Product Description

904 Stainless Steel Flue Liner Kit 1 – 6 Inch 150mm

Model: 904/904 Liner Kit 1 – 6 Inch

Install a complete flexible chimney-lining system with the 904 Stainless Steel Flue Liner Kit 1 in 150mm. This complete kit combines your selected continuous length of premium 904/904 flexible liner with the main components required for a typical chimney installation.

Both liner skins use high-grade 904L stainless steel. Therefore, this liner provides greater resistance to corrosive combustion deposits than a standard 316L liner. Its flexible, double-skinned construction makes it suitable for relining an existing masonry chimney.

The liner suits compatible appliances burning seasoned dry wood, gas, oil, coke, cured dry peat and approved low-sulphur solid fuel. However, always check the appliance instructions and current Building Regulations before selecting the liner grade and diameter.

What Is Included in Flue Liner Kit 1?

• Selected continuous length of 150mm 904/904 flexible flue liner
• 1 x liner nose cone
• 1 x top clamp
• 1 x top plate
• 1 x chimney identification plate
• 1 x inset rain cap
• 1 x equal vitreous-enamel pipe-to-flexible-liner adaptor

The kit includes the components required for a typical installation using a top plate, top clamp and inset rain cap. However, chimney designs vary. Therefore, ask your installer to confirm that Kit 1 suits your property before ordering.

904 Flue Liner Kit 1 Key Features

• Complete 150mm flexible flue liner installation kit
• 150mm internal flue diameter
• Also known as a 6-inch flue liner kit
• 904L-grade stainless-steel inner skin
• 904L-grade stainless-steel outer skin
• Double-skinned flexible construction
• Designed for relining suitable masonry chimneys
• Includes the main installation and termination components
• Suitable for compatible wood-burning and multifuel appliances
• Suitable for approved gas and oil installations
• Suitable for approved low-sulphur solid fuel
• Greater corrosion resistance than a standard 316L liner
• Smooth inner surface supports an efficient flue-gas path
• HETAS-listed flexible flue liner
• Manufacturer’s lifetime warranty on the liner, subject to conditions
• 10-year warranty on the supplied kit components, subject to conditions
• Choice of made-to-measure liner lengths

150mm 904 Flue Liner Specification

• Product type: flexible chimney liner installation kit
• Kit type: Kit 1
• 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 folded 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: 904/904 Liner Kit 1 – 6 Inch

Suitable Fuels

• Seasoned dry logs
• Approved low-sulphur or smokeless solid fuel
• Coke
• Cured dry peat
• Gas
• Oil

Always use a fuel permitted by the appliance manufacturer. In addition, avoid wet or unseasoned wood because it can create more soot, tar and corrosive condensate.

The 904L construction makes this liner a strong choice for compatible multifuel appliances and installations where greater resistance to corrosive deposits is required.

Why Choose a 904/904 Flue Liner?

A 904/904 liner uses 904L-grade stainless steel for both the inner and outer skins. This high-grade material provides excellent resistance to the acidic deposits produced by some solid fuels.

As a result, a 904L flue liner may provide a better long-term option for frequently used multifuel appliances. It may also suit installations where smokeless mineral fuel forms part of the approved fuel mix.

However, you must still use the correct fuel and maintain the chimney regularly. Always follow the appliance and liner manufacturer’s instructions.

Is a 150mm Flue Liner Suitable for My Stove?

A 150mm liner is commonly used with wood-burning, multifuel and open-fire installations. However, the correct diameter depends on the appliance, fireplace opening and complete chimney design.

Therefore, always check the appliance manufacturer’s instructions, current Building Regulations and HETAS guidance before ordering.

Never reduce the flue below the size permitted by the appliance manufacturer. A competent installer should also confirm that the 150mm liner can pass through the complete masonry chimney.

How Does Kit 1 Terminate the Chimney?

The top plate sits over the chimney opening and helps close the area around the liner. Next, the top clamp supports the liner at the correct height.

The inset rain cap connects to the liner and helps reduce direct rain entry. Meanwhile, the included identification plate records important information about the completed chimney system.

At the bottom, the equal adaptor connects a compatible vitreous-enamel stove pipe to the flexible chimney liner. Always check the connection sizes before installation.

904L Flue Liner Construction

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

The manufacturer forms the liner from a single strip of stainless steel. The strip bends through 180 degrees, while the seam folds across four planes to create a Quattrolock seal.

As a result, the liner combines a smooth internal flue route with a strong and flexible outer structure.

Before Installation

• Confirm that 150mm is the correct diameter for the appliance
• Confirm that a 904L liner suits the intended fuel
• Measure the complete chimney route before ordering
• Allow enough liner for the top and bottom connections
• Check that the liner can pass through the chimney
• Consider testing the route with a short section of 150mm liner
• Have the chimney swept and inspected
• Check the chimney stack and masonry condition
• Confirm that the Kit 1 terminal arrangement suits the chimney
• Check that every included component has the correct connection size
• Check the direction arrows printed on 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 can pass through the complete chimney route.
3. Secure a suitable rope to the included 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 sharply pulling, crushing or twisting the liner.
9. Remove the nose cone when the liner reaches the correct position.
10. Fit the top plate and support the liner with the top clamp.
11. Fit the inset rain cap and complete the lower adaptor connection.
12. Finally, complete and securely fit the chimney identification plate.

Always follow the manufacturer’s instructions and current Building Regulations. Where appropriate, use a HETAS-registered installer. A suitably qualified Gas Safe registered engineer must complete any gas installation.

Manufacturer’s Lifetime Liner Warranty

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

The warranty must be registered. Failure to complete the required warranty registration may reduce the liner warranty to one year.

The lifetime warranty applies to the 904/904 flexible flue liner. The supplied kit components carry a 10-year manufacturer’s warranty, subject to the relevant terms and conditions.

Correct installation, approved components, suitable fuel and regular maintenance may affect the warranty.

Complete the MI Flues lifetime warranty registration form after installation.

You may also 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 and diameter
• Installed liner length

Cleaning and Maintenance

Arrange regular chimney sweeping and inspection after installation. A chimney serving a solid-fuel appliance should be swept as often as the appliance, fuel and level 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 received 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
• Complete installation kit
• Help selecting compatible flue components
• Warranty registration support
• Support for homeowners and professional installers
• Secure online ordering

If you need help selecting the correct kit, call SNH Tradecentre on 01843 842727.

Important Information Before Ordering