RAIS VISIO 1 Instructions For Installation, Use And Maintenance Manual Download

Page: 76 / 81

anual for Rais Visio 1, Visio 2 and Visio 3

Rev 7

February 2016

Chimney

For the stove to perform satisfactorily the chimney height must be sufficient to ensure an adequate draught
of approximately 15 Pa so as to clear the products of combustion and prevent smoke problems into the
room.

NOTE: A chimney height of not less than 4.5 metres measured vertically from the outlet of the stove to the
top of the chimney should be satisfactory. Alternatively the calculation procedure given in EN 13384-1 may
be used as the basis for deciding whether a particular chimney design will provide sufficient draught.

The outlet from the chimney should be above the roof of the building in accordance with the provisions of
Building Regulations Approved Document J.

If installation is into an existing chimney then it must be sound and have no cracks or other faults which
might allow fumes into the house. Older properties, especially, may have chimney faults or the cross
section may be too large i.e. more than 230 mm x 230 mm. Remedial action should be taken, if required,
seeking expert advice, if necessary. If it is found necessary to line the chimney then a flue liner suitable for
solid fuel must be used in accordance with Building Regulations Approved Document J.

Any existing chimney must be clear of obstruction and have been swept clean immediately before
installation of the stove. If the stove is fitted in place of an open fire then the chimney should be swept one
month after installation to clear any soot falls which may have occurred due to the difference in combustion
between the stove and the open fire.

If there is no existing chimney then either a prefabricated block chimney in accordance with Building
Regulations Approved Document J or a twin walled insulated stainless steel flue to BS 4543 can be used.
These chimneys must be fitted in accordance with the manufacturer’s instructions and Building
Regulations.

A single wall metal fluepipe is suitable for connecting the stove to the chimney but is not suitable for using
for the complete chimney. The chimney and connecting fluepipe must have a minimum diameter of 150 mm
and its dimension should be not less than the size of the outlet socket of the stove.

Any bend in the chimney or connecting fluepipe should not exceed 45°.  90° bends should not be used.

Combustible material should not be located where the heat dissipating through the walls of fireplaces or
flues could ignite it. Therefore when installing the stove in the presence of combustible materials due
account must be taken of the guidance on the separation of combustible material given in Building
Regulations Approved Document J and also in these stove instructions.

If it is found that there is excessive draught in the chimney then a draught stabiliser should be fitted. Fitting
of a draught stabiliser will affect the requirement for the permanent air supply into the room in which the
stove is fitted in accordance with Approved Document J (see also combustion air supply).

Adequate provision e.g. easily accessible soot door or doors must be provided for sweeping the chimney
and connecting fluepipe where it is not intended for the chimney to be swept through the appliance, also to
permit visual checks on the integrity of the flue when the appliance is serviced.

Hearth

The hearth should be able to accommodate the weight of the stove and its chimney if the chimney is not
independently supported. The weight of the stove is indicated in the brochure.

The stove should always be installed on a non-combustible hearth of a size and construction that is in
accordance with the provisions of the current Building Regulations Approved Document J.

The clearance distances to combustible material beneath, surrounding or upon the hearth and walls
adjacent to the hearth should comply with the guidance on the separation of combustible material given in
Building Regulations Approved Document J and also in these stove instructions.

If the stove is to be installed on a combustible floor surface, it must be covered with a non-
combustible material at least 12mm thick, in accordance with Building Regulations