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The National Flues Pack 504 is a premier 125mm flue installation kit that offers a reliable, compliant, and efficient solution for chimney flue liner installations. Ideal for both professional installers and DIY enthusiasts, this top-of-the-range kit provides all necessary installation accessories, ensuring a smooth and trouble-free setup while maintaining full regulatory compliance. If you are searching for a superior chimney installation kit that delivers durability and performance, the Pack 504 by National Flues is your ultimate choice.
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In Stock
£47.49
Give us a call if you find it cheaper and we'll try to price match.
At a Glance
All-inclusive installation kit for 125mm MI-FLEX flue liners
Meets Building Regulations Document J requirements
Constructed from robust 316L stainless steel
Compatible with multiple fuel types (wood, smokeless coal, gas, oil)
Includes top plate, top clamp, nose cone, increasing adaptor and chimney notice plate
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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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Free Delivery Over £100: Orders over £100 are free delivery (call us if delivery is required outside the mainland UK).
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The Pack 504 - (125mm, P/C/PS/N/CNP/20-100-MR) is an all-inclusive installation kit designed for MI-FLEX 316 and 904 flexible flue liners. Perfectly suited for creating a comprehensive chimney system, this kit allows you to replace an existing chimney pot and install a new flue liner with ease. This pack includes a 125mm Top Plate, Top Clamp, Nose Cone, and an Increasing Adaptor to Black Pipe or Single Wall Flue with dimensions from 100mm SW to 125mm Flex.
Additionally, a Chimney Notice Plate is provided. Building Regulations Document J stipulates that flexible flue liners must be fully enclosed within a masonry chimney, and this kit meets all necessary requirements. Suitable for appliances up to 600°C and compatible with wood (under 20% moisture), smokeless coal, gas, and oil, it ensures a robust and durable installation.
SKU: 20-125-P504
Technical Specifications
SKU
20-125-P504
Product Name
Pack 504 - (125mm, P/C/PS/N/CNP/20-100-MR)
Material
316L Stainless Steel
Dimensions
125mm Top Plate; Increasing adaptor fits 100mm SW to 125mm Flex
Finish
Natural / Stainless Steel
Approvals
HETAS, CE
Compatible Fuels
Wood (<20% moisture), Smokeless Coal, Gas, Oil
System
MI-FLEX Accessories MF20
Before installation, ensure that the entire chimney flue liner is fully enclosed within a masonry structure as mandated by Building Regulations Document J. The Pack 504 is designed to replace an existing chimney pot and includes all components required for a complete installation. Begin by carefully removing the old chimney pot and cleaning the working area. Install the 125mm top plate and secure it firmly using the provided top clamp. Next, position the nose cone to ensure a neat finish and effective protection against weather exposure. Attach the increasing adaptor to transition from a 100mm Single Wall Flue (SW) to a 125mm MI-FLEX flue liner, ensuring a snug and secure fit. Finally, fix the chimney notice plate in a visible location to display essential safety and maintenance information. Note: This kit is not recommended for use in timber or plasterboard enclosures. Always consult a qualified professional if unsure about any aspect of the installation. Regular maintenance and annual inspections are strongly advised to keep your chimney system functioning safely.
The kit includes a 125mm Top Plate, Top Clamp, Nose Cone, Increasing Adaptor to Black Pipe or Single Wall Flue (100mm SW to 125mm Flex), and a Chimney Notice Plate.
Yes, this kit is suitable for wood (under 20% moisture), smokeless coal, gas, and oil appliances up to 600°C.
No, Building Regulations Document J requires that a flexible flue liner must be installed completely enclosed inside a masonry chimney.
While the MI-FLEX liner itself is not included, this kit provides all necessary accessories for installation. You may also need a cowl or terminal for weather and bird protection.
Cleaning and inspection should be carried out at least once a year. For solid fuel appliances, it is recommended to sweep the chimney at least twice a year.
Avoid using chemical cleaners or mild steel tools on stainless steel chimneys. It is best to use a professional sweep listed on HETAS.
