Ultraflex Basics Pack: 150mm (6") 904 Grade Steel Flue Liner Kit

Our UltraFlex Liner packs contain everything you will need to complete your installation. However you like to work, we have a pack for it.

Contained within the Basics Pack is:

1 x Ultra Flex Liner

1 x Standard Adaptor

1 x Pot Hanger Rain Cap

The Ultraflex Flexible Chimney Liner is a high-quality stainless steel flue liner designed for lining existing masonry or brick chimneys when installing a wood burning, multi-fuel, gas or oil appliance. Manufactured in the UK and produced to high industry standards, these liners provide a reliable and durable solution for improving chimney performance and ensuring safe operation of your heating appliance.

Constructed from twin-wall stainless steel, Ultraflex liners are available in 316/316 grade and 904/904 grade options to suit different fuel types and installation requirements. The twin-lined construction uses a robust stainless steel inner and outer layer with a triple-lock design, providing excellent durability, flexibility and resistance to corrosion. This strong construction also helps the liner resist crushing during installation while maintaining long-term structural integrity within the chimney.

The 316 grade liner is a popular choice for installations primarily burning seasoned wood, gas or oil. It offers strong resistance to corrosion and is designed for reliable everyday use with solid fuel appliances. The liner is capable of operating at temperatures of up to 600°C for solid fuel and 250°C for gas or oil appliances, ensuring safe performance under normal operating conditions.

For more demanding installations, the 904 grade liner provides enhanced durability and fuel compatibility. This premium grade stainless steel liner is suitable for a wider range of fuels including seasoned wood, gas, oil, coke, peat and smokeless fuels, making it ideal for multi-fuel appliances or heavier usage. Its higher resistance to corrosion and robust construction help extend the lifespan of the chimney system, particularly where smokeless fuels are used.

All Ultraflex flexible liners are HETAS approved and manufactured to meet recognised standards including BS EN 1856-2, ensuring they comply with strict safety and performance requirements. They are also designed to withstand extreme thermal shock conditions of up to 1000°C for short periods, providing additional protection in the unlikely event of a chimney fire.

Designed specifically for lining existing chimney stacks, the flexible structure allows the liner to be installed through bends and offsets commonly found within masonry chimneys. Various diameters and lengths are available to suit different appliances and chimney sizes, with liners supplied in lengths of up to 40 metres to accommodate a wide range of installations.

Ultraflex liners also come with a lifetime warranty (subject to conditions), providing additional peace of mind and confidence in the product’s quality and longevity.

Whether you are installing a new stove or upgrading an existing chimney system, the Ultraflex 316 or 904 grade flexible chimney liner provides a dependable, high-performance solution designed to deliver safe and efficient flue operation for many years to come.