Angled vs Straight Radiator Valves: What’s the Difference and Which Should You Choose?

Radiator valves may be small, but they play a crucial role in your home’s central heating. These little fittings control the flow of hot water into your radiators, letting you regulate the heat in each room or even turn a radiator off for maintenance. In the UK, where most homes use gas central heating with wall-mounted radiators, picking the right type of radiator valve ensures your heating system works efficiently and looks neat. The two main shapes of valves are angled and straight. In this post, we’ll explain what radiator valves do, the differences between angled and straight valves, when to use each type (e.g. pipes coming from the wall vs the floor), how to tell them apart visually, and some tips on choosing the right valves for your home. We’ll keep it friendly and jargon free so any homeowner can follow along.

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What Do Radiator Valves Do?

Every radiator in a wet central heating system has valves that control the hot water flow in and out. By adjusting a valve, you can increase or decrease how much hot water enters the radiator, thus controlling how warm the radiator (and the room) gets. Typically there are two valves on each radiator:

• Control valve (manual or thermostatic): This is the valve you turn (or that has a thermostat head) to set the radiator’s heat level. A manual valve works like a tap you open it to let water in or close it to shut the radiator off. A thermostatic radiator valve (TRV) goes a step further: it automatically adjusts the flow based on room temperature, letting you set a desired level and saving energy by preventing overheating.
• Lockshield valve: The valve on the other side, often covered with a cap. This one is usually left fully open or slightly throttled to balance the system (it controls the return flow). You generally won’t adjust this day-to-day.

In short, radiator valves allow independent control of each radiator’s heat. This means you can, for example, keep bedrooms cooler while living areas stay cozy, helping with comfort and energy efficiency. Now that we know their purpose, let’s look at the two main styles of valve fittings: angled and straight.

Angled vs Straight Radiator Valves: What’s the Difference?

Radiator valves come in different shapes to suit how your pipework is arranged. Angled and straight valves refer to the shape of the valve and the direction it connects to the radiator and pipe:

• Straight radiator valves have no bends or curves at all. The valve’s inlet and outlet are in a straight line. Water flows directly through in a straight path.
• Angled radiator valves have a 90-degree elbow bend in the body, forming an “L” shape. This means the inlet (connected to the pipe) is at a right angle to the outlet (connected to the radiator). Essentially, water makes a right-angle turn inside an angled valve.

Functionally, there’s no difference in how they control water flow – both types can be either manual or thermostatic and serve the same purpose of turning the radiator on/off or up/down. The critical difference is the installation geometry: the shape determines how the valve connects your pipe to the radiator. Choosing the wrong shape would make the pipe hookup awkward or impossible.

Straight Radiator Valves (Linear Valves)

Design & Appearance: A straight radiator valve is, as the name implies, straight. The connectors on both ends line up; there is no 90° bend in the body. One end connects into the radiator inlet, and the other end attaches to the pipe, forming a continuous straight line. Visually a straight valve often looks like a small inline tap sticking out of the radiator’s bottom or side.

Typical Use Cases: Straight valves are used when the pipework can connect to the radiator in a straight line without bending. This usually means the pipe comes from directly below (up from the floor) into the bottom of the radiator. For example, many towel warmers and bathroom ladder radiators have valve connections at the bottom, pointing downward if your pipes come up through the floor to meet them, straight valves will allow the water to flow straight up into the radiator. Straight valves are perfect for bottom-fed radiators with floor piping because they make a clean vertical connection. They are also common for some modern designer radiators and column radiators that have underside connections.

Another situation for straight valves is if pipes run horizontally along a wall at the same height as the radiator inlet. In some older UK homes, you might see exposed pipes running along the skirting board to the radiator. If those pipes go straight into the radiator’s side inlet, a straight valve can connect them directly without turning.

Summary: If your pipework and radiator inlet align on the same level and line, a straight valve is the right choice. A common example is pipes coming up from the floor into the bottom of a radiator here a straight valve provides the simplest, neatest connection.

Angled Radiator Valves (90° Valves)

Design & Appearance: An angled radiator valve has an obvious right-angle shape in its body. One part of the valve attaches to the radiator, and the other part connects to the pipe at a 90° angle. When installed, an angled valve often looks like an elbow coming out of the radiator. The head of the valve (the part you turn) usually sticks out to the side of the radiator, and the pipe comes in from another direction (from below or from behind).

