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MI-FLEX Adaptor - Ø 250 (20-250-MAE)

The MI-FLEX Adaptor - Ø 250mm from National Flues is a premium stainless steel chimney connector engineered for secure integration between rigid flue systems and MI-FLEX flexible liners. Designed for multi-fuel applications including wood, smokeless coal, gas, and oil, this robust adaptor meets stringent UK Building Regulations and ensures a dependable, gas-tight installation. Read more...
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At a Glance

  • Crafted from durable 0.6mm 316L stainless steel
  • Securely connects single wall flue systems to MI-FLEX flexible liners
  • High temperature tolerance up to 600°C for efficient multi-fuel use
  • Suitable for wood (under 20% moisture), smokeless coal, gas, and oil
  • Compliant with UK Building Regulations when installed in masonry chimneys
  • Achieves a reliable gas‐tight seal with the proper sealants
  • Low stock alert – act swiftly to secure this essential adaptor

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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.
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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).

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Have Questions?
Phone: 01670 206999
Email: sales@nationalflues.com

The MI-FLEX Adaptor - Ø 250mm, made from high-quality 0.6mm 316 stainless steel, ensures a seamless connection between your single wall flue system and MI-FLEX flexible flue liners. This robust adaptor, part of our MF20 MI-FLEX accessories range, is ideal for multi-fuel applications, handling temperatures up to 600°C. Whether you’re using wood with less than 20% moisture content, smokeless coal, gas, or oil, this adaptor is designed for reliable performance within a masonry chimney.

Ensure a gas-tight seal using fire cement, ceramic rope, tape, or high-temperature sealant. Compliance with Building Regulations Document J is essential, and remember, no flexible flue should ever be visible outside the masonry chimney. Maintenance is straightforward: inspect and clean the system annually, with biannual sweeps recommended for solid fuel setups.

SKU: 20-250-MAE

Delivery Information* +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Monday, November 17th. 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
Material316L Stainless Steel (0.6mm thick)
Nominal DiameterØ 250mm
Operating TemperatureUp to 600°C
ComplianceHETAS / CE; Building Regulations Document J
FuelsWood (under 20% moisture), Smokeless Coal, Gas, Oil
Seal RecommendationFire cement, Ceramic rope, High-temperature sealant, Tape
InstallationFor use exclusively within masonry chimney enclosures
Product Code20-250-MAE
Ensure the adaptor is installed as part of a complete masonry chimney system. Prior to installation, verify that all components including the rigid single wall flue and MI-FLEX flexible liner conform to the required specifications. A gas-tight connection is vital; follow the manufacturer's guidelines and use approved sealing materials such as fire cement, ceramic rope, tape, or high-temperature sealant to secure the joint. Always remember: no flexible flue liner should be visible outside the masonry chimney. Additionally, ensure alignment and secure fixation of components to prevent undue stress during operation. Regular inspection and maintenance are recommended; inspect your chimney system annually and consider biannual sweeps for installations using solid fuels. Adhering to Building Regulations Document J is mandatory for ensuring both safety and compliance.

The MI-FLEX Adaptor is crafted from high-quality 0.6mm 316 stainless steel, providing excellent durability and resistance to high temperatures.

Yes, the MI-FLEX Adaptor is suitable for use with wood (less than 20% moisture), smokeless coal, gas, and oil.

The adaptor is designed to withstand temperatures up to 600°C (T600 designation).

Yes, when installed in a masonry chimney as per Building Regulations Document J, the adaptor ensures compliance.

To achieve a gas-tight seal, use fire cement, ceramic rope, tape, or high-temperature sealant.

The chimney system should be inspected and cleaned at least once a year, with biannual sweeps recommended for solid fuel applications.

No, the adaptor and flexible flue liners must be installed within a masonry chimney. Non-masonry enclosures are not acceptable.

 

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