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MPN: EXTK13ADJ90

Estimated Delivery: 3 - 5 Working Days

Grant High Level Internal Adjustable Extension 275–450

Grant High Level Internal Adjustable Extension 275–450


Regular price £167.09 Excl. VAT
£200.51 Incl. VAT
Sale price £167.09 Excl. VAT
£200.51 Incl. VAT
Regular price
*For business & Trade Accounts only.
Google Rating 5.0 out of 5 stars
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Key Information

Product Information

Grant High Level Internal Adjustable Extension 275–450

The Grant High Level Internal Adjustable Extension 275–450 is designed to provide additional flexibility when installing compatible Grant internal flue systems. With an adjustable length of 275-450mm, it allows installers to fine-tune the flue run where a fixed-length extension may not provide the exact fit required. The Grant White System Adjustable Extension 275-450mm 12-26kW is supplied with an extension and locking band and is primarily designed for use with compatible boilers up to 26kW. The adjustable design makes it a practical choice for high-level internal flue installations where precise positioning is important.

Adjustable Extension for Flexible Installation

With a length that can be adjusted between 275mm and 450mm, this extension can help accommodate different installation requirements without having to rely solely on fixed-length components. The included locking band helps secure the extension once the desired length has been established.

Available Adjustment Variants

The available range includes two adjustment options: 50-90mm and 90-200mm. These adjustment ranges provide additional flexibility when selecting compatible components for different installation configurations. For the 275-450mm extension itself, the product is primarily intended for compatible Grant boilers with outputs of up to 26kW.

Grant White System Compatibility

The extension forms part of the Grant White System and is designed for compatible internal flue arrangements. It provides installers with a convenient way to achieve the required flue length while maintaining a secure connection through the supplied locking band.

Key Features

  • Adjustable extension length of 275-450mm
  • Designed primarily for compatible boilers up to 26kW
  • Supplied with a locking band
  • Grant White System component
  • Provides flexibility when a fixed-length extension is unsuitable
  • Available adjustment variants of 50-90mm and 90-200mm
  • Designed for straightforward internal flue installation
  • Allows the flue length to be adjusted to suit the installation

Frequently Asked Questions

What is the adjustment range of the Grant High Level Internal Adjustable Extension?

The extension itself can be adjusted between 275mm and 450mm, allowing installers to fine-tune the overall flue length during installation.

Which boilers is the 275-450mm extension designed for?

The Grant White System Adjustable Extension 275-450mm 12-26kW is primarily designed for use with compatible Grant boilers with outputs of up to 26kW.

What adjustment variants are available?

The listed range includes 50-90mm and 90-200mm adjustment variants. These provide additional flexibility for selecting compatible components according to the requirements of the particular flue installation.

Why Choose Us

At JJ Building Materials, we're committed to supplying quality building products at competitive prices, backed by the service and expertise you'd expect from an established independent merchant. Whether you're a trade professional managing large-scale projects or a homeowner taking on a DIY renovation, we're here to help you find the right products for the job.

As part of the JJ Roofing Supplies Group, we build on decades of experience supplying construction materials across the UK. We've expanded beyond roofing to offer a growing range of building materials, including timber, insulation, landscaping products, plumbing supplies, flooring, doors, bricks, fencing, garden buildings and much more – all available to order online with nationwide delivery.

We work with many of the industry's leading manufacturers to bring you trusted products that meet the highest standards of quality and performance. Our team is passionate about providing excellent customer service, competitive pricing and a straightforward shopping experience from start to finish.

When you shop with JJ Building Materials, you can expect:

  • Competitive prices on leading brands and quality products.
  • Nationwide delivery across the UK
  • A constantly expanding range of building and landscaping materials.
  • Friendly, knowledgeable customer support.
  • A trusted business backed by the JJ Roofing Supplies Group.

Delivery

Every order is personally reviewed by our experienced team to ensure everything is correct before dispatch. We offer delivery from as little as the next working day on selected products, so please refer to the dark blue Estimated Delivery box above for the expected delivery timeframe for this item.

We work with trusted manufacturers and specialist delivery partners to ensure your order arrives safely and on time. You'll receive tracking details once your order has been dispatched, and if we need to confirm any delivery details, one of our team will contact you directly to keep everything running smoothly.

Roof Tiles & Fittings:

We recommend ordering an additional 10% of roof tiles to allow for any breakages that may occur during delivery or handling. Roof tiles are naturally fragile, and having a few extra on site helps prevent delays and ensures your roofing project can be completed without interruption.

Multiple Products from the Same Supplier

If you're ordering multiple products from the same supplier, your order will be dispatched together once all items are ready. This means the longest lead time will apply.

If you need part of your order sooner, please call us on 01202 113233. We can arrange a split delivery, although an additional shipping charge will apply.

Grant High Level Internal Adjustable Extension 275–450

£167.09

Can I collect this product from a local branch?

Absolutely. Check availability at your nearest branch during checkout or contact us directly.

Do you offer bulk pricing or trade discounts?

Yes, we offer competitive rates for trade customers and bulk orders. Contact our team for a tailored quote.

What if the product arrives damaged?

Please notify us within 48 hours of delivery. We’ll arrange a prompt replacement or refund as needed.

How fast is the delivery time?

Most items are delivered within 2–5 working days, depending on stock and location. Some products may take longer times.

What is the Return Policy?

We accept most returns within 14 days of delivery, provided the items are unused, in their original packaging, and in resalable condition. Please contact our customer service team to arrange a return or discuss any concerns.