DM54 - 300mm ID 545mm square support block
At a Glance
- High-quality pumice construction for superior insulation
- Designed for a 300mm ID and 545mm square installation
- Integral part of the Isokern DM block system
- Dual-wall design to preserve flue gas temperatures and prevent external heat transfer
- HETAS Approved and CE marked for enhanced safety and reliability

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 DM54 - 300mm ID 545mm square support block, part of the Isokern DM block system, offers a superior solution for your chimney needs. This high-quality system chimney features a dual-wall design that expertly maintains flue gas temperatures and prevents heat transference to the outer casing. This separation of the inner and outer components not only allows for thermal movement but also reduces the risk of cracking, leaking, or staining.
The DM54 is simple and quick to build, making it a convenient choice for various applications. Available in three outer casing sizes - DM36, DM44 & DM54, this system is suitable for use with inserts, stoves, open fires, and cookers burning wood, solid fuel, oil, or gas (excluding condensing appliances such as Biomass & Pellets). Constructed from pumice, a natural insulator, this support block ensures that flue gases quickly reach their optimum temperature, aiding in the performance and efficiency of your heating appliance.
The DM54 keeps the chimney warmer for longer, reducing condensation and soot build-up. HETAS Approved and CE marked, the Isokern DM chimney system ensures top-notch safety and performance. For the best results, always refer to the installation instructions provided.
SKU: 59-129043
Technical Specifications | |
---|---|
SKU | 59-129043 |
Internal Diameter | 300mm |
External Dimension | 545mm square |
Material | Pumice |
Outer Casing Options | DM36, DM44, DM54 |
Warranty | 10 Years |
Compliance | HETAS Approved, CE marked |
Fuel Compatibility | Wood, Solid Fuel, Oil, Gas (excluding condensing appliances such as Biomass & Pellets) |
System | Dual Wall Chimney System |
Distance To Combustibles | 0 on straights; 38mm on offsets on DM System |
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 DM54 - 300mm ID 545mm Square Support Block stands out for its exceptional quality and reliability. At National Flues, we deliver nationwide and cater to both retail and trade customers. Rarely beaten on price and committed to reliable delivery.
The DM54 - 300mm ID 545mm Square Support Block is designed to facilitate efficient and safe chimney construction, maintaining flue gas temperatures and preventing heat transference, suitable for a variety of heating appliances.
Isokern specialises in high-quality chimney solutions, offering innovative and efficient products designed to improve heating appliance performance and safety. Trusted for their reliability and insulation properties, Isokern products are a top choice in the industry.
