FAQ

  • What type of flue do I need?

    A: If you do not have a suitable chimney then you will need to provide a chimney system for your appliance in line with current regulations. For wood, solid fuel and some decorative gas fires this will need to be a chimney suitable for Class 1 appliances, as flue gas temperatures can become very high.

  • Why Line Chimneys?

    A: Chimneys are lined for a number of safety related reasons. While new chimneys may require relining, systems that predate 1965 will often require a modern lining solution for the following reasons:

    1. The flue may have lost integrity and can leak smoke into rooms or other parts of the building.

    2. Condensates or tar can seep through chimney walls causing staining, inside or outside of the building.

    3. Lining with insulation included improves the operation of appliance and flue (particularity important when the chimney is on an external wall).

    4. Defective flue systems may be eroded and rough. This will cause frictional resistance to the flow of the gases resulting in poor updraught.

    5. Large flues (over 200mm) particularly ones containing voids may affect appliance performance. Some appliance manufacturers specify smaller flues for efficient operation.

  • Do I need planning permission?

    A: No, not normally. Installation of a stove and/or new flue system would not usually have anything to do with the local planning authority. If your property is a Listed Building then permission may or may not be required depending on the visual aspect. If you intend your new flue pipework to run up the outside of an external wall then depending on the position (e.g. side or front of house) you may need to check with the local Planning Department.

    Fitting, altering or replacing an external flue, chimney, or soil and vent pipe is normally considered to be permitted development, not requiring planning consent, if the conditions outlined below are met:

    Flues on the rear or side elevation of the building are allowed to a maximum of one metre above the highest part of the roof.

    If the building is listed or in a designated area even if you enjoy permitted development rights it is advisable to check with your local planning authority before a flue is fitted.

    In a designated area the flue should not be fitted on the principal or side elevation that fronts a highway.

  • We have no chimney but would like a stove?

    A: You don't have to have a brick chimney stack in your property in order to have a wood burning or multi fuel stove. It's possible to provide for the chimney requirement using a stainless steel pre-fabricated twin wall insulated chimney such as MF. Our MF is a universal multi-fuel and multifunctional chimney suitable for internal and external applications. It can be used for high temperature applications, but also because of the integral silicone sealing ring, it can be applied to condensing and positive pressure installations. It is suitable for use at continuous operating temperatures of 450°C for negative pressure applications and 200°C for positive pressure applications.

  • What should I look for when selecting the correct flue system?

    A: The CE Marks means that the flue has been tested to pan-European quality and performance standards. In the UK we also have British Standards for the construction and performance of all kinds of flues and flue linings, which broadly coincide with European Standard but, there is an important exception in that, there is an appendix to the European Standard EN 1856-1 (for flues serving Class 1 Appliances) designated BSEN1856-1. In part this is because UK Building Regulation requires flues passing through floors and ceilings to have a minimum clearance from the surface of the flue to combustible material and still have 30mins fire resistance. This achieved by means a special fire-stop which allows air to pass freely but closes and seals in the event of a fire. This must be the same fire-stop used in the BSEN1856-1 test. HETAS publish a guide for solid fuel appliances and flue and flue linings.

  • Can I fit the Flue System?

    A: The short answer to this question is yes you can. However, upon connecting an appliance to flue systems, if you are not HETAS registered, you will need to get your Local Authority Building Control Department to sign off the work to say that the installation complies with building regulations.

    Connection to an appliance which is not connected to the fuel supply should be carried out by a competent person. Flue Trader Limited recommends the use of HETAS approved installers for solid fuel applications. However, connection to an appliance that is connected to the fuel supply must be carried out by a Gas Safe (Gas) or OFTEC (Oil) registered installer.

    You can find a certified HETAS approved installer by going onto their website www.hetas.co.uk, for more details. Flue Trader Limited can suggest using an installer in your area upon request.

  • How much would it cost to line my chimney?

    A: For an average two storey property with an 8m chimney using a 150mm diameter flexible grade 316 liner – £825.00 + vat excluding access equipment

  • How much would it cost to have a twin wall chimney?

    A: For an average two storey property with an 8m chimney, rising on the external cable wall connecting from appliance to termination, using a 150mm diameter MF twin wall system – £1,150.00 + vat excluding access equipment

  • Do we need to have the chimney swept before the new installation?

