What are radiator tails?
What are Radiator Tails? A Simple Guide to a Crucial Component
When you're looking at installing a new radiator or heated towel rail, you focus on the big parts: the radiator itself and the stylish valves you'll use to control it. But connecting these two main components is a small, often overlooked part that is absolutely essential for a secure, leak-free system: the radiator tail.
You might have heard your plumber mention them, or seen them included with a new set of valves. Understanding what they are and why they are so important is key to appreciating how your central heating system works. This simple guide from Elegant Radiators will explain exactly what radiator tails are, what they do, and answer the most common questions you might have about this crucial little component.
What Exactly Is a Radiator Tail?
A radiator tail (sometimes called a "radiator tail pipe") is a short, threaded piece of pipe that acts as the bridge between the radiator and the radiator valve. It has two distinct ends designed for two different jobs:
- The Male Threaded End: One end has a tapered thread (typically a ½" BSP thread). This is the end that screws directly into the inlet or outlet opening at the bottom of your radiator or towel rail.
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- The Nut and Olive End: The other end is designed to connect to the radiator valve. This is usually a compression fitting, consisting of a nut and a small brass or copper ring called an 'olive'. When you tighten the nut, it compresses the olive onto the tail, creating a perfect, watertight seal inside the valve.
In short, the radiator tail allows you to securely attach your valve to your radiator.
Why Are They So Important?
Without a radiator tail, you simply couldn't connect your valve. Its role is fundamental for two reasons:
- Creating a Secure Connection: It provides the correct type of fitting to join the radiator body to the valve body.
- Ensuring a Watertight Seal: When installed correctly with PTFE tape on the threaded end and the compression fitting properly tightened, the tail ensures that hot water flows from the pipe, through the valve, and into the radiator without a single drop escaping. A leak at this joint is a common issue in DIY installations where the tails haven't been sealed properly.
Types of Radiator Tails
While the basic function is the same, you will encounter a couple of different types:
- Standard Tails: These are the short, straight pieces of pipe that come as standard with most radiator valve sets. They are used in the vast majority of installations where the valve aligns neatly with the radiator inlet.
- Radiator Tail Extensions: These are essentially longer radiator tails. They are used when there is a larger-than-normal gap between where the pipework comes up and the radiator inlet. Using an extension avoids having to add extra, unsightly pieces of pipe and creates a much neater finish. They are available in various lengths to bridge different gaps.
Common Issues with Radiator Tails
Problems with radiator tails are almost always due to incorrect installation.
- Leaking from the Radiator Connection: If a leak appears where the tail screws into the radiator, it's because the threads were not properly sealed before installation.
- Leaking from the Valve Connection: If a leak appears from the large nut on the valve, it means the compression fitting is either not tight enough or the olive has been damaged or crushed by overtightening.
A professional plumber will know how to create the perfect seal every time, but it's a common stumbling block for inexperienced DIYers.
FAQ: Your Radiator Tail Questions Answered
Here are our answers to the most common questions about this small but mighty part.
Do new radiator valves come with radiator tails?
Yes, almost always. When you buy a pair of new radiator valves, they will come as a complete set which includes the two valve bodies and two matching radiator tails with their corresponding nuts and olives. You shouldn't need to purchase them separately unless you require a specific extension piece.
What size radiator tail do I need?
In the UK, the vast majority of radiator tails are a standard size. The end that connects to the valve is designed for 15mm pipework, and the threaded end that screws into the radiator is a ½" (half-inch) BSP thread. This is the standard size for virtually all modern radiators and towel rails sold by retailers like Company Blue.
Can I reuse my old radiator tails?
It is strongly recommended not to. The brass olive that creates the compression seal is a single-use component; once it has been compressed, it cannot be effectively reused and is very likely to leak. Since new valves come with new tails and olives, you should always use the new ones provided to ensure a perfect, leak-free seal.
What is a 'radiator tail extension' and when would I need one?
A radiator tail extension is simply a longer version of a standard tail. You would need one if your existing pipework is positioned too far away from the radiator inlet for a standard valve and tail to reach. Using an extension creates a neater and more secure join than trying to add a small, separate piece of copper pipe.
How do I fix a leak from a radiator tail?
If the leak is where the tail enters the radiator, the joint needs to be remade with fresh PTFE tape. If the leak is from the large nut on the valve, you can first try gently tightening the nut. If that doesn't work, the joint needs to be taken apart and reassembled, potentially with a new brass olive, as the old one may be damaged.
