There are several basic flue systems available for Rayburns. Click on flue type for more information.

SOLID FUEL - USING A MASONRY CHIMNEY

A properly designed and installed flue system is essential, to enable a Rayburn to operate safely and efficiently.

Whenever possible a masonry (stone or brick) chimney should be used, as this will probably have sufficient height and be more in character with the rest of the property.

Any chimney which is to be used for a Rayburn should first be swept and its condition checked.

The chimney must be lined internally with an acid resistant material, such as jointed clay or ceramic pipes. Property built since 1965 should already have these linings, but earlier built chimneys will almost certainly not be so protected. This is very important with appliances burning wood, where tar or creosote may be deposited with the consequent risk of a chimney fire.

There are several methods of lining an existing chimney, such as :-

• Use a proprietary cast in-situ. method. This is carried out by specialist contractors.
• Lower down or break into the chimney and fit sectional clay or ceramic linings
• Fit a flexible stainless steel lining of a special grade, suitable for multi-fuel appliances. This will be of a double skin construction.

For aesthetic reasons, the initial flue pipe used to connect between the Rayburn and the chimney lining, should be of black, vitreous-enamel, cast-iron pipe. If absolutely necessary, the flue can exit horizontally from the rear of the Rayburn, but should not extend more than about 150mm, i.e. the thickness of a single brick.

Three typical methods of chimney connections.

When the main chimney is reached it is usually necessary to increase the diameter by at least one size. The number of bends must be kept to a minimum and must be no sharper than 45 degrees, allowing the flue to rise as vertically as possible. An ordinary decorative or plain, terra cotta pot should be sufficient to terminate the flue, although for use in areas of adverse wind conditions there are several proprietary anti-downdraught cowls available.

Typical anti-downdraught cowls/pots :

'Marcone'

'O-H'

In situations where the flue draught can be particularly strong, for example with extra tall chimneys, it may be necessary to fit an automatic draught stabilizer, to prevent over-burning in windy conditions.

It is essential to have convenient access for sweeping or cleaning the fluepipe as well as the main chimney. This can be achieved by :-

• All bends or fittings having their own removable covers.
• The main chimney having a cleaning chamber with soot door which must be of the double skin variety.

If wood is to be burned, it is a good idea to incorporate a condensation receptacle at the base of the chimney. This can ideally be sited so as to accommodate the cleaning access as well, as shown above.

All joints in the flue and chimney system must be properly sealed and air tight, using rope and fire-cement.

At-a-glance guide to flue sizes Minimum required for Solid and Multi fuel Rayburns

This information is given for general guidance only. Reference must be made to the current Building Regulations and Codes of Practice, together with the appropriate product Installation Instructions.

SOLID FUEL - USING A PRE-FABRICATED FLUE SYSTEM

A properly designed and installed flue system is essential, to enable a Rayburn to operate safely and efficiently.

This method of providing a flue is useful when there is no conventional chimney present, as there are options to take the flue externally up the side of the property, or even pass it up through internal rooms suitably boxed in and protected. It may also be painted externally, so as to harmonize with the property.

It is better known as a Pre-fabricated, factory-insulated, twin wall system, of which there are several proprietary makes.

It is important to choose the right material for the flue system and to carefully follow the manufacturers instructions for installation, particularly in respect of clearances to adjacent combustible materials. Flues serving multi-fuel appliances can develop extremely high temperatures in the event of a chimney fire and must therefore be constructed of a suitable type of material. This will normally have its inner and outer skins manufactured of high grade stainless steel, with a ceramic material as insulation. The number of bends must be kept to a minimum and must be no sharper than 45 degrees, allowing the flue to rise as vertically as possible. If several bends have to be used then the diameter of the flue must be increased. All joints in the flue and chimney system must be properly sealed and air tight For aesthetic reasons, the initial flue pipe used to connect between the Rayburn and the main flue system, should be of black, vitreous-enamelled, cast-iron pipe.. For solid fuel Rayburns, there is normally a minimum flue height required of 5.5 metres, but the height and termination point must be determined by compliance with current legislation, taking into account the possible affect of surrounding buildings or obstructions.

At-a-glance guide to flue sizes Minimum required for Solid and Multi fuel Rayburns

This information is given for general guidance only. Reference must be made to the current Building Regulations and Codes of Practice, together with the appropriate product Installation Instructions.

GAS - USING A MASONRY CHIMNEY

A properly designed and installed flue system is essential, to enable a Rayburn to operate safely and efficiently.