    A: Definitely. This will ensure that the chimney is clean and not blocked from many years of the build-up of burnt deposits and possible birds’ nests etc. Your sweep should also be able to tell you the general condition with any necessary recommendations required.

  • How often should I have my chimney swept?

    A: HETAS recommends the use of an approved chimney sweep who is a member of The Association of Professional and Independent Chimney Sweeps, The Guild of Master Chimney Sweeps or The National Association of Chimney Sweeps who can give an inspection and sweeping certificate. A chimney or flue liner should be swept at least once a year when burning authorised smokeless fuels and at least twice a year when burning wood or bituminous coal. A list of HETAS Approved Sweeps can be found by clicking the ‘Find a Chimney Sweep’ search tab at the top of each page of the website

  • Are our products approved?

    A: All of our flue and chimney systems are HETAS Approved. The products we use are approved and CE marked to EN 1856-1 and manufactured under a quality assurance scheme, administered by British Standards in accordance with BS EN 9001: 2008

  • Once installed what is the Lifetime expectancy?

    A: Under normal operating conditions and providing the system is installed to the manufactures recommendations, whether it is a twin wall, single wall or flexible type system, installed by a HETAS certified personnel flue systems should last the lifetime of the appliance if not longer depending on the use.

  • Are notice plates required for hearths and flues?

    A: Where a hearth, fireplace (including a flue box), flue or chimney is provided or extended (including cases where a flue is provided as part of the refurbishment work), information essential to the correct application and use of these facilities should be permanently posted near to be appliance. Notice plates should be robust, indelibly marked and securely fixed in an unobtrusive but obvious position within the building.

  • What diameter multi fuel flue liner do I need?

    A: The diameter of the chimney liner required depends on many things including the type of appliance and fuel/s which you are using, current building regulations, the fireplace opening size and the chimney stack height. Never reduce and down size from the appliance.

  • Do I have to get inspection hatches by law?

    A: No. There is no legal duty on the consumer to have inspection hatches installed. However, there is a long-standing legal duty on gas engineers to be able to examine the flue to ensure it is safe whenever they work on your boiler. In the majority of cases this will be only be possible though the installation of inspection hatches. If gas engineers cannot examine the flue along its length they will advise you that the installation is ‘At Risk’ and will seek your permission to turn it off.

  • My flue also runs through neighbouring property, will the engineer need to access their properties to inspect the flue?

    A: Where the flue also passes through a neighbouring property the engineer should take all reasonable steps to ensure overall flue integrity. This will involve making enquiries with the occupants of the neighbouring property. In these situations and on the basis of checks of the boiler and the chimney/flue system in the property containing the boiler are all satisfactory, reasonable steps need to be taken to gain access to adjacent property to check overall chimney/flue system integrity. Gaining access to adjacent property will normally require the full assistance and co-operation of others to achieve e.g. Housing Associations, Social Landlords and neighbours etc.

  • What Regulations do I adhere too?

    A: The construction and application of chimneys and flues is covered by UK Building Regulations in conjunction with the relevant European and British Standards. Whilst these differ in emphasis, they all mandate the safe application of the chimney no matter where and how used. These Regulations and Standards dictate the minimum criteria which it is necessary to apply if the chimney or flue is to function safely and correctly. Building control approval is necessary for building new chimneys and in some cases for relining old chimneys particularly if some alteration or change of the heating appliance occurs.

  • Do I need extra room ventilation?

    A: Normally for most houses in the UK no extra ventilation is required when installing a stove rated at 5kW or less. For stoves above 5 kW a permanent air vent connected to the outside is required in the same room as the appliance. The size of the vent would normally need to be a minimum of 550mm² per kW above 5 kW. e.g. a stove rated at 7kW would need 550mm² x 2 = 1100mm². That would be a square opening approx. 33mm x 33mm.

    The purpose of providing extra ventilation for larger stoves is simply to ensure there is enough oxygen being supplied into the room to allow proper combustion in the stove.

