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Screw-FIX Increaser - Ø 100-125mm (25-100-MR)
National Flues proudly presents the Screw-FIX Increaser Ø 100-125mm, a premium flue system accessory designed for seamless transitions. This high-quality adaptor connects rigid single wall systems to MI-FLEX flexible liners efficiently, ensuring both safety and performance. Engineered from robust 316L stainless steel, this essential component is ideal for wood, oil, gas and smokeless coal appliances. Enhance your chimney's integrity and functionality with our superior product, perfect for those seeking reliable, compliant, and durable flue solutions.
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In Stock
£23.49
Give us a call if you find it cheaper and we'll try to price match.
At a Glance
Manufactured from premium 0.6mm 316L stainless steel
Withstands temperatures up to 600°C (T600 designation)
Ensures a secure, gas‐tight connection between rigid single wall and MI-FLEX flexible flue liners
Complies with BSEN 1856-2 and Building Regulations Document J
Suitable for use with wood (<20% moisture), oil, gas, and smokeless coal
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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.
The Screw-FIX Increaser Ø 100-125mm is a premium accessory designed to ensure a seamless and secure connection between a rigid single wall connecting flue system and MI-FLEX flexible flue liners. Made from 0.6mm 316 stainless steel, this increaser offers superior durability and resistance to high temperatures, supporting appliances up to 600°C (T600 designation). In compliance with Building Regulations Document J, this increaser is suitable for use with wood with less than 20% moisture, smokeless coal, gas, and oil appliances.
To achieve a complete and secure chimney system, it is crucial to use the increaser within the masonry chimney, ensuring no flexible flue liner is exposed. Proper installation includes securing the connection with fire cement, ceramic rope, or high-temperature sealant, ensuring a gas-tight seal. For maintenance, sweeping should be conducted by a competent person, ideally a HETAS registered sweep, to keep your system in optimal condition.
SKU: 25-100-MR
Technical Specifications
SKU
25-100-MR
Size
u00d8 100-125mm
Material
0.6mm 316L Stainless Steel
Temperature Rating
Up to 600u00b0C
Standard
BSEN 1856-2 T600 N1 W V2 L50012 G
Suitable Fuels
Wood (<20% moisture), Oil, Gas, Smokeless Coal
Installation
Within enclosed masonry chimney; secure with fire cement, ceramic rope or high-temperature sealant
Approvals
CE / HETAS Compliant
• Always ensure the flue system is fully enclosed within a masonry chimney – the use of the Screw-FIX Increaser outside this context is not permitted.
• Prior to installation, inspect the ceiling and chimney lining to ensure that no flexible liner is exposed beyond the confining masonry.
• Use approved fire cement, ceramic rope, or a high-temperature sealant when fixing the increaser to guarantee a gas-tight seal.
• Ensure that all components are clean and free from obstructions before assembly.
• If in doubt, consult a HETAS registered professional to perform the installation, ensuring compliance with Building Regulations Document J and safety standards.
The Screw-FIX Increaser Ø 100-125mm is used to connect a rigid single wall flue system to an MI-FLEX flexible flue liner, enabling a smooth diameter transition within a chimney system.
Yes, the Screw-FIX Increaser is designed to withstand temperatures up to 600°C (T600 designation), making it suitable for various heating appliances.
To ensure a secure and gas-tight seal, use fire cement, ceramic rope, or high-temperature sealant when installing the Screw-FIX Increaser.
According to Building Regulations Document J, the Screw-FIX Increaser should only be used within a completely enclosed masonry chimney. Non-masonry enclosures like timber or plasterboard are not acceptable.
For solid fuel applications, it's recommended to sweep your chimney at least twice a year, ideally at the end and start of the heating season. For other fuels, an annual maintenance check is sufficient.
For solid fuel applications, you can find a list of HETAS registered sweeps on the HETAS website (www.hetas.co.uk) to ensure competent maintenance of your chimney system.
Avoid using chemical cleaners or mild steel tools when sweeping the chimney, as these can damage the stainless steel components. Always use appropriate materials for cleaning.
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.
The proper functioning of your chimney system is crucial for both safety and efficiency in your home. When upgrading or maintaining your flue system, choosing the right accessories is paramount. The Screw-FIX Increaser Ø 100-125mm, offered by National Flues, provides a reliable solution for creating a secure junction between a rigid single wall flue system and an MI-FLEX flexible flue liner. In this comprehensive guide, we explore every aspect of this product, ensuring you know exactly what to expect and why it is the best choice for your home.
