Do I need my chimney lined?

There is a regulation that says your installer must satisfy themselves that the chimney is free from defects and suitable for its intended use. When he or she checks your chimney they may find that the only way to provide you with a compliant and safe installation is to line the chimney.
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Liner v No Liner

One of the most common questions asked on the HETAS Consumer Helpline is Do I need my chimney lined?

There is a regulation that says your installer must satisfy themselves that the chimney is free from defects and suitable for its intended use. When an installer checks your chimney they may find that the only way to provide you with a compliant and safe installation is to line the chimney. If there is any risk that the chimney could leak fumes in to the house they must line it with a suitable re-lining material. There are quite a few choices of system and the most popular is the flexible stainless steel type. It may be an essential part of your installation.

If any work undertaken on the chimney, including installation of a new liner, is done in conjunction with the installation of a heating appliance, then that work is a controlled service and must be undertaken by a competent person, such as a HETAS Registered Installer or approved by your Local Authority Building Control department.

Why line a chimney?

Chimneys are lined for a number of safety reasons. New chimneys may require relining to suit the fuel type being used (a gas flue liner may not be suitable for other fuels). Chimney systems that predate 1965 will often require a modern lining solution for the following reasons:

  • The flue may have lost integrity and can leak smoke into rooms or other part of the building
  • Condensates or tar can seep through chimney walls causing staining, inside or outside of the building
  • Lining with insulation included can improve the operation of the appliance and flue – particularity important when the chimney is situated on an external wall
  • Defective flue systems may be eroded and rough. Thus will cause frictional resistance to the flow of the gases resulting in poor up-draught
  • Large flues over 200mm, particularly ones containing voids, may affect appliance performance. Some appliance manufacturers specify smaller flues for efficient operation

BFCMA Guidance

The BFCMA has produced general guidance on the selection and installation of flues and chimneys for wood burning and multi fuel appliances in residential properties. Click here to view the guidance document. Always consult a HETAS Registered Installer prior to undertaking any solid fuel installation work.


The British Flue & Chimney Manufacturers’ Association is Britain’s only Trade Association for factory-made chimney products and works closely with HETAS, Government, public bodies and other organisations to further the interest of the chimney & flue industry. Click here to find out more about the BFCMA.


Search the HETAS Product list for suitable chimney systems and liners.

HETAS Ltd

HETAS, Severn House, Unit 5 Newtown Trading Estate, Green Lane, Tewkesbury, GL20 8HD