Product Description

904/904 Solid Fuel Stainless Steel Flue Liner 6 Inch 150mm

Model: 6 Inch 904/904 Flue Liner

Re-line a suitable masonry chimney with this premium 150mm 904/904 stainless-steel flexible flue liner. Both skins use highly corrosion-resistant 904L-grade stainless steel. Therefore, this liner provides extra protection for demanding wood-burning and multifuel installations.

The double-skinned construction creates a strong and continuous flue route inside an existing chimney. In addition, the smooth inner skin helps flue gases travel upwards efficiently.

This liner suits compatible appliances burning cured dry wood, approved smokeless coal, coke, gas, oil or cured dry peat. However, you must check the appliance instructions before choosing the liner diameter and length.

904/904 Flue Liner Key Features

• 150mm internal flue diameter
• Also known as a 6-inch flexible flue liner
• 904L stainless-steel inner skin
• 904L stainless-steel outer skin
• Double-skinned flexible construction
• Designed for relining suitable masonry chimneys
• Suitable for compatible wood-burning and multifuel appliances
• Suitable for approved gas and oil applications
• Suitable for approved smokeless fuel applications
• Excellent resistance to corrosive flue deposits
• Smooth inner skin supports an efficient flue-gas path
• Convoluted outer skin provides flexibility and strength
• Quattrolock folded seam construction
• HETAS-listed liner
• Manufacturer’s lifetime warranty, subject to registration and conditions
• Supplied in the selected made-to-measure length

150mm 904 Flue Liner Specification

• Product type: flexible chimney flue liner
• Nominal internal diameter: 150mm
• Imperial size: 6 inches
• Inner skin material: 904L-grade stainless steel
• Outer skin material: 904L-grade stainless steel
• Inner skin thickness: 0.105mm
• Outer skin thickness: 0.105mm
• Construction: double skinned
• Seam design: four-plane Quattrolock seal
• Application: relining an existing masonry chimney
• Pressure class: N1
• Temperature class: T450
• Declared classification: EN 1856-2 T450 N1 D V3 L50012 G
• Model: 6 Inch 904/904 Flue Liner

Suitable Fuels

• Cured dry logs
• Approved smokeless coal
• Coke, where permitted by the appliance manufacturer
• Cured dry peat
• Gas
• Oil

Do not burn ordinary house coal unless the appliance and complete flue system specifically permit it. Always follow the appliance manufacturer’s fuel instructions.

Use properly seasoned wood with a suitable moisture content. Wet or unseasoned wood can create more soot, tar and corrosive condensate inside the chimney.

Is a 150mm Flue Liner Suitable for My Stove?

A 150mm liner is a common choice for wood-burning and multifuel appliances with a 150mm flue outlet. It may also be required where an appliance does not have approval for a smaller 125mm flue.

However, you should not choose the diameter from the stove outlet alone. Always check the appliance instructions, current Building Regulations and HETAS guidance before ordering.

A competent installer should also confirm that a 150mm liner will pass through the full length of the existing masonry chimney.

904L Flue Liner Construction

The smooth inner skin uses 0.105mm 904L-grade stainless steel. Meanwhile, the convoluted outer skin also uses 0.105mm 904L stainless steel.

The manufacturer forms the liner from a single strip of stainless steel. It bends the material through 180 degrees and folds the seam across four planes. As a result, the Quattrolock construction creates a strong yet flexible flue liner.

Why Choose a 904/904 Flue Liner?

904L stainless steel offers greater resistance to corrosion than standard 316L stainless steel. Therefore, it is a strong choice for demanding installations and appliances that regularly burn approved smokeless fuels.

The 904/904 construction uses premium 904L stainless steel on both skins. As a result, it provides extra protection throughout the complete liner rather than only on the inner surface.

A 904-grade liner may cost more than a 316-grade alternative. However, its increased corrosion resistance can make it the better long-term choice for suitable multifuel installations.

Before Installation

• Confirm that 150mm is the correct diameter for the appliance
• Confirm that the liner suits the intended appliance and fuel
• Measure the complete chimney route before ordering
• Allow enough length for the required top and bottom connections
• Check that the liner can pass through the chimney
• Consider testing the route with a short 150mm section
• Have the chimney swept and inspected
• Check that the chimney pot and stack remain in sound condition
• Select compatible adaptors, terminals and support components
• Check the direction arrows printed on the liner
• Use a compatible nose cone to help guide the liner

Flue Liner Installation Guidance

A suitably competent installer should fit the liner from the top of the chimney. The directional arrows printed on the liner must point upwards in the direction of the flue gases.

1. First, sweep and inspect the existing masonry chimney.
2. Next, confirm that the liner will pass through the complete chimney route.
3. Secure a suitable rope to a compatible liner nose cone.
4. Attach the nose cone securely to the bottom end of the liner.
5. Check that the arrows point away from the nose cone and towards the chimney top.
6. Carefully feed the liner down from the top of the chimney.
7. At the same time, a second person should guide the rope from below.
8. Avoid sharp pulling, crushing or twisting the liner.
9. Once the liner reaches the correct position, remove the nose cone.
10. Finally, connect and support the liner with approved compatible components.

Always follow the manufacturer’s instructions and current Building Regulations. Where appropriate, use a HETAS-registered installer. Gas appliances must be installed by a suitably qualified Gas Safe registered engineer.

What Is Included?

• 1 x selected continuous length of 150mm 904/904 flexible flue liner

Please note: Adaptors, clamps, plates, cowls, nose cones and other installation components are not included unless the selected product option states otherwise.

Manufacturer’s Lifetime Warranty

This 904/904 flexible flue liner carries a manufacturer’s lifetime warranty, subject to registration and the manufacturer’s terms and conditions.

The warranty may depend on correct product selection, installation by a competent person, use of approved compatible components, permitted fuel use and regular maintenance.

To register the warranty, email darren@snhuk.co.uk with the following information:

• Customer’s name and installation address
• Name and address of the HETAS-registered installer
• Installation date
• Appliance make and model
• Fuel type
• Liner grade
• Liner diameter
• Installed liner length

You can also complete the MI Flues lifetime warranty registration form.

For a copy of the warranty terms and conditions, email sarahf@snhuk.co.uk.

Keep your SNH Tradecentre invoice and installation records. The manufacturer may request this information if you make a warranty claim.

Cleaning and Maintenance

Arrange regular chimney sweeping and inspection after installation. Chimneys serving solid-fuel appliances should be swept as often as the appliance, fuel and frequency of use require.

However, the chimney should normally be swept at least once each year. Some installations may require more frequent cleaning. Always follow the appliance manufacturer’s instructions and the advice of a qualified chimney professional.

Why Buy from SNH Tradecentre?

SNH Tradecentre is an independent plumbing and heating merchant based in Birchington, Kent. We supply flue products to homeowners, stove installers and trade customers across the UK.

In addition, we work closely with MI Flues to provide product support and process flue-liner orders quickly. This close relationship helps us dispatch many available orders on the same working day when they arrive before the relevant cut-off time.

• Experienced UK plumbing and heating merchant
• Close working relationship with MI Flues
• Fast processing of made-to-measure liner orders
• Same-day dispatch available on many orders, subject to stock and cut-off times
• Help selecting compatible liner components
• Warranty registration support
• Support for homeowners and professional installers
• Secure online ordering

If you need help selecting the correct liner or installation components, call SNH Tradecentre on 01843 842727.

Important Information Before Ordering