Top Hat Adaptor - Ø 125
At a Glance
- Constructed from robust 316L stainless steel (0.6mm thick)
- Withstands high temperatures up to 600°C (T600 designation)
- Complies with BSEN standards and Building Regulations Document J
- Seamlessly integrates with MI-FLEX 316 and 904 flexible flue liners
- Suitable for wood (less than 20% moisture), oil, gas, and smokeless coal

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
- Info
- Specs
- Install
- FAQs
The Top Hat Adaptor - Ø 125 from National Flues is a high-quality essential for any chimney system. Constructed from robust 0.6mm 316 stainless steel, this adaptor is designed for optimal performance and longevity. It seamlessly integrates with MI-FLEX 316 and 904 flexible flue liners to form a complete chimney system.
This sturdy fitting is built to withstand up to 600°C (T600 designation), making it perfect for multiple fuel applications including wood with less than 20% moisture, smokeless coal, gas, and oil. Designed to comply with Building Regulations Document J, this adaptor must be installed completely enclosed inside a masonry chimney. For safety and efficiency, ensure the bottom fixing is gas-tight using fire cement, ceramic rope, or high-temperature sealant.
The Top Hat Adaptor fits at the base of the chimney, securely connecting the flue system to the flexible liner, and features a convenient square cover plate for aesthetic integrity. Maintenance is straightforward as the system allows easy access for sweeping and inspection. Be sure to have your chimney cleaned at least once or twice a year by a competent person.
Choose the Top Hat Adaptor for a reliable, durable solution to your chimney needs.
SKU: 20-125-THA
Delivery Information +
We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Monday, April 7th. 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.
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National Flues Ltd Verdict
The Top Hat Adaptor - Ø 125 is an essential component for any chimney installation. Made from premium 316 stainless steel, this adaptor offers durability and seamless integration. Our nationwide delivery ensures you can rely on National Flues for both retail and trade needs.
The Top Hat Adaptor is designed to facilitate a seamless and secure connection between a chimney flue system and MI-FLEX flexible flue liners, ensuring efficient and safe operation of stoves and other heating appliances.
National Flues is a leading supplier of high-quality fireplaces and flues, serving retail and trade customers across the UK. Renowned for competitive pricing and reliable delivery, National Flues offers secure online payments, making it the go-to choice for all your chimney needs.
