Best Thermostatic Radiator Valves Buying Guide
Also known as a TRV, thermostatic radiator valves enable you to more accurately control the individual temperature of a radiator by measuring the temperature of a room and adapting its heat output. This means you can adjust the temperature of a radiator to match its room, rather than having the same heat output throughout the house, improving efficiency and so potentially saving you on your energy bills.
One your room reaches the desired temperature level, the TVR will close its valve to stop water flowing into the radiator and preventing it from getting hotter. It also means you can heat rooms individually and so have a lower temperature in a room you do not use as often as the main rooms in your home. This enables you to create different heating zones in your home, all fed by the same centralised boiler.
Thermostatic radiator valves are available in two main designs – wax or liquid. The TVR has a capsule that sits in its external head which is filled with either wax or liquid. The contents of the capsule expand as the room warms up, eventually pushing a pin in the valve to stop hot water coming into the radiator when the room temperature is above the desired temperature. As the room cools down, the capsule contracts until the pin moves back, letting the hot water flow return into the radiator.
TRVs with liquid are more responsive to fluctuations in temperature than wax, which can take a little longer to expand and contract, meaning liquid thermostatic radiator valves can be a little more expensive.
A lockshield valve is one of the valves on your radiators. It is usually covered with a plastic cap. The word lockshield is a reference to this cap. It means that once a valve has been adjusted, the cap is secured over it to stop the valve being accidentally knocked or altered.
The cap to a lockshield valve can usually be removed by either pulling it or unscrewing it. On some models, the cap is screwed on and you will need a screwdriver to unscrew it.
Once the cap has been removed, the valve looks a little like the end of a spindle. This spindle can be either square or half-moon shape. It can usually be adjusted by hand but if the radiator is older, you might find you need an adjustable spanner to move it.
A lockshield valve can be used to adjust how quickly a radiator takes to warm up. By opening the valve, more hot water can flow through the radiator meaning it will warm up faster. By closing the valve, the flow of hot water is reduced and the radiator will not warm up as fast.
Most people don’t even know what a lockshield valve is, never mind how to use one. But they are actually a really useful feature on a radiator to allow you to adjust how quickly an individual radiator warms up.
There are currently two main types of radiator valve widely available, the manual (either lockshield or wheelhead) and the thermostatic valves. And there are clear differences between the two:
What are manual radiator valves?
Manual radiators are simple devices which need to be opened and closed by hand. You will usually find a pair of manual radiators on your radiator, a wheelhead and a lockshield fitted at opposite ends. A wheelhead valve has a plastic cap which turns its inner valve, while a lockshield is set in position and requires you to remove its plastic cap to manually turn the valve to open or close it. The wheelhead is either set open or closed while the lockshield can be adjusted to balance the flow of water into the radiator.
Manual radiator valves are simple devices which are straightforward to use, but you have you remember to return the valve to its original position after adjusting or it will stay where you have set it, potentially using more energy than you intended.
What are thermostatic radiator valves?
Thermostatic Radiator Valves – or TVRs – mean you have greater control over the temperature in your home as they can be set to the temperature you want an individual room to be. The TVR then adjusts the flow of hot water into an individual radiator once the room gets to the temperature you want and will then kick back in with heating once the room temperature dips too low. This means your radiator is managing the heating of an individual room and you can have rooms at different set temperatures, even if they all run off the same central boiler.
However, TVRs are not recommended for rooms where you already have a thermostat installed, as they will 'compete' with each other to control the room temperature. And thermostatic radiator valves are not suitable for bathrooms or shower rooms, as excessive heat caused by water steam can cause the valve to shut down.
As well as ensuring you have the right size of TVR to fit your pipework, there are other things to look out for:
Wax or liquid - today's thermostatic radiator valves can use either wax or liquid in its temperature-sensitive capsule head. Wax TVRs are typically cheaper but are a little slower to work, whereas liquid responds quickly to fluctuating temperatures but are usually the most expensive.
Straight or angled - as with manual valves, thermostatic radiator valves also come in a choice of positions, so you can opt for straight valves, angled valves or H-block as well as corner valves, depending on your pipework.
Pipe connection – make sure the TVR you are choosing will fit with the diameter size of your radiator’s pipework. 15mm is a standard pipe size but it can be as small as 8mm or as larger as 20mm. Know your pipe size before buying a thermostatic radiator valve.
Valve position – most thermostatic radiator valves fit to the bottom of the radiator, but you can also choose to fix it to the side or top. To do this you will need to ensure the TVR is bi-directional as the top pipe is most likely to be a return pipe, and not an inlet pipe.
Colour – today’s thermostatic radiator valves come in a choice of designs so you can find a good match for both your radiator and room style. Colours available include chrome and white and you can even get treated wood tops for a period home look.
Smart TVRs – some TVR models are now smart enabled so you can control them remotely via your smartphone or device.
Convenient to use, and with no need to replace the whole valve, our top pick - the Myson Standard Thermostatic Radiator Valve Head - is a cost-effective way to ensure your TVRs continue to work as they should. A standard-sized head replacement for the Myson TVR 2-Way, it is a handy piece of radiator kit to have, should your existing TVR cap fall foul of everyday wear and tear and can save you replacing the whole valve unit.