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904L Mi-FLEX 80mm x 1m CUT LENGTH (36Z-80-1)

Discover National Flues' high-quality 904L Mi-FLEX 80mm x 1m CUT LENGTH, a state-of-the-art flexible flue liner designed to reline masonry chimneys. Made from premium 904L stainless steel, this double-skinned, multi-fuel compatible flue liner is both HETAS approved and CE certified, ensuring optimum safety and performance for a variety of fuels. Perfect for both modern and traditional chimney installations, our product stands as the ideal choice for customers seeking robustness and efficiency.
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At a Glance

    Premium 904L stainless steel construction with double-skinned design
    Smooth inner and convoluted outer layer, each 0.105mm thick
    Quattrolock seam for enhanced durability and secure bonding
    Suitable for multiple fuels including gas, oil, coal, coke, cured dry logs, cured dry peat, and approved smokeless
    HETAS approved and CE certified for industry-leading safety standards
    Lifetime manufacturer warranty when installed with Screw-Fix accessories
Delivery Information +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Tuesday, July 1st. This is based on current delivery times for this product. Delivery for products not in our warehouses can be delayed because of third party carriers. If you need a stove, or other bulky product, to be delivered by a specific time in the next 7 days then please give us a call. We can sometimes reduce longer lead times if we pay the carrier £25 for express delivery. Visit our Shipping Information page for more information.

Warranty & Returns +

All our products come with warranties and you can read in our blog about they types and terms and conditions for warranties. Mi-Flex flue liner, for example, comes with a lifetime guarantee. Give us a call if you want to know about a specific warranty. Returns for damaged items are covered by insurance; non-damaged returns incur return delivery costs.

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We will match any price, like-for-like, on a retail basis. Give us a call if you find it cheaper and want to buy from us.

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Price Match Guarantee: If you find the same product cheaper within 48 hours, we’ll match it and refund the difference.

Free Delivery Over £100: Orders over £100 are free delivery (call us if delivery is required outside the mainland UK).

“I saved 20% on my purchase compared to other retailers. Exceptional service!” – Jane D.

Have Questions?
Phone: 01670 206999
Email: [email protected]

The 904L Mi-FLEX 80mm x 1m CUT LENGTH is an industry-leading double-skinned flexible flue liner, engineered to reline masonry chimneys. Crafted from premium 904L grade stainless steel, it features both a smooth inner and convoluted outer skin, each with a thickness of 0.105mm. This advanced construction includes a quattrolock seam, ensuring the highest level of strength and durability.

Approved by HETAS and CE certified, this flue liner is suitable for a variety of fuels including gas, oil, coal, coke, cured dry logs, cured dry peat, and approved smokeless fuels. Installation is straightforward: simply start from the top of the chimney with the arrows pointing upwards to ensure correct gas flow. Maintenance is minimal but essential, with an annual sweep recommended for chimneys serving solid fuel appliances.

SKU: 36Z-80-1

Technical Specifications
SKU36Z-80-1
Material904L Stainless Steel (Inner & Outer 0.105mm)
DesignDouble-skinned with smooth inner and convoluted outer surfaces
SeamQuattrolock
Fuel CompatibilityGas, Oil, Coal, Coke, Cured Dry Logs, Cured Dry Peat, Approved Smokeless Fuels
ApprovalsHETAS, CE
ManufacturerMi-Flues Ltd
WarrantyLifetime (with Screw-Fix accessories)
InstallationTop-down installation with proper arrow alignment for optimal gas flow
- Begin installation at the top of the chimney with the arrows pointing upward to ensure correct gas flow. - Use a piece of string attached to the nose cone to guide the liner down carefully. - Verify that the chimney pot is in good condition; if using a suspended cowl with a deteriorated pot, removal may be necessary before installation. - It is recommended to schedule an annual sweep for chimneys serving solid fuel appliances to maintain peak performance and safety.

The 904L Mi-FLEX flue liner is suitable for burning gas, oil, coal, coke, cured dry logs, cured dry peat, and approved smokeless fuels.

The flue liner should be installed from the top of the chimney with the arrows pointing upwards to ensure proper gas flow. Use a piece of string attached to the Nose Cone to pull the liner down the chimney.

Yes, the 904L Mi-FLEX flue liner is both HETAS and CE approved.

The flue liner features both a smooth inner and convoluted outer skin, each with a thickness of 0.105mm.

It is recommended that chimneys serving solid fuel appliances be swept and maintained at least once a year.

If you are not using a suspended cowl and your chimney pot is in poor condition, it should be removed before installing the flue liner.

The flue liner is constructed from 904L grade stainless steel using a single strip of steel that is bent at 180 degrees and then the seam is folded in four planes to create a quattrolock seal.

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