What do radiator valves do?

Radiator valves control the flow of hot water into and out of a radiator, which affects how warm it gets. Most radiators use two valves: one to control or regulate heat on the inlet side, and another on the return side that helps balance the system so multiple radiators heat evenly.

What’s the difference between TRVs and manual radiator valves?

A TRV (thermostatic radiator valve) has a sensor that reacts to the room temperature and automatically reduces flow when the room reaches the set level. Manual valves don’t sense temperature — you set them and the radiator stays roughly at that level until you change it. TRVs are usually better for comfort and efficiency in rooms you don’t want overheated.

How do I choose the right radiator valves for my radiator and pipework?

Start by checking your pipework direction: you’ll need angled valves for pipes coming from the wall and straight valves for pipes coming up from the floor. Then match the valve thread size to the radiator (most modern radiators use standard sizes, but it’s worth confirming). Finally, choose the style and finish to suit the room — traditional, modern, or colour-matched — and consider TRVs if you want better temperature control.

Radiator Valves Archives

Buying Radiator Valves: Quick Tip

Before you pick a finish, make sure you’ve got the right valve shape for your pipework: straight for pipes coming up from the floor, angled for pipes from the wall. If you want better comfort and to stop rooms overheating, go for TRVs on the inlet side, then use a matching lockshield on the return for balancing. Once the type is right, choose the style and finish to match your radiator.

Who Should Buy Radiator Valves?

And who should consider alternatives

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Who Should Buy

Anyone fitting a new radiator/towel rail or replacing old valves

Ideal if you’re swapping radiators or your current valves are stiff, leaking, or outdated. New valves can improve control and appearance.

Homes wanting better temperature control room by room

Great if some rooms overheat while others feel cold. TRVs help regulate individual rooms without constantly adjusting the boiler.

People who care about matching finishes and a tidy install

Perfect if you’ve chosen a specific radiator finish (black, anthracite, brass, chrome) and want the valves to look intentional, not like an afterthought.

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Who Shouldn't Buy

You need an immediate fix for a bigger heating problem

If radiators aren’t heating due to sludge, air, pump issues or boiler faults, new valves won’t solve it on their own — the system needs diagnosing first.

Your system has specific restrictions on TRVs

Some setups require at least one radiator without a TRV (often where the room thermostat is), and certain older systems have limitations. If in doubt, check what your system needs.

You can’t safely work with drained pipework or heating circuits

Valve replacement usually involves draining or isolating parts of the system. If you’re not confident, it’s better handled by a qualified plumber.

FAQs About Radiator Valves

Help with types, compatibility and choosing

What do radiator valves do?
Radiator valves control the flow of hot water into and out of a radiator, which affects how warm it gets. Most radiators use two valves: one to control or regulate heat on the inlet side, and another on the return side that helps balance the system so multiple radiators heat evenly.
What’s the difference between TRVs and manual radiator valves?
A TRV (thermostatic radiator valve) has a sensor that reacts to the room temperature and automatically reduces flow when the room reaches the set level. Manual valves don’t sense temperature — you set them and the radiator stays roughly at that level until you change it. TRVs are usually better for comfort and efficiency in rooms you don’t want overheated.
How do I choose the right radiator valves for my radiator and pipework?
Start by checking your pipework direction: you’ll need angled valves for pipes coming from the wall and straight valves for pipes coming up from the floor. Then match the valve thread size to the radiator (most modern radiators use standard sizes, but it’s worth confirming). Finally, choose the style and finish to suit the room — traditional, modern, or colour-matched — and consider TRVs if you want better temperature control.