Product Overview
The Screw-FIX Increaser is an expertly engineered accessory designed to ensure a seamless diameter transition in your chimney. Manufactured from 0.6mm 316L stainless steel, it boasts remarkable durability and resistance to high temperatures, supporting appliances that reach up to 600°C. This product complies with stringent standards such as BSEN 1856-2 and Building Regulations Document J, making it a reliable component for modern flue systems. It is suitable for heating appliances that use wood (with a moisture content of less than 20%), oil, gas, and smokeless coal.
Key Features and Benefits
Durable Construction: The use of premium 316L stainless steel means that the Screw-FIX Increaser not only delivers long-lasting performance but also resists corrosion and degradation over time. This is particularly beneficial for systems exposed to fluctuating temperatures and environmental conditions.
High Temperature Tolerance: With a temperature rating of up to 600°C, this accessory is designed to operate safely under high heat conditions. This capability ensures that your chimney system remains safe even during prolonged periods of heavy use.
Seamless Fitting: The innovative design of the increaser provides a smooth transition between a rigid flue and a flexible liner, thereby eliminating potential issues related to improper fitting and gas leaks. This reduces the risk of heat loss and improves overall system efficiency.
Regulatory Compliance: By meeting the requirements specified in BSEN 1856-2 and Building Regulations Document J, the Screw-FIX Increaser offers peace of mind to homeowners and professionals alike. Compliance with these standards ensures that your installation adheres to strict safety and performance guidelines.
Installation Guidelines
When installing the Screw-FIX Increaser, it is vital to follow the manufacturer’s instructions to guarantee maximum performance and safety. The accessory should be installed within an entirely enclosed masonry chimney to prevent any exposure of the flexible flue liner. Use a suitable fixing medium such as fire cement, ceramic rope, or a high-temperature sealant to secure the connection firmly. These measures are crucial in creating a gas-tight seal and maintaining the overall integrity of your chimney system. If you are unsure about any steps, it is highly recommended to consult with a HETAS registered professional who can ensure that the installation is carried out in accordance with all relevant regulations.
Addressing Common Objections
One frequent concern among homeowners is whether the accessory can withstand long-term use in extreme temperatures. Rest assured, the Screw-FIX Increaser has been rigorously tested to endure temperatures up to 600°C, making it highly reliable for high-heat applications. Another common question is about compatibility with different fuels. This product is versatile and is safe to use with wood (provided the moisture content is below 20%), oil, gas, and smokeless coal, giving you flexibility regardless of your heating preference. Some customers may worry about the installation process. Thanks to clear, step-by-step guidance and the option to consult certified professionals, the installation is straightforward and stress-free.
Practical Applications and Usage
In a modern home or commercial installation, the reliability of your chimney system is paramount. The Screw-FIX Increaser plays an essential role by ensuring that flexible flue liners are securely and effectively connected to rigid systems, eliminating potential hazards such as gas leaks or heat loss. Its unique design not only simplifies the fitting process but also significantly enhances the durability of your flue installation. The accessory is particularly beneficial in retrofit projects where older chimney systems require modernisation to meet current safety regulations.
Why National Flues?
At National Flues, we pride ourselves on offering high-quality, compliant, and reliable chimney system components. Our products are designed to meet the rigorous demands of both residential and commercial applications. With nationwide delivery and exceptional customer support, you can be assured that you are choosing a product backed by a brand renowned for its expertise and commitment to safety. The Screw-FIX Increaser Ø 100-125mm is a testament to our dedication to quality, providing a critical link that ensures your flue system operates at its peak efficiency while adhering to all necessary standards.
Final Thoughts
The Screw-FIX Increaser Ø 100-125mm is not just an accessory; it is an investment in the longevity and safety of your heating system. With its robust construction, high-temperature performance, and stringent compliance with industry standards, it offers exceptional value. Whether you are installing a new chimney system or upgrading an existing one, this product is a vital component that ensures a seamless connection and long-term reliability.
Choosing the right accessories is essential for the optimal performance of your chimney system. The Screw-FIX Increaser stands out as a trusted solution that combines durability, safety, and ease of installation. Detailed installation guidelines and strong industry credentials make it an ideal choice for both DIY enthusiasts and professional installers.
Buy now or call 01670 206 999.
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