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DM36 - 360mm square x 250mm high access casing (59-130712)

National Flues proudly presents the DM36 360mm square x 250mm high access casing, a premium chimney accessory engineered for optimal flue gas heat retention and efficiency. This top-quality, double-wall access casing, crafted from natural pumice, is ideal for stoves, open fires, and cookers, offering excellent thermal performance while minimising heat loss. Read more...
Now only £62.99
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At a Glance

  • Constructed from natural pumice for superior insulation
  • Double-wall design reduces thermal stress and prevents leaks
  • HETAS approved and CE marked for industry-leading safety standards
  • Versatile design suitable for stoves, open fires, and cookers (wood, oil, solid fuel, gas)
  • Features a 150mm internal diameter access hole for easy inspection and maintenance

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: sales@nationalflues.com

The DM36 360mm square x 250mm high access casing is part of the Isokern Double Module (DM) block system, renowned for its exceptional thermal insulation and durability. Constructed from natural pumice, this casing maintains optimal flue gas temperatures while preventing heat transference to the outer casing. The unique double-wall structure allows for thermal movement, minimising the risk of cracks and leaks.

Quick and easy to install, the DM36 is suitable for a wide range of heating appliances including stoves, open fires, and cookers using wood, solid fuel, oil, or gas (excluding condensing appliances like Biomass and Pellets). Approved by HETAS and CE marked, the Isokern DM system ensures superior performance and safety, keeping your chimney warmer for longer and reducing condensation and soot build-up.

SKU: 59-130712

Delivery Information* +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Monday, November 17th. This is based on current lead times. Bear in mind that it is a busy time of year. If you need a product delivered by a specific time in the next 7 days, then please give us a call on 01670 206 999. Visit our Shipping Information page for more information.

About National Flues Ltd +

We began over 30 years ago as a fireplace shop in the North East. We now supply hundreds of trade professionals and thousands of retail customers, all across the UK, every month. We are still a family owned business, lead by the MD Neil, and always try our best to deliver the best possible experience. We also price match, so give us a call if you find this cheaper and want to buy from us. Visit our about us page to read a bit more.

Technical Specifications
Dimensions360mm square x 250mm high
Internal Access Hole150mm diameter
MaterialNatural Pumice
CertificationHETAS Approved, CE marked
Warranty10 Years
Suitable ForStoves, open fires, cookers (wood, oil, solid fuel, gas; excluding condensing appliances)
DesignDouble-wall for enhanced thermal performance
• Ensure correct clearance from combustibles (0mm on straights; 38mm on offsets with DM System) • Follow the installation guides provided by National Flues for safe and efficient setup • Pre-inspect the chimney structure and consult a professional installer if necessary • Use proper tools and adhere to manufacturer recommendations for mounting and sealing • Always observe safety warnings and maintenance guidelines to prolong the life of the casing

The DM36 is suitable for use with stoves, open fires, and cookers burning wood, solid fuel, oil, or gas. It is not suitable for condensing appliances, including Biomass and Pellets.

Pumice is a natural insulator, which helps flue gases reach their optimum temperature quickly and maintain it longer. This enhances the heating appliance’s performance and reduces the likelihood of condensation and soot build-up.

Yes, the Isokern DM36 is HETAS Approved and CE marked, ensuring it meets high safety and performance standards.

Yes, the DM36 is suitable for use with gas appliances, provided they are not condensing types like Biomass and Pellets.

The DM36’s double-wall design allows for thermal movement, which reduces the risk of cracking, a common cause of leaks in chimneys.

The DM casing is available in three sizes: DM36, DM44, and DM54.

Installation instructions for the DM36 can be found in the product guides and documentation provided by National Flues.

 

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