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Increasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150 (20-125-MR1)

National Flues proudly presents the Increasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150. This premium adaptor is engineered for a seamless connection between rigid single-wall flues and MI-FLEX flexible liners, crafted from robust 316L stainless steel. Ideal for wood, oil, gas, and smokeless coal, it meets stringent UK standards including HETAS and CE. Enhance your flue system today with National Flues' trusted MI-FLEX accessories.
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£42.49
Give us a call if you find it cheaper and we'll try to price match.

 

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At a Glance

  • Rigid to flexible flue transition
  • Crafted from durable 316L stainless steel
  • Withstands temperatures up to 600°C
  • Complies with UK Building Regulations (Document J)
  • Suitable for wood, smokeless coal, gas, and oil

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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:

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

Our Increasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150 is a premium-quality installation fitting specifically designed for seamless integration with MI-FLEX 316 and 904 flexible flue liners. This adaptor ensures a smooth transition from a rigid single-wall flue to a flexible flue liner, increasing diameter by 25mm in the process. Crafted from durable 1mm stainless steel, it's built to withstand temperatures up to 600°C, making it suitable for use with wood (less than 20% moisture), smokeless coal, gas, and oil.

Adhering to Building Regulations Document J, this flexible flue liner must be fully enclosed within a masonry chimney, as non-masonry enclosures like timber or plasterboard are not acceptable. The bottom fixings ensure a tight, gas-proof seal, with fire cement, ceramic rope, tape, or high-temperature sealant recommended for optimal security. Our design not only meets rigorous safety standards but also facilitates easy maintenance and sweeping, ensuring your chimney system remains in top working order.

Regular sweeping, especially for solid fuel applications, is recommended twice yearly by a competent person or a HETAS registered sweep to prevent the build-up of deposits and blockages.

SKU: 20-125-MR1

Technical Specifications
SKU20-125-MR1
ModelIncreasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150
Material316L Stainless Steel
Wall Thickness1mm
Temperature ToleranceUp to 600°C
ComplianceHETAS, CE, Building Regs Document J
Fuel CompatibilityWood (<20% moisture), Smokeless Coal, Gas, Oil
System CompatibilityMI-FLEX 316 & 904 flexible flue liners
• Ensure the adaptor is securely fixed between the rigid single-wall flue and the MI-FLEX liner. • Use recommended sealing materials (fire cement, ceramic rope, high-temperature tape, or sealant) to achieve a gas-tight seal. • Install the flexible liner fully within a masonry chimney in accordance with Building Regulations Document J. • Regularly inspect and sweep the system to prevent build-up of deposits and maintain performance. • Professional installation is advised to ensure compliance and optimal safety.

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

Absolutely, it complies with Building Regulations Document J, requiring flexible flue liners to be fully enclosed within a masonry chimney.

The adaptor is designed to withstand temperatures of up to 600°C.

Ensure a gas-tight seal by securing the bottom fixing into the connecting flue below and the flexible flue liner above. Fire cement, ceramic rope, tape, or high-temperature sealant is recommended.

While basic inspections can be done by the homeowner, sweeping and more thorough maintenance should be performed by a competent person, ideally a HETAS registered sweep.

For chimneys serving solid fuel appliances, sweeping is recommended at least twice a year, at the end of the heating season and before the start of the next.

Avoid chemical cleaners and mild steel tools. Instead, use tools specifically designed for sweeping stainless steel chimneys.
Delivery Information +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Wednesday, April 30th. If you need faster stove or fireplace delivery please give us a call. We can often 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. Mi-Flex offers a lifetime guarantee. Returns for damaged items are covered by insurance; non-damaged returns incur return delivery costs.

Price Match Guarantee +

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.

Read our review in our Increasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150 buyers guide

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Secure your Increasing MI-FLEX Adaptor today for a safe, efficient, and regulation-compliant flue system.

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