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300MM (12 Inch) Flue Liner - Premium Gas & Oil Flue System | National Flues

Discover National Flues' top-of-the-line 300mm (12 inch) flue liner, designed for both gas and oil systems. Our premium MI-Flex and Gas FLEX range includes essential components like top and bottom fixings, terminals, accessories, and register plates, ensuring a complete and efficient flue system installation.

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StovesPremium Stoves
FireplacesStunning Fireplaces
MI-FlexFlexible Liner
Chimney FlueChimney Flue
Connecting PipesConnecting Pipes
Fans Flashings CowlsFans Flashings Cowls
Installation PartsInstallation Parts
After Care PartsAfter Care Parts

The best selling flue liner in the UK. Suitable for gas, oil, and approved solid fuels. Call our advisers on 01670 206 999 if you need any help choosing.

£14.99

20-300-C

Top Clamp - Ø 300

Top Clamp - Ø 300

£14.99

20-300-P

Top Plate - Ø 300

Top Plate - Ø 300

£49.49

34-300-A

Triplelock - Adaptor to Single Wall - Ø 300

Triplelock - Adaptor to Single Wall - Ø 300

OUT OF STOCK

£102.99

20-300-NC

Nose Cone - Ø 300

Nose Cone - Ø 300

Your 300MM (12 INCH) Questions Answered

What is the difference between MI-Flex and Gas FLEX? -

MI-Flex and Gas FLEX are two premium flue liner brands offered by National Flues. MI-Flex is known for its flexibility and ease of installation, while Gas FLEX is specifically designed for gas applications, ensuring optimal performance and safety.

Are top and bottom fixings necessary for a 300mm flue liner? +

Do I need a register plate with a 300mm flue liner? +

Can the 300mm (12 inch) flue liner be used for both gas and oil appliances? +

How long does a 300mm flue liner last? +

Are National Flues' products compliant with industry standards? +

Can I install a 300mm flue liner myself? +

Do National Flues provide warranty for their 300mm flue liners? +

When it comes to ensuring the safety and efficiency of your gas or oil fireplace, the 300mm (12 inch) flue liner is a crucial component. At National Flues, we offer the finest quality flue systems designed specifically for gas and oil applications. Our 316L grade flue liner provides superior corrosion resistance, durability, and performance, making it the ideal choice for modern heating systems. With easy installation and compatibility with various fittings, our 300mm flue liner guarantees a seamless and reliable flue setup.
Why Buy 300MM (12 INCH) Products
The 300mm (12 inch) flue liner is essential for venting gases from gas and oil appliances safely out of your home. It ensures proper airflow, enhances the efficiency of your heating system, and reduces the risk of dangerous fumes entering your living space. Our versatile flue liner can be used in a wide range of applications, including domestic fireplaces, stoves, and boilers. Whether you're a homeowner or a professional installer, National Flues' 300mm flue liner is a trusted choice for a safe and effective flue system.

Trusted By Trade Professionals

Our 300MM (12 INCH) products and services are trusted by hundreds of professionals nationwide. We're committed to providing quality and reliability that meets the high standards of our customers.

Dedicated Support

Experience our unparalleled customer service and support when you buy 300MM (12 INCH) from National Flues. Our team is here to assist you every step of the way, ensuring your needs are met with expertise and care.

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