Typical Use Cases: Angled valves are extremely common in UK homes because they suit the typical way radiators are plumbed. Use an angled valve whenever your pipes and radiator inlets meet at a right angle or need a turn. Some scenarios include:

• Pipes coming up from the floor to a radiator’s side inlet: Most standard panel radiators have connections on the sides at the bottom. If your pipes come through the floor, they will need to turn 90° to enter the radiator’s side. An angled valve is designed for exactly this it allows vertical pipes from the floor to connect into horizontal radiator connections. This is one of the most common setups in the UK.
• Pipes coming out of the wall to a radiator’s bottom inlet: In modern installations or when trying to hide pipework, pipes may be routed inside the wall and poke out directly behind the radiator. To connect a pipe coming horizontally out of a wall into the bottom of a radiator (which points downward), you need a 90° turn upward. An angled valve can be oriented to do this (the valve will turn the flow from horizontal to vertical). This keeps the pipework neat and mostly hidden.
• Any situation with limited space or an obstacle: Sometimes radiators are very close to walls or in tight corners. Angled valves can give flexibility by changing the direction of the pipe connection, which can help fit a valve into a cramped spot.

Summary: If your pipe comes from a direction that isn’t in line with the radiator inlet, you’ll likely need an angled valve. Whenever a 90° change of direction is required such as connecting floor-uprising pipes to side inlets, or wall-emerging pipes to bottom inlets an angled valve is the solution. In fact, angled valves are the most commonly used type today because they are versatile for connecting radiators in various configurations.

What About Corner Valves?

You might also hear about corner radiator valves. A corner valve is essentially a special variant of an angled valve. It still has a 90° bend internally, but the orientation is rotated so that the valve head sits on top of the elbow rather than sticking out. Corner valves are typically used when pipes come out of the wall and you want the valve head to point upwards (vertical) rather than sideways, giving a super tidy look next to the radiator. In practice, corner valves do the same job as angled valves – the choice between angled vs corner often comes down to aesthetics and how you prefer the valve to face. For the scope of this article, just know that corner valves = a type of angled valve for wall pipework, offering a neater appearance because the control knob points up or down instead of out.

When to Use Angled vs When to Use Straight Valves

Choosing between an angled or straight radiator valve mostly depends on where your pipes come from and where the radiator’s valve connections are. Here are some general guidelines for common UK heating setups:

• If your pipework comes up from the floor and your radiator has bottom connections (pointing downward) use straight valves. The pipe will go straight up into the radiator. This is typical for things like floor-mounted towel rails or some vertical designer radiators. A straight valve gives a clean vertical run from the floor into the radiator inlet.
• If your pipework comes up from the floor and your radiator has side connections use angled valves. This scenario is very common for standard wall-hung radiators (the ones with valve openings on the sides at the bottom). The pipe needs to come up and then turn into the radiator’s side, so an angled valve makes that 90° turn.
• If your pipework comes out from the wall and the radiator has bottom connections use angled valves (or corner valves). Here the pipe is horizontal coming out of the wall and the radiator inlet points down, so you must turn the flow upward into the rad.
• If your pipework comes out from the wall and the radiator has side connections typically use a corner valve (or an angled valve rotated appropriately). Corner valves are preferred for a neat side connection when pipes are in the wall.
• If your pipework runs along the wall surface (exposed) to the radiator – depending on alignment, a straight valve might connect directly (e.g., pipes along the skirting entering a side inlet).

In summary, angled valves are the go-to for most configurations (floor to side, wall to bottom, etc.) because UK radiators often involve a 90° connection. Straight valves are used when no turn is needed, such as floor-to-bottom connections (common for towel rails). A handy rule of thumb often quoted by plumbers: “If your pipes come from the wall, you’ll need angled valves; if they come from the floor into bottom outlets, go for straight valves.” Just remember to also consider where the radiator’s valve inlets are side versus bottom as described above.

How to Identify Angled vs Straight Valves Visually

Diagram: A simple illustration of a straight valve vs an angled valve in use. On the left, a straight valve connects a pipe coming up from the floor directly into the bottom of a radiator. On the right, an angled valve makes a 90° turn to connect a pipe emerging from the wall into the radiator. In both cases, the valves control water flow, but their shapes allow different pipe orientations.

It’s usually quite easy to tell an angled valve from a straight valve just by looking at it:

• A straight valve will have a straight-line profile. When installed, the pipe and the radiator connection appear to be in one continuous line with the valve in between.
• An angled valve will clearly form a right angle (L-shape) between the radiator and the pipe.

In other words, straight valves have no bend, whereas angled valves have an elbow shape. If you’re holding the valves in your hand, align the end that goes into the radiator and the end that connects to the pipe do they form a straight line or a right angle? That’s the giveaway.

