× National Flues
We Will NOT Be Beaten on Price.
Free Delivery on Orders Over £100
5 Star Reviewed on Trustpilot
Free Flue Design Service Available
Help? 01670 206999 (8am-5pm)

 

Quality 300mm (12 inch) Flue Liner & Accessories - Buy Online

Discover the superior 300mm (12 inch) flue liner and accessories designed to enhance your fireplace experience. Our MI-Flex and 316L Mi-FLEX products are the go-to choice for efficient and safe flue systems. From easy installations with bottom fixings to top-quality terminals and insulation, we offer everything you need under one roof. Elevate your fireplace with our premier 300mm range for a seamless and durable solution.

Shop By Department

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.

£93.49

35Z-300-1

316L Mi-FLEX 300mm x 1m CUT LENGTH

316L Mi-FLEX 300mm x 1m CUT LENGTH

£145.99

20-300-GHL

Gather Hood (400x300) - Ø 300

Gather Hood (400x300) - Ø 300

£35.49

20-300-MAE

MI-FLEX Adaptor - Ø 300

MI-FLEX Adaptor - Ø 300

£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

£95.99

20-300-J

Joiner - Ø 300

Joiner - Ø 300

OUT OF STOCK

£102.99

20-300-NC

Nose Cone - Ø 300

Nose Cone - Ø 300

£1.99

20-CNP

Chimney Notice Plate

Chimney Notice Plate

£87.49

20-CNP48

Chimney Notice Plate - 50 Pack

Chimney Notice Plate - 50 Pack

£26.99

90-LECA

Leca 50L Bag

Leca 50L Bag

£33.99

90-VERM

Vermiculite (100L Bag)

Vermiculite (100L Bag)

Your 300MM (12 INCH) Questions Answered

What makes the 300mm flue liner stand out from others? -

Our 300mm flue liner is crafted from premium materials like 316L Mi-FLEX, offering exceptional durability and corrosion resistance.

Are the bottom fixings included with the 300mm flue liner? +

How can I ensure a proper fit for the 300mm flue liner? +

Do I need insulation with the 300mm flue liner? +

Can I use the 300mm flue liner for a wood-burning fireplace? +

Do you offer warranties on the 300mm flue liner products? +

Is professional installation recommended for the 300mm flue liner? +

When it comes to ensuring your fireplace operates at its best, investing in a high-quality 300mm (12 inch) flue liner is essential. Our range of products, such as the 316L Mi-FLEX 300mm x 1m cut length, guarantees top-notch performance and longevity. Made with precision and durability in mind, our flue liners provide optimal airflow and protection for your home. Whether you're a professional installer or a DIY enthusiast, our 300mm range caters to all needs, ensuring a smooth and efficient installation process.
Why Buy 300MM (12 INCH) Products
The 300mm (12 inch) flue liner and accessories are perfect for both residential and commercial fireplace setups. These products are ideal for renovating existing fireplace systems, ensuring they meet safety standards and operate efficiently. The insulation options available help in maintaining the right temperature within the flue, optimizing the overall performance of your fireplace. From register plates to bottom fixings, each accessory is crafted to enhance the functionality and safety of your 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.

Multiple Payment Options- including Klarna, Clearpay, Mastercard, Visa and Paypal
Free Design Service