Screw-FIX Increaser - Ø 125-150mm (25-125-MR)
What it’s for
Full features & benefits
- 316L Stainless Steel: Offers excellent durability and high temperature resistance (up to 600°C) ensuring long-lasting performance.
- Seamless Diameter Transition: Guarantees a robust connection between a rigid single wall flue system and a MI-FLEX liner, enhancing system efficiency.
- Regulatory Compliance: Installation within a masonry chimney ensures adherence to Building Regulations Document J for a safe and secure setup.
- Versatile Fuel Compatibility: Ideal for various fuels such as wood (with moisture below 20%), gas, oil, and smokeless coal, providing flexible usage.
- Optimised for Maintenance: Engineered to support regular cleaning and inspection, minimising downtime and maintenance costs.
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Fast deliveryMonday, November 17th*
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Best PriceCall us to beat any price you found online.
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At a Glance
- 316L Stainless Steel Construction
- Increases flue diameter from 125mm to 150mm
- Fully compliant with Building Regulations Document J
- Suitable for multiple fuel types: wood, gas, oil, smokeless coal
- Designed for seamless connection with MI-FLEX flexible flue liners
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
- Details
- Specs
- Install/Packs
- FAQs
The Screw-FIX Increaser Ø 125-150mm is a high-quality 0.6mm 316 stainless steel adaptor designed for connecting a rigid single wall flue system to a MI-FLEX flexible flue liner. Specifically meant to facilitate a seamless transition, it increases the diameter from 125mm to 150mm. The increaser is especially designed for use with MI-FLEX 316 and 904 multi-fuel flexible flue liners, making it integral to a complete chimney system.Adhering to Building Regulations Document J, this fitting can only be installed within a masonry chimney, ensuring safety and compliance.
It is suitable for various fuel types, including wood (with moisture content below 20%), smokeless coal, gas, and oil, and can withstand temperatures up to 600°C (T600 designation). The installation mandates that the bottom fixing be secured properly to ensure a gas-tight seal, with the use of fire cement, ceramic rope or tape, or high-temperature sealant recommended.For efficient maintenance and longevity of your chimney system, ensure regular sweeping by a competent person, ideally a HETAS registered sweep for solid fuel applications. It's crucial to check the chimney system twice a year, before and after the heating season, to avoid blockages and buildup of deposits like bird nests.
SKU: 25-125-MR
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.
This is us — real advice over the phone, or at the counter, and real stock in our warehouse.
| Technical Specifications | |
|---|---|
| Material | 316L Stainless Steel |
| Diameter Increase | 125mm to 150mm |
| Temperature Tolerance | Up to 600°C |
| Design Standard | BSEN 1856-2 T600 N1 W V2 L50012 G |
| Suitable For | Wood (moisture <20%), Gas, Oil, Smokeless Coal |
| System Compatibility | MI-FLEX Accessories MF20 |
| Installation | Within masonry chimneys in line with Building Regulations Document J |