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A guide to radiator valves


The valves on an everyday radiator or towel rail are essential in order to maintain the control of water flow through its pipes, as well as to ensure your radiators heat up effectively, and to provide you with a comfortable and warm living environment. With a large variety of radiators currently available on the market in varying shapes, styles and sizes, not every valve is universally suitable to all radiators.

In this article, we will give you a run through of how they work, the different types as well as the benefits of each.

Choosing the right radiator valve for you

One of the easiest mistakes when purchasing and getting around to installing a radiator is overlooking the need for valves. Purchasing the correct valve is essential to ensure your new radiator works as it should. There are currently three main types of valves, which all function differently and come in straight and angled designs:

Manual radiator valves

You will typically find manual valves to be the more common type of radiator valve due to their “on and off” nature, allowing you to simply twist the valve to allow water to flow through it, or twisting it again to turn it off. It’s important to note that whilst manual valves are easy to use, there is no way to monitor the amount of water, and ultimately energy, being used, which typically means an increase in your heating bill.

Thermostatic radiator valves

Compared to manual valves, thermostatic radiator valves (TRVs) give you a more intelligent method to control temperature when turning the dial. They allow you to have control of the energy being used by each individual radiator, which will save money on your energy bills in the long term. These valves actually open and close internally depending on whether the surrounding air temperature has reached the desired level, regulating water flow and using only as much as is actually needed. It’s important to note that it’s not advised to install any TRVs in the same room as a room thermostat. The TRVs will shut off when the radiator reaches a set temperature, but the boiler will continue to turn on and off, not knowing whether the valves have reached their set temperature.

Lockshield valves

Last of all, lockshield valves are used to control the amount of water that flows back out of the radiator and through the return pipework. You will normally find these valves covered by a plastic cap. They are also there to ‘balance’ your radiator, which ensures that your radiators heat up efficiently and at the same rate, with the water in the system being distributed evenly.

Angled or straight valves?

Another important question is whether you need angled or straight valves. To answer this, it depends on your existing pipework and where the inlets currently live on your new radiator. If you have bottom inlets and your pipes currently come up from the floor, you will need straight valves. If your pipework comes from the wall, you will need an angled valve instead. You are likely to come across the terms H-block and corner valves when searching around for valves. Corner valves tend to be a space-saving solution to fit snugly in tighter spaces whereas an H-block valve gives you the ability to hide your radiator’s pipework and fits universally on towel rails as well as centrally-connected radiators.

The table below provides some further detail on the type of valve you will need depending on your pipework and inlets:

 Through Wall (Pipework)Through Floor (Pipework)
Bottom inletsAngled radiator valveStraight radiator valve
Side inletsAngled radiator valveAngled radiator valve
Middle inletsH-Block valveH-Block valve

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The world of TRVs

TRVs can be pointless if they’re not used correctly, and should never be fitted in the same room as a wall mounted thermostats due to a clash in temperature management. Due to new developments in valve technology, we now have modern innovations coming into play with eTRV (also known as smart TRV units). For example, you can programme eTRVs to ensure the room is fully heated and at the right temperature at a specified time of day.

You can now also buy fully-fledged kits which will work in multiple zones and operate with multiple wireless TRVs, communicating with a main controller and responding to commands to the boiler. Creating zones with each radiator means you can control which radiator is to be turned on or off as well as keeping track of temperatures and the need for these radiators. Devices such as the Nest Thermostat give you the ability to control your existing radiator valves without having to opt for new devices. Honeywell stands out in the smart TRV market, especially with their Evohome Multi Zone kit, which can be controlled using their very own controller as well as a third party thermostat such as the Nest.

Smart TRVs, in contrast to regular TRVs, have much closer control with regards to temperature, giving you proper temperature values instead of a scale between 1 and 5. This of course means less heat being wasted, which leads to an effective and exciting way to save on your energy costs and have full control of your heating. According to the Energy Saving Trust, you could save between £70 and £150 per year using TRVs to lower the heating in rooms you’re not using. There is a huge convenience factor to parting ways with regular TRVs, as