IL - Adjustable Length - 457mm (18in) - Ø 125
At a Glance
- Adjustable length design offering effective installation lengths between 75mm to 356mm
- Robust twin wall insulated construction for enhanced safety
- Durable aluminium liner with a corrosion-resistant zalutite outer casing
- Certified to CE and BS EN 9001:2008 standards
- Suitable for both internal and external applications under dry conditions
- Designed for naturally aspirated domestic gas-fired 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 IL Adjustable Length 457mm (18in) Ø 125 Gas Vent is a twin wall insulated gas vent system, meticulously designed for naturally aspirated domestic gas-fired appliances. It’s engineered to perform optimally under negative pressure and dry conditions, supporting flue gas temperatures not exceeding 250°C. This configuration includes an aluminium liner paired with a zalutite outer casing, separated by a 6mm air gap for superior insulation.
Its versatility makes it suitable for both internal and external applications, though it’s not designed for condensing and positive pressure environments. Available in three sizes – 100mm, 125mm, and 150mm diameters – this product adapts to various installation needs. Renowned for its durability and efficiency, the IL Gas Vent System is your go-to solution for secure and reliable flue performance.
SKU: 24-125-16
Technical Specifications | |
---|---|
SKU | 24-125-16 |
Product Name | IL - Adjustable Length - 457mm (18in) - u00d8 125 |
Design Standard | EN 1856-1 T250 N1 D Vm L11030 0(50) |
System | IL |
Adjustable Length | 457mm (18in) |
Available Diameters | 100mm, 125mm, 150mm |
Inner Material | Aluminium |
Outer Material | Zalutite (zinc-aluminium coated steel) |
Fuel Compatibility | Gas |
Approvals | CE, BS EN 9001:2008 |
Temperature Limit | Up to 250u00b0C |
Distance To Combustibles | 50mm (2 inches) |
Warranty | 5 year conditional warranty |
Joint Method | Push fit and twist lock |
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.
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National Flues Ltd Verdict
The IL Adjustable Length 457mm (18in) Ø 125 Gas Vent is a prime choice for both trade and retail customers. Its reliability and quality have stood the test of time, making it a trusted solution for over 25 years. With National Flues, enjoy unbeatable prices and dependable nationwide delivery.
The IL Adjustable Length Gas Vent is designed to provide a reliable and efficient venting solution for naturally aspirated domestic gas-fired appliances.
National Flues is a leading supplier of fireplaces and flue systems across the UK, known for competitive pricing, reliable delivery, and exceptional service to both retail and trade customers.
