Insulation Back Filler - Ø 150
At a Glance
- - Designed for effortless chimney back filling with vermiculite
- - Compatible with MI-FLEX 316 and 904 flue liners
- - Manufactured in premium 316L stainless steel for longevity
- - Fully compliant with Building Regulations Document J
- - Engineered for solid fuel, gas, oil and smokeless coal appliances

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 Mi Flues Screw-FIX Insulation Back Filler - Ø 150 is a cutting-edge solution for efficiently back filling your chimney with vermiculite, designed specifically for use with Screw-Fix pot hanging cowls and MI-FLEX flue liners. This premium accessory is engineered to work seamlessly with both MI-FLEX 316 and 904 flexible flue liners, ensuring a cohesive and fully functional chimney system. Compliant with Building Regulations Document J, this product can be used with appliances up to 600°C (T600 designation) and is suitable for wood (less than 20% moisture), smokeless coal, gas, and oil.
Our Screw-Fix accessories are crafted to facilitate the installation and maintenance of multi-fuel flue liners, housed completely within masonry chimneys—a non-masonry enclosure like timber or plasterboard is not permissible. Regular chimney sweeping and maintenance are critical, especially for solid fuel appliances, and should be conducted by a certified professional. Avoid using chemical cleaners or mild steel tools on stainless steel chimneys.
We advise sweeping twice annually: at the end of the heating season and before the start of the next season.
SKU: 25-150-VBF
Technical Specifications | |
---|---|
SKU | 25-150-VBF |
Diameter | u00d8 150 |
Material | 316L Stainless Steel |
System | MI-FLEX Accessories MF20 |
Certifications | CE / HETAS |
Fuel Compatibility | Wood (less than 20% moisture), Smokeless Coal, Gas, Oil |
Temperature Rating | Up to 600u00b0C (T600 designation) |
Delivery Information +
We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Thursday, April 3rd. 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
At National Flues, we highly recommend the Mi Flues Screw-FIX Insulation Back Filler. This innovative product simplifies the process of back filling your chimney with vermiculite while ensuring compliance with Building Regulations. We are rarely beaten on price, offer reliable delivery, and cater to both retail and trade customers nationwide.
The Mi Flues Screw-FIX Insulation Back Filler is designed to simplify the back filling of chimneys with vermiculite, ensuring proper insulation and compliance with regulations when using flexible flue liners.
National Flues is a trusted supplier of fireplaces and flues in the UK, dedicated to providing high-quality products at competitive prices, with reliable delivery and excellent customer service for both retail and trade customers.