The Chimney Notice Plate provides important information about the chimney system, including its design and maintenance requirements, ensuring safety and compliance.
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.
Comprehensive Buyers Guide for the Pack 504 Installation Kit
The Pack 504 Installation Kit from National Flues is designed for homeowners, DIY enthusiasts, and professionals looking for a complete solution to upgrade or replace their chimney systems. This guide aims to provide you with an in-depth look at the product, its features, installation process, and how it meets the demanding safety and performance standards set by Building Regulations Document J.
Product Overview
The Pack 504 is a fully integrated installation kit designed specifically for 125mm MI-FLEX flue liners. Manufactured from high-quality 316L stainless steel, this kit offers not only durability but also a sleek, natural finish that complements any chimney design. The comprehensive package includes a 125mm top plate, a top clamp, a nose cone, an increasing adaptor to transition from a 100mm single wall flue to a 125mm flexible flue liner, and a chimney notice plate. This thoughtful assortment of components ensures that your chimney installation is both safe and aesthetically pleasing.
Key Features and Benefits
All-Inclusive Design: The kit encompasses every element needed for a complete chimney upgrade. This eliminates the need to search for individual components, saving both time and money.
Regulatory Compliance: Designed in accordance with Building Regulations Document J, the Pack 504 ensures that every installation meets the necessary safety standards, providing peace of mind and legal protection.
Durability and Strength: Crafted from 316L stainless steel, the components offer excellent resistance to corrosion and high temperatures. This translates into long-term reliability and minimal maintenance.
Adaptability: The inclusion of an increasing adaptor ensures a smooth transition between various chimney lining sizes—a crucial feature for achieving a seamless installation process.
Versatile Fuel Compatibility: Whether you use wood (with a moisture content under 20%), smokeless coal, gas, or oil, this installation kit can handle it all, making it a versatile solution for a wide range of heating systems.
Installation Process
Installation of the Pack 504 is straightforward, yet it requires careful attention to detail. Start by removing the existing chimney pot, ensuring all remnants of previous installations are cleared. Clean and prepare the area before fitting the 125mm top plate using the provided top clamp. Next, secure the nose cone in place, which not only adds a polished finish but also acts as a barrier against external elements. The increasing adaptor is then installed to bridge the size difference between a 100mm single wall flue and a 125mm flexible liner. Finally, affix the chimney notice plate in a prominent position to keep essential maintenance and safety instructions visible. Note: This kit should only be installed within a masonry enclosure. Non-masonry enclosures such as those using timber or plasterboard do not comply with the necessary safety regulations.
Maintenance and Safety
Regular maintenance is key to the longevity and efficiency of your chimney system. It is recommended that the chimney be inspected and cleaned at least once a year—more frequently if you use solid fuels. The chimney notice plate included in the kit serves as a visual reminder of maintenance requirements and can help prevent potential hazards. Always avoid using harsh chemicals or inappropriate tools when cleaning, and consider hiring a professional chimney sweep who is listed on HETAS for routine maintenance. This proactive approach ensures not only compliance with safety standards but also optimises the performance of your chimney.
Addressing Common Objections
Some customers may be concerned about the complexity of the installation process or the compatibility of the kit with their existing chimney system. However, the Pack 504 is engineered for ease of use. With all necessary components included and clear installation instructions provided, the kit minimizes the risk of error during setup. Additionally, its design caters to a variety of fuel types and chimney dimensions, making it both a flexible and robust solution. If you require additional accessories such as a cowl or terminal for enhanced weather protection or to deter birds, these can be easily sourced to complement your installation further.
Final Thoughts
The National Flues Pack 504 Installation Kit represents a valuable investment in the safety and efficiency of your chimney system. Its high-quality construction, complete set of components, and adherence to regulatory standards make it a standout choice for anyone in need of a reliable flue liner installation. Whether you are a seasoned professional or a motivated DIY enthusiast, this kit simplifies the installation process and ensures long-lasting performance. Choosing the Pack 504 means choosing peace of mind, quality, and efficiency in every installation.
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