    Note: The requirements regarding ventilation have been updated in the most recent version of the Regulations and are now based on the air permeability of the house. Houses built after 2008 should have an air permeability test result which you should be able to see at the time of purchase. In practical terms what is likely is that the newest houses will be very air tight, i.e. no gaps under doors etc., and so will have a greater requirement for extra ventilation. If the test result shows an air permeability of less than 5m³/h.m² then in these cases the requirement is 550mm² per kW, regardless of the total kW output of the stove. If in doubt please ask us for advice and we'll do our best to help. It is unlikely that a property built before 2008 will have air permeability less than that so the normal procedure will apply to 99% of properties i.e. only stoves greater than 5kW need a vent.

  • Who will install my stove?

    A: It is highly recommended that a professional HETAS registered installer is used to fit your stove and flue system. A list of installers can be found on the HETAS Website where you can find the nearest fitter in your area. The installer will be able to certify and commission your appliance, they will ensure your appliance fits to the Building Regulations and is suitable for purpose. If you were to fit the stove yourself you will have to follow the Building Regulations and have it checked and certified. We do not recommend you fit the appliance yourself; an installer has much experience and will be able to fit your stove quicker and often using safer techniques.

  • What is a Smoke Control Area?

    A:  Under the Clean Air Act local authorities may declare the whole or part of the district of the authority to be a smoke control area. It is an offence to emit smoke from a chimney of a building, from a furnace or from any fixed boiler if located in a designated smoke control area. It is also an offence to acquire an "unauthorised fuel" for use within a smoke control area unless it is used in an "exempt" appliance ("exempted" from the controls which generally apply in the smoke control area). The current maximum level of fine is £1,000 for each offence.

    Exempt appliances are appliances (ovens, wood burners and stoves) which have been exempted by Statutory Instruments (Orders) under the Clean Air Act 1993 or Clean Air (Northern Ireland) Order 1981. These have passed tests to confirm that they are capable of burning an unauthorised or inherently smoky solid fuel without emitting smoke

  • Should a CO alarm have been fitted when my appliance was installed?

    A: Yes, from 2010 it is a legal requirement that a CO alarm must be fitted in the same room that the appliance has been installed in.

  • Do I obtain any documentation once my installation is complete?

    A: Yes, upon completion of your installation your installer will issue a HETAS certificate of compliance which shows that your appliance has been installed to the correct standard of practice and in accordance with Building Regulations.

  • Are there any specific chimney and termination heights?

    A: The minimum chimney height recommended for minimum performance of wood burning and multi fuel appliances is 4.5 m from the top of the appliance to the top of the chimney. It is best to position the chimney, so that it goes straight up as near to the roof ridge as possible. The diagram in Document J, shows the minimum flue discharge heights and positions for all wood burning and multi fuel applications. In some cases, particularly when chimneys are towards the bottom of a sloping roof or at the eaves, it may be necessary to increase the chimney height above these minimum mandatory requirements. The reason for this is to clear pressure zones created by wind hitting the roof and nearby structures, like trees, which may interfere with the up draught required by the appliance or fire. The maximum freestanding stack height above the roof for a traditional masonry chimney is 5.4 times the narrowest horizontal part of the chimney. In the case of stainless steel system chimneys, the manufacturer’s installation instructions should be consulted; however in most cases it will be around 1.5 metres. This measurement is taken from the last point where the chimney stack passes the through or past the edge of the roof up to the chimney capping or termination. Tall chimneys may need bracing, always consult the manufacturer for advice.

    The law relating to the flueing of biomass boiler installation is complex with many areas of overlapping legislation.

    If the locality of the installation is a smoke control area the minimum requirements are that all boilers installed in the area must be exempted appliances under the Clean Air Act 1993 and the height of the chimney serving any biomass boiler capable of burning more than 45.4 kg an hour of fuel must be approved by the Local Authority.

    Larger boilers may require a permit under the Environmental Permitting Regulations and depending upon the fuel used may fall within the requirements of the Waste Incineration Directive.

    The Clean Air Act Memorandum determines the final chimney height for gas and oil appliance (es). This publication does not mention bio-fuels and needs to be updated in line with modern installations. There are other publications for ‘guidance’ such as IGE/UP/10, LAQM & Environmental Agency, which state the flue termination must be 2m above a building for boilers under 1MW and 3m above a building for boiler plant rated above 1000kw.

