
Delivery timing & exceptions
*For in-stock radiators ordered before 1pm on a working day. Orders after 1pm dispatch the next working day. Weekends, bank holidays and postcode exceptions can affect timing.
Ask us on WhatsApp 07949 448 870
Chat and WhatsApp daily, 7am–10pm UK time.
Free UK shipping on orders over £25 · 30-day returns: terms apply
Pair of Reducer for Radiator VALVES 15mm to 8mm
Convert 8mm microbore pipework to 15mm radiator valves with this pair of brass compression reducers. Ideal for UK central heating systems, towel rails, and radiator upgrades.
£4.79
Available to order
- Technical Attribute
- Product Specification Detail
- Valve-Side Fitting
- 15mm External Compression Joint
- Pipe-Side Fitting
- 8mm Internal Line Seat
- Material Composition
- Heavy-Duty Brass and Copper Components
✓ 1 year warranty. Terms apply.
Frequently bought together
Add optional accessories to your towel rail order. Check compatibility with your radiator and valve kit.
Product specifications
- Technical Attribute
- Product Specification Detail
- Valve-Side Fitting
- 15mm External Compression Joint
- Pipe-Side Fitting
- 8mm Internal Line Seat
- Material Composition
- Heavy-Duty Brass and Copper Components
- Joint Type
- Mechanical Compression Setup Only
- Package Contents
- 1 Pair (2x Radiator Valve Reducers to complete one radiator)
- Warranty
- 1 year; terms apply
About Pair of Reducer for Radiator VALVES 15mm to 8mm
15mm to 8mm Radiator Valve Reducer (Pair) – Microbore Pipe Adapter UK
Connect modern 15mm radiator valves to existing 8mm microbore pipework without the cost of a full system repipe. Many older UK central heating systems rely on narrow 8mm pipework, making it difficult to install updated heated towel rails or designer radiators. This pair of 15mm to 8mm radiator valve reducers allows you to adapt your current setup to fit modern heating fixtures.
Compatible with standard UK 15mm radiator valves and designed for 8mm microbore heating pipework.
Definition: This 15mm to 8mm radiator valve reducer allows 8mm microbore heating pipework to connect directly to standard 15mm radiator valves using a compression fitting.
Designed to fit inside standard 15mm compression valve assemblies, these components reduce the internal diameter to safely house an 8mm line. This provides a practical, reliable method for upgrading heated towel rails, vertical radiators, and column heating units while minimizing invasive plumbing work.
Key Benefits & Features
- Precise 8mm Reduction: Slides directly inside the compression inlet of manual or thermostatic radiator valves (TRVs) to adapt them for 8mm microbore pipework.
- High-Grade Metallic Build: Manufactured from premium brass and copper for excellent thermal conductivity and long-term resistance to central heating corrosion.
- Streamlined Visual Finish: Sits entirely flush within the compression end of the radiator valve, leaving no messy fittings or ugly extensions exposed after installation.
- Dual Material Compatibility: Works efficiently with traditional 8mm copper lines as well as 8mm plastic barrier piping.
Common Applications
These specialized microbore radiator valve reducers are ideal for:
- Replacing old radiators in properties with a legacy microbore system.
- Installing modern heated towel rails during bathroom renovations.
- Upgrading manual heating valves to modern, energy-efficient TRV bodies.
- Completing heating upgrades with minimal structural disruption to floors or walls.
Technical Data Table
| Technical Attribute | Product Specification Detail |
|---|---|
| Valve-Side Fitting | 15mm External Compression Joint |
| Pipe-Side Fitting | 8mm Internal Line Seat |
| Material Composition | Heavy-Duty Brass and Copper Components |
| Joint Type | Mechanical Compression Setup Only |
| Package Contents | 1 Pair (2x Radiator Valve Reducers to complete one radiator) |
Installation Guidance
This radiator valve reducer positions flush inside the compression end of the radiator valve. If you are fitting them onto flexible 8mm plastic barrier piping, always place a corresponding 8mm internal pipe stiffener/insert inside the plastic tube before tightening the outer nut to prevent the wall from warping over time.
A secure, watertight connection is achieved through mechanical tension as the olive compresses. For added security, professional installers generally recommend applying a light smear of jointing paste or a few wraps of plumbing PTFE tape to the joint threads during final assembly.
Delivery, returns & warranty
Check delivery details and the return policy. This product has a 1 year warranty; terms apply.
Questions about Pair of Reducer for Radiator VALVES 15mm to 8mm
What warranty comes with Pair of Reducer for Radiator VALVES 15mm to 8mm?
This product comes with a one-year warranty. Terms apply.






