Non-concentric increaser 3 diameters - Ø 650
At a Glance
- Premium 316L Stainless Steel construction for exceptional durability
- Three-step diameter increaser design optimising flue performance
- Non-concentric design to effectively prevent condensate pooling
- High-pressure sealing gasket (P1/H1) for secure, leak-resistant joints
- CE approved and compliant with EN 1856-1 standards
- Compatible with both high and low temperature, condensing and non-condensing systems
- Secure push-fit jointing system with a Locking Band for ease of installation

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
Our Non-Concentric Increaser Ø 650 is a highly efficient solution designed to increase the diameter of your flue system by three steps. Made from premium 316 grade stainless steel, it comes with a high-pressure sealing gasket P1/H1, ensuring robust performance in various environments. The SWPro modular single wall flue system is versatile, suitable for both high and low temperature, non-condensing and condensing applications with positive and negative pressure.
Perfect for boilers, ovens, ventilation systems, and as a chimney shaft liner, this increaser is crafted to meet the highest standards. Approved and CE marked, installation is straightforward with a push-fit jointing system secured by a Locking Band. Ensure a 50mm clearance from any combustible materials during installation.
SKU: 3-650-204
Technical Specifications | |
---|---|
SKU | 3-650-204 |
Diameter | u00d8 650 |
Material | 316L Stainless Steel (inner) |
Sealing | High-pressure gasket P1/H1 |
Clearance | 50mm from combustibles |
Approvals | CE marked, EN 1856-1 compliant |
Applications | Boilers, ovens, ventilation systems, chimney shaft liners |
System | SWPro modular single wall flue |
Delivery Information +
We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Tuesday, April 29th. 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 Non-Concentric Increaser Ø 650 is a superb addition to any commercial flue system. Its exceptional construction and high-performance adaptability make it an essential choice. Plus, with National Flues, you benefit from unbeatable prices and nationwide delivery for both retail and trade customers.
The Non-Concentric Increaser Ø 650 is used to increase the diameter of flue systems by three steps, ideal for preventing condensate pooling in inclined runs.
National Flues is a leading supplier of fireplaces and flues, serving both retail and trade customers across the UK with unbeatable prices and reliable delivery.
