Free Delivery over £100+ 5on Trustpilot Browse our popular stoves Fast Mainland UK Delivery Buy stoves with install packs Call 01670 206 999 for help

Top Clamp - Ø 300 (20-300-C)

National Flues presents the Top Clamp - Ø 300, a premium chimney accessory designed for flawless integration with MI-FLEX flexible flue liners. Engineered for durability with high-quality 316L stainless steel, this product delivers exceptional performance in wood, smokeless coal, gas, or oil heating systems. Read more...
Now only £15.99
Give us a call if you find it cheaper and we'll normally price match.
  • Fast deliveryFriday, November 14th*
  • Best PriceCall us to beat any price you found online.
  • Secure checkoutCard· Google/Apple Pay· Klarna· Paypal

 

Payment Options

At a Glance

  • High-quality 316L stainless steel construction
  • Compatible with MI-FLEX 316 and 904 flexible flue liners
  • Withstands temperatures up to 600°C (T600 designation)
  • Complies with Building Regulations Document J
  • Provides robust support to stabilise chimney linings

We Won't Be Beaten On Price

At National Flues, we continuously monitor competitor prices. This ensures that we consistently offer you the best deals on all our products. Here’s how we keep your costs low:

  • Daily Price Matching: Our team adjusts prices to ensure we stay competitive.
  • Bulk Purchasing Power: We sell a lot, so we can negotiate better rates with suppliers, passing the savings directly to you.
  • Operational Efficiency: We have streamlined processes to reduce overhead.

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: sales@nationalflues.com

The Top Clamp - Ø 300 is a crucial component for ensuring the stability and effectiveness of your chimney system. Perfectly designed for use with MI-FLEX 316 and 904 flexible flue liners, this top clamp provides essential support by bearing the vertical weight of the flue liner at the top of the stack. All MI-FLEX accessories, including this top clamp, comply with Building Regulations Document J, which mandates that a flexible flue liner must be installed completely enclosed inside a masonry chimney.

The top clamp is suitable for appliances operating at temperatures up to 600°C (T600 designation), making it ideal for use with wood (under 20% moisture), smokeless coal, gas, and oil. For optimal functionality, ensure that the chimney stack is fully weatherproofed and of sound construction, and that all chimney pots are in good condition with appropriate flaunching. Regular maintenance and sweeping are essential for safe operation, particularly with solid fuel appliances.

Adhering to recommended cleaning schedules will help prevent blockages and ensure long-term efficiency.

SKU: 20-300-C

Delivery Information* +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Friday, November 14th. This is based on current lead times. Bear in mind that it is a busy time of year. If you need a product delivered by a specific time in the next 7 days, then please give us a call on 01670 206 999. Visit our Shipping Information page for more information.

About National Flues Ltd +

We began over 30 years ago as a fireplace shop in the North East. We now supply hundreds of trade professionals and thousands of retail customers, all across the UK, every month. We are still a family owned business, lead by the MD Neil, and always try our best to deliver the best possible experience. We also price match, so give us a call if you find this cheaper and want to buy from us. Visit our about us page to read a bit more.

Technical Specifications
SKU20-300-C
Product NameTop Clamp - Ø 300
Material316L Stainless Steel
CompatibilityMI-FLEX 316 and 904 flexible flue liners
Temperature RatingUp to 600°C (T600)
Fuel TypesWood (under 20% moisture), Smokeless coal, Gas, Oil
ComplianceHETAS / CE, Building Regulations Document J
FinishNatural / Stainless Steel
SystemMI-FLEX Accessories MF20
• Ensure the chimney stack is fully weatherproofed and built to proper standards before installation. • Confirm the integrity of chimney pots and use correct flaunching to maintain secure connections. • Follow all manufacturer instructions and Building Regulations Document J for optimal safety. • Regular maintenance, including at least biannual sweeping for solid fuel appliances, is essential to prevent blockages. • Always consult a competent and certified professional when undertaking installation or maintenance tasks.

The Top Clamp - Ø 300 is designed for use with MI-FLEX 316 and 904 flexible flue liners.

The installation must adhere to Building Regulations Document J, which requires the flexible flue liner to be completely enclosed inside a masonry chimney.

The Top Clamp - Ø 300 is suitable for use on appliances operating up to 600°C, designated as T600.

The top clamp is suitable for use with wood (under 20% moisture), smokeless coal, gas, and oil.

For solid fuel appliances, the chimney should be swept at least twice a year – once at the start and once at the end of the heating season. Chimneys serving other types of appliances should be swept at least once a year.

Chimney sweeping should be carried out by a competent person. For solid fuel appliances, a HETAS registered sweep is recommended.

Ensure that chimney pots are in good condition without cracks, and the chimney stack is fully weatherproofed and of sound construction before installation.

 

Call the Experts   8am-5pm
👀 5 people watching this