Tips for Choosing the Right Radiator Valve for Your Home

• Check where your pipework comes from: Note whether your pipes come out of the wall or up from the floor where your radiator will be. This will narrow down your valve shape options.
• Identify your radiator’s inlet positions: Most UK radiators have two inlet ports at the bottom, one on each side. Some modern radiators (like vertical or designer models) might have central bottom inlets or other configurations.
• Match the valve to the pipework and inlet:
  • Floor + bottom inlet = Straight valve
  • Floor + side inlet = Angled valve
  • Wall + bottom inlet = Angled (or Corner) valve
  • Wall + side inlet = Corner (or angled) valve

  If you’re replacing an existing valve, it’s safest to buy the same type (angled/straight) that you currently have, since your plumbing is already set up that way.

• Consider special cases (towel radiators, etc.): Most heated towel rails are bottom-fed; if the pipes come from below, they typically require straight valves. If the pipes come from the wall, use angled (often oriented vertically for a tidy look).
• Decide between manual vs thermostatic: TRVs have a built-in thermostat to maintain room temperature; manual valves require you to adjust flow yourself. In the UK it’s common to use TRVs on most radiators (except the one in the room with the wall thermostat).
• Ensure the valve size matches your pipes: Most UK homes use 15 mm pipes and 15 mm valves. Some systems use 10 mm (or 8 mm) microbore; large cast-iron radiators might use 22 mm feeds. The radiator side is typically a standard 1/2” BSP thread.
• Choose a style and finish that suits your décor: Options include chrome, brushed nickel, white, black, brass, anthracite, etc. In bathrooms or damp areas, pick corrosion-resistant finishes.
• Buy valves as a pair (and don’t forget the lockshield): Valves are usually sold in pairs one control valve and one lockshield in matching shape and finish.
• Consult a professional if unsure: A heating engineer or knowledgeable store staff can confirm the correct type from a quick look at your setup.

By keeping these tips in mind, you’ll ensure you get the correct valves that both fit your system and complement your home. The right radiator valves will make your installation look professional and allow you to efficiently control your heating.

Final Thoughts

Radiator valves might not be the first thing you think about when upgrading your heating, but choosing the appropriate type (angled vs straight) is essential for a hassle free install and a neat finish. To recap, angled valves have a 90° bend and are used whenever your pipes need to turn into the radiator (common for floor-fed standard radiators and any wall-fed connections). Straight valves have no bend and are used when the pipework goes straight in (common for floor-to-bottom connections like towel rails). Visually, it’s the difference between an “L”-shaped fitting and a straight-line fitting. Always match the valve type to your pipe direction and radiator inlet position.

Once the functional aspect is sorted, you can enjoy picking a style, finish, and whether you want the convenience of thermostatic control. Replacing old valves with new ones can refresh the look of your radiators and improve heating control. Just remember: no amount of style can compensate if the valve is the wrong type for your piping, so get that right first!

We hope this guide has demystified the difference between angled and straight radiator valves and given you the confidence to choose the right valves for your UK home. With the correct valves in hand, you’ll be one step closer to a toastier, well-tuned heating system, without any unsightly pipework twists or installation drama. Stay warm! 

Radiator Valve Selection Guide

Radiator Valve FAQ: Angled vs Straight Explained

1. What does a radiator valve do in central heating?

   A radiator valve controls the flow of hot water into your radiator, allowing you to adjust room temperature or turn off a radiator without affecting the whole system.

2. What is the difference between angled and straight radiator valves?

   Straight valves connect pipes in a straight line, while angled valves have a 90° bend for pipes that meet the radiator at a right angle.

3. When should I use angled radiator valves?

   Use angled valves if your pipes come from the floor into a side connection or from the wall into the bottom of the radiator.

4. When should I use straight radiator valves?

   Straight valves are ideal when pipes rise from the floor directly into the bottom of a radiator, such as towel rails or some vertical radiators.

5. What are corner radiator valves?

   Corner valves are a type of angled valve where the control head sits vertically instead of sticking out sideways, perfect for wall-fed pipes with a neat finish.

6. Do angled and straight radiator valves affect heating efficiency?

   No. Both types control water flow equally well. The choice depends on your pipework direction and radiator inlet position, not efficiency.

7. Can I replace angled valves with straight ones?

   Only if your pipework and radiator inlets align correctly. Otherwise, you must use the same type (angled or straight) that matches your setup.

8. Do towel radiators need angled or straight valves?

   Most towel rails are bottom-fed. If pipes come from the floor, use straight valves; if pipes come from the wall, use angled or corner valves.

9. What size radiator valve do I need in the UK?

   Most UK homes use 15mm valves to fit 15mm copper pipes. Older systems may use 10mm or 8mm microbore, while larger radiators may require 22mm.

10. Should I choose manual or thermostatic radiator valves (TRVs)?

    Manual valves let you adjust flow manually, while TRVs automatically regulate room temperature, saving energy and improving comfort.