Twin Wall to Flex Adaptor Ø 125
At a Glance
- - Seamless transition from twin wall systems to flexible liners
- - Constructed from high-grade 304 and 316 stainless steel
- - Compressed rockwool insulation (200kg/m³) for optimal heat retention
- - Fully welded design ensuring durability
- - Maintains a safe 50mm clearance from combustibles
- - HETAS approved and CE marked for safety and compliance
- - Designed for both solid fuel and gas/oil appliances

Please Note: All dimensions refer to the internal diameter of flues. If unsure, please call 01670 206999 to ensure you choose the correct products.
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: [email protected]
- Info
- Specs
- Install
- FAQs
The Twin Wall to Flex Adaptor Ø 125 is essential for connecting your chimney and flue system, ensuring a secure transition from TWPro twin wall systems to MI-Flues multi-fuel liners. Specifically designed for use with solid fuel and gas/oil appliances, including wood stoves, gas coal effect fires, and boilers, this adaptor guarantees high efficiency and safety. Constructed with 0.4mm thick outer and inner skins made of 304 and 316 grade stainless steel respectively, it boasts insulation of compressed rockwool with a density of 200kg/m³.
Fully welded for additional durability, every part maintains a safe 50mm distance to combustible materials. TWPro components are HETAS Approved and CE marked, with designations EN1856-1 T600 N1 W V2 L50040 G50 and EN1856-1 T200 W V2 L50040 O20. Installation is straightforward, requiring a locking band to secure the parts.
Ensure all transitions occur inside an existing class 1 chimney, with no flexible liner visible externally, for optimal performance.
SKU: 2-125-099
Technical Specifications | |
---|---|
Model | Twin Wall to Flex Adaptor Ø 125 |
SKU | 2-125-099 |
Inner Material | 316L Stainless Steel, 0.4mm thick |
Outer Material | 304 Stainless Steel, 0.4mm thick |
Insulation | Compressed Rockwool (200kg/m³) |
Appliance Compatibility | Wood stoves, gas coal effect fires, oil/gas boilers, and other solid fuel appliances |
Approvals | HETAS Approved / CE Marked |
Designations | EN1856-1 T600 N1 W V2 L50040 G50, EN1856-1 T200 W V2 L50040 O20 |
Minimum Clearance To Combustibles | 50mm |
Installation Requirement | Locking band for secure coupling, inside an existing class 1 chimney |
Delivery Information +
We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Friday, April 4th. 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. If you find it cheaper within 48 hours, we'll refund the difference.
Compatible and other products that may be of interest...
National Flues Ltd Verdict
National Flues highly recommends the Twin Wall to Flex Adaptor Ø 125 for its reliable performance and robust construction. Serving both retail and trade customers, we ensure swift nationwide delivery and unbeatable prices.
The Twin Wall to Flex Adaptor Ø 125 is used to create a seamless transition from TWPro twin wall systems to MI-Flues multi-fuel liners, ensuring safe and efficient ventilation for solid fuel and gas/oil appliances.
National Flues is a trusted supplier of quality fireplaces and flues across the UK, offering competitive prices, dependable delivery, and robust options for both retail and trade customers. Our commitment to quality and customer service has made us a leader in the industry.