Whenever possible a masonry (stone or brick) chimney should be used, as this will probably have sufficient height and be more in character with the rest of the property.

Any chimney which is to be used for a Rayburn should first be swept and its condition checked.

The chimney must be lined internally with an acid resistant material, such as jointed clay pipes. Property built since 1965 should already have these linings, but earlier built chimneys will almost certainly not be so protected.

There are two convenient methods of lining an existing chimney :- Introduce a flexible stainless steel lining. In this case, if the chimney diameter is excessive or is in an exposed or external position, it is good practice to fill in the space between the lining and the masonry with an insulation material such as vermiculite. This will help to keep the flue gases warm and prevent condensation. Use a proprietary cast in-situ. method. This is carried out by specialist contractors. Even when a chimney is lined with existing clay linings, these may be of too larger diameter and the flue gases may cool down and produce condensation. In such cases it is beneficial to additionally fit a flexible lining. In all situations, the flue must terminate with an approved gas cowl.

For aesthetic reasons, the initial flue pipe used to connect between adjacent to the Rayburn and the chimney lining, should be of black, vitreous-enamelled pipe, preferably cast iron. There must be a vertical length of 600mm, measured from the top of the Rayburn flue connection, before a bend is introduced. The number of bends must be kept to a minimum and must be no sharper than 45 degrees, allowing the flue to rise as vertically as possible. For most Rayburns, there is normally a minimum flue height required of 3 metres, but the height and termination point must be determined by compliance with current legislation, taking into account the possible affect of surrounding buildings or obstructions.

At-a-glance guide to minimum flue pipe diameter required for gas-fired Rayburns

This information is given for general guidance only. Reference must be made to the current Building Regulations and Codes of Practice, together with the appropriate product Installation Instructions.

GAS - USING A PRE-FABRICATED FLUE SYSTEM

A properly designed and installed flue system is essential, to enable a Rayburn to operate safely and efficiently.

This method of providing a flue is useful when there is no conventional chimney present, as there are options to take the flue externally up the side of the property, or even pass it up through internal rooms suitably boxed in and protected. It may also be painted externally, so as to harmonize with the property.

It is better known as a Pre-fabricated, factory-insulated, twin wall system, of which there are several proprietary makes.

It is important to choose the right material for the flue system and to carefully follow the manufacturers instructions for installation.

Air, is used for the insulation material between the inner and outer skins in some flue systems, but generally these are only suitable for internal flue runs. If the run is external or prone to adverse weather conditions, then a stainless steel pipe system should be used, which incorporates additional insulation material.

For aesthetic reasons, the initial flue pipe adjacent to the Rayburn, should be of black, vitreous-enamelled cast-iron pipe, transposing to the twin-walled pipe system before the flue leaves the kitchen area. There must be a vertical length of 600mm, measured from the top of the Rayburn flue connection, before a bend is introduced. The number of bends must be kept to a minimum and must be no sharper than 45 degrees, allowing the flue to rise as vertically as possible. For most Rayburns, there is normally a minimum flue height required of 3 metres, but the height and termination point must be determined by compliance with current legislation, taking into account the possible affect of surrounding buildings or obstructions. The flue must terminate with an approved gas cowl. It is possible to utilize a roof ridge vent with those models requiring a flue size of 125mm or less.

At-a-glance guide to minimum flue pipe diameter required for gas-fired Rayburns

This information is given for general guidance only. Reference must be made to the current Building Regulations and Codes of Practice, together with the appropriate product Installation Instructions.

POWER FLUES

A power flue can be useful for installing a Rayburn into a situation where no conventional chimney exists, or perhaps where the cooker cannot be sited as a balanced flue AGAinst an outside wall. Power flue options are available for the natural gas fired Rayburn 400 (both natural gas and LPG). The flue pipe can exit from either the left or right hand side of the Rayburn at low level using a 54mm diameter stainless steel tube, with a range of push-fit fittings, clips and flexible insulation.

There are a number of important points to be considered as to where the flue should be terminated so as to comply with current legislation and good practice. Places to be avoided are: Underneath windows. Close to doorways. Adjacent to obstructions or protruding buildings. Discharging into carports or garages, alleyways or thoroughfares.

A basic flue installation pack is supplied with each cooker.

The pipe may be run via any convenient route, including as shown, up to a maximum of 5 metres in length and incorporating a total of five bends, either 90 or 45 degree angle.

A stainless steel flue terminal unit housing a low voltage extractor fan is fitted on the outside wall. This does not normally require any additional terminal guard.