Radiator valves might not be the most noticeable part of your heating setup, but choosing the right one affects both how your radiator performs and how it looks in the room.
From thermostatic to manual, angled to straight, the right choice depends on your pipework, your radiator and how much control you want over your heating.
This guide breaks down the different types of radiator valves and how to choose the right option for your home.
Why don’t radiators come with valves?
Radiators are usually sold without valves and there’s a good reason for that.
Every home’s pipework layout is different. Some pipes come through the floor, others from the wall, and some run neatly along skirting boards. The right valve depends on how those pipes connect to your radiator.
Keeping valves separate means you can choose the correct shape for your pipework, match the finish to your radiator and room style and decide how much control you want over the heat output.
What does a radiator valve actually do?
In simple terms, a radiator valve controls how much hot water flows into your radiator. More water flowing through the radiator increases the heat output. Reducing that flow lowers the temperature in the room.
Radiators typically use two valves:
Control valve – This adjusts the heat output from the radiator.
Lockshield valve – This balances the system so that water flows evenly through all the radiators in your home.
They may be small components, but they play an important role in keeping your heating system working efficiently.
Manual or thermostatic radiator valves – what’s the difference?
One of the first choices most people make when selecting valves is whether to use manual valves or thermostatic radiator valves.
Manual radiator valves
Manual valves are the simplest and most traditional option. You turn the valve by hand to increase or decrease the flow of hot water, adjusting the radiator’s heat output directly. There are no sensors or automatic controls involved.
They work well if you:
- Use a central thermostat to manage your home’s temperature
- Prefer a simple, straightforward setup
- Want a compact valve for a minimalist radiator design
Because manual valves tend to be smaller than thermostatic valves, they can suit sleeker radiator styles particularly well also.
Thermostatic radiator valves (TRVs)
Thermostatic radiator valves - often shortened to TRVs - automatically regulate the heat output from your radiator.
A built-in sensor measures the temperature in the room. When the room reaches the temperature you’ve set, the valve reduces the flow of hot water into the radiator.
This helps maintain a consistent room temperature without needing constant manual adjustment.
People often choose TRVs because they:
- Help reduce wasted energy
- Maintain steady room temperatures
- Allow better control of heating in different rooms
When installed correctly, they can also help improve overall heating efficiency. TRVs are always paired with a lockshield valve on the opposite side of the radiator.
What is a lockshield valve?
Every radiator uses a lockshield valve, although it’s usually adjusted only during installation.
Its role is to control the water leaving the radiator and help balance the heating system. By adjusting the flow across each radiator, installers ensure that all rooms heat up evenly.
Once set, the lockshield valve is normally left untouched unless the system is being rebalanced.
Straight, angled or corner valves — which do you need?
Choosing the correct valve shape depends on how your pipework connects to the radiator.
Angled valves
Angled valves are the most common type.
They’re used when pipes come from the floor or wall and need to turn 90° to connect with the radiator inlet.
Corner valves
Corner valves sit closer to the wall and create a neater appearance.
They’re often chosen for design reasons, particularly with modern radiators where a cleaner look is preferred.
Straight valves
Straight valves are used when the pipe runs directly into the radiator inlet without needing to turn.
If your pipework lines up directly with the radiator connection, this is usually the correct option.
A quick pipework guide
If you’re unsure which valve shape you need, your pipework usually provides the answer.
As a simple rule of thumb:
- Pipes coming from the wall into side inlets usually require angled or corner valves
- Pipes coming from the floor into bottom inlets generally use straight valves
- Pipes coming from the floor into side inlets will typically need angled valves
In short, if the pipe needs to turn to reach the radiator, an angled valve is usually the right choice.
If you’re still unsure, taking a quick photo of your pipework before ordering can make it much easier to confirm the correct option.
What size radiator valve do I need?
In most UK homes, radiator valves are 15mm. This matches the standard size used for copper central heating pipes.
Other sizes do exist - typically ranging from 8mm to 28mm - but 15mm is by far the most common. If your pipework is slightly different, adapters are often available.
When in doubt, measuring the outside diameter of your pipe before ordering will give you the clearest answer.
Traditional or modern valve styles
Radiator valves may be small, but they’re still visible. Choosing the right finish helps your heating feel intentional and stylish.
Traditional valves tend to suit:
- Cast iron radiators
- Period homes
- Heritage-style interiors
These designs often feature decorative tops and classic finishes such as brass or bronze.
Modern valves work well with:
- Contemporary panel radiators
- Vertical radiators
- Minimal interiors
Slim profiles, clean lines and finishes like matt black, brushed brass and chrome help them blend naturally with modern spaces.
It’s a small detail but one that can make a noticeable difference to the overall look of a room.
Radiator valves might be small components, but they play an important role in how your heating system performs.
Choosing the right type, shape and finish helps your radiators work efficiently while ensuring they fit naturally within the design of your space. And when everything is properly matched - pipework, valves and radiator - your heating system simply works the best way it should.
Ready to choose your valves?
Explore our range of radiator valves to find the right shape, finish and control for your setup.
Or, if you're still weighing up your options, this guide could help: Find the Right Radiator Size for Your Space.
