney breast
is on an outside wall and / or is subject to a
strong prevailing wind.
• Many houses built since 1965 with clay
or concrete chimney liners suffer from these
being poorly installed, either through being
fitted the wrong way up or not receiving an
appropriate application of mortar to make
a complete seal on each of the many joints.
Even though the chimney may not be
particularly old, this could still potentially
allow smoke and fumes or unsightly
condensation stains to leak through.
Chimney Terminal
The existing chimney pot or terminal must be
suitable for stove installation and should not
restrict the smoke and fumes from the stove. It
must provide at least the same outlet area as
the flue pipe. It may be that your existing
chimney terminal has been replaced with a
ventilating terminal if the fireplace has been
closed off at some point. Your installer will be
able to advise you about the appropriate
specification of any new cowl or terminal. A
cowl has the additional advantage of
limiting rain entering the flue system which
could cause the inside of the stove to rust
when it is not being used, particularly during
the long periods outside the heating season. it
will also help to reduce odours from moisture
build-up in the chimney system, through
infrequent burning, as this dries out.
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