Installation and Operating Instructions Reference: Casttec Firebox INSET version 5 January 2011
YOUR CHIMNEY: by becoming warm, makes the gas inside it rise, pulling fresh air into the stove to make it work. It must:
! Generate a draught in use of at least 12Pa (0.05ins wg)
! Be capable of withstanding the temperatures generated.
! Be incapable of leaking fumes into the dwelling
This will commonly be achieved by it:
! Being at least 5m high.
! Terminating at least 1m above any roof ridge.
! Having an internal cross-section not less than 0.018m² (e.g. 150mm diameter) and never more than 0.14m² (e.g. 375 x 375mm)
! Being free from even the slightest crack or source of leakage.
! Having no bends sharper than 45º.
! Being entirely free of obstructions and swept by a qualified chimney sweep.
! Being connected only to this one appliance.
! Being of thick masonry or otherwise adequately insulated.
! Conforming to local building regulations.
Special rules apply where the flue passes through timber, thatch or other vulnerable materials- take specialist advice.
Although it is possible to access the chimney through the fire with the throat plate removed, fit hatches to provide access if needed.
AIR SUPPLY: Your stove needs air to breathe - there must be a permanent fresh air supply into the room in which it is installed equal
to about 550mm² (e.g. 23mm square). This can often be provided by air naturally leaking into the building (it is commonly accepted
that this alone can suffice for appliances <5kW) but in any case of doubt, fit a purpose-made air vent. An extractor fan, or another fuelusing appliance, even in a different room, can remove this air.
LOCATION:
To prevent the risk of fire, the location into which your Stove is fitted must always:
• Have no combustible materials (such as a wooden surround) within 250mm of the stove sides or 400mm above
• Be made of materials able to continuously withstand 250ºC
• Even outside these distances take care in locating vulnerable materials such soft furnishings, decorations and other
flammable materials.
CHIMNEY SWEEPING:
Although it is often possible to sweep the chimney through the fire with the baffle plate removed, consider fitting cleaning hatches to
provide access if needed.
FITTING:
The stove can fit straight into a standard fireplace (Fig 2) conforming to BS1251 & BS8303, which will:
• Have an opening width (A) of between 400 and 420mm,
• An opening height (B) of between 540 and 560mm,
• A flat area (C) extending 70mm around the opening
• Have a heat-resistant hearth extending at least 300mm (D), without obstructions to prevent the door opening.
• Have the chair brick removed.
• Where thin slabs of mineral material (marble, limestone etc.) are used to face a fireplace, we recommend using separate panels, as
shown, to allow for differential expansion.)
• In the case of fixing the stove directly to a flue pipe, a cast iron spigot 6” diameter flue converter can be purchased
separately which fits to the stove via two bolts (Fig 10). This can be reduced down to fit a 5” flue pipe via a reducing ring if
needed.
• Position the stove into the fireplace opening, ensuring that the rope seal on the rear of the stove forms an absolutely airtight seal
against the fireplace. In some cases it may be necessary to knock-out part of the old fireback.
• Position the clamping bracket to the base of the hearth ensuring that it overlaps the rear inside lip at the back of the stove (Fig 3)
Secure the stove with a securing bolt into the hearth through the hole in the base of the clamping bracket (Fig 3) and two securing
bolts into the bottom front of the opening (Fig 4). It is not necessary to fill any small gap behind the appliance – larger gaps can be
filled with rubble, vermiculite granules or mineral fibre.
(Fig 2)