TWPro MB - Single Wall to Twin Wall Increaser - Ø 175-Ø 200
At a Glance
- - Premium dual stainless steel construction (316L inner, 304 outer with high-temperature black finish)
- - Suitable for solid fuel, gas, and oil appliances
- - HETAS Approved and CE marked for safety and compliance
- - Includes a secure Locking Band for easy installation
- - Provides a safe 50mm clearance from combustibles

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 TWPro MB - Single Wall to Twin Wall Increaser is an essential component for your chimney flue system, especially when upgrading from a 175mm single wall pipe to a 200mm twin wall insulated chimney. Designed for use with solid fuel, gas, and oil appliances, including wood stoves, gas coal effect fires, and boilers, this increaser ensures optimal performance and safety. Constructed with a durable outer skin of 304 grade stainless steel at 0.4mm thickness, it features a high-temperature black finish for added durability.
The inner skin, made from 316 grade stainless steel, also at 0.4mm thickness, ensures longevity. The rockwool insulation boasts a density of 200kg/m³, providing excellent thermal protection. Fully welded parts and a safe distance of 50mm to combustibles make installation straightforward and secure.
The TWPro MB Increaser is HETAS Approved and CE marked, with designation numbers EN1856-1 T600 N1 W V2 L50040 G50 and EN1856-1 T200 P1 W V2 L50040 O20, ensuring it meets the highest safety and quality standards. Installation is simplified with the included Locking Band, ensuring a secure and reliable fit.
SKU: 37-175-002
Technical Specifications | |
---|---|
SKU | 37-175-002 |
Size | u00d8 175 to u00d8 200 |
Inner Construction | 316L Stainless Steel (0.40mm thick) |
Outer Construction | 304 Stainless Steel (0.40mm thick, High Temperature Black Coated) |
Insulation | Rockwool with density of 200kg/mu00b3 |
Approvals | HETAS / CE |
Distance To Combustibles | 50mm |
System Compatibility | TWPro Black |
Designation Numbers | EN1856-1 T600 N1 W V2 L50040 G50 and EN1856-1 T200 P1 W V2 L50040 O20 |
Delivery Information +
We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Tuesday, April 8th. 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.
Compatible and other products that may be of interest...
National Flues Ltd Verdict
The TWPro MB - Single Wall to Twin Wall Increaser is a top-quality product that ensures a seamless transition between different pipe sizes. HETAS Approved and CE marked, this increaser is built to last with premium materials and expert construction. Whether you're in retail or trade, you'll appreciate our reliable nationwide delivery and exceptional prices. Secure your order today with confidence.
The TWPro MB Increaser is used to seamlessly connect 175mm single wall pipes to 200mm twin wall insulated chimneys, ensuring safe and efficient operation across various heating appliances.
National Flues is a leading supplier of high-quality fireplaces and flue systems in the UK, offering competitive prices, reliable nationwide delivery, and exceptional service to both retail and trade customers.