    The radius is 5U within the height of any building should be taken into account according to the Clean Air Act Memorandum but the ‘Guidance notes for biomass boiler Installations’ from Environmental Agency refers to: distance to taller adjacent structure must be 5 x height of total stack from ground level.

    Copies of European and British Standards can be obtained from:

    British Standards Institution, 389 Chiswick High Road, Chiswick, London. W4 4AL. Tel: 0208 996 9000

    BS EN 483:2000 Gas-fired central heating boilers. Type C boilers of nominal heat input not exceeding 70 kW. Replaced BS 5258: Pt 1; 1986

    BS EN 509:2000 Decorative fuel-effect gas appliances. Replaced BS 5258: Pt 12; 1990.

    BS 715: 2005 Specification for metal flue boxes for gas-fired appliances not exceeding 20kW.

    BS 1251: 1987 Specification for open fireplace components.

    BS EN 1443: 2003 Chimneys – general requirements.

    BS EN 1457: 2012 Chimneys, Clay/Ceramic flue liners. Requirements and test methods. Replaced BS 1457: 1999

    BS EN 1806: 2006 Chimneys Clay/ceramic flue blocks for single wall chimneys. Requirements and test methods

    BS EN 1856 - 1: 2009 Chimneys. Requirements for metal chimneys. System chimney products. Replaced BS 4543: Pts 2 and 3 & BS 715: 1993 BS EN 1856 - 2: 2009 Chimneys. Requirements for metal chimneys. Metal liners and connecting metal flue pipes Replaced BS 715: 1993

    BS EN 1857: 2010 Chimneys - Components. Concrete flue liners. Replaced BS 7435:Pts 1-2

    BS EN 1858 2008: Chimneys, Components, Concrete flue blocks. Replaced BS1289: Pt 1

    BS EN 1859 2009 Chimneys. Metal chimneys. Test methods. Replaced BS 4543: Pt 1:1990

    BS 5871: 2005 Specification for installation of gas fires, convector heaters, fire/back boilers and decorative fuel effect gas appliances

    Pt1: Gas fires, convector heaters and fire/back boilers.

    Pt2: Inset live fuel effect gas fires of heat input not exceeding 15kW.

    Pt3: Decorative fuel effect gas appliances of heat input not exceeding 15kW.

    BS 5440: 2008 Installation of flues and ventilation for gas appliances of rated input not exceeding 70 kW.

    Pt1: 2008 Specification for installation of flues.

    Pt2: 2008 Specification for installation of ventilation for gas appliances.

    BS 15287-1 Open Appliances, BS15287-2 Room-Sealed Appliances Installation of chimneys and flues for domestic appliances burning solid fuel (including wood and peat).

    Code of practice for masonry chimneys and flue pipes

    BS 6999:1989 Specification for vitreous-enamelled low carbon steel flue pipes.

    BS 7977-1:2009 Specification for safety and rational use of energy of domestic gas appliances.Radiant/convectors Replaced BS 5258: Pts 5 and 16.

    BS 7977-2:2009 Specification for safety and rational use of energy of domestic gas appliances. Combined appliances. Gas fire/back boiler. Replaced BS 5258: Part 8.

    BS EN 15287-1: 2007 Chimneys. Design, installation and commissioning of chimneys. Chimneys for non-room-sealed appliances.

    BS EN 12446 : 2011 Chimneys. Components. Concrete outer wall elements.

    BS EN 13063-1: 2005 Chimneys. System chimneys with clay/ceramic flue liners. Requirements and test methods for sootfire resistance.

    BS EN 13063-2: 2005 Chimneys. System chimneys with clay/ceramic flue liners. Requirements and test methods under wet conditions.

    BS EN 13069: 2005 Chimneys. Clay/ceramic outer walls for system chimneys. Requirements and test methods BS EN 13216 : 2004 Chimneys. Test methods for system chimneys. Replaced BS 4543 BS EN 13502 : 2002 Chimneys. Requirements and test methods for clay/ceramic flue terminals. Replaced BS 1181:1999.

    BS EN 50291-1: 2010. Electrical apparatus for the detection of carbon monoxide in domestic premises. Test methods and performance requirements.

  • Do you ship your products to non-UK destinations (ie. Europe/Worldwide)?

    A: No. At present we only ship our products to UK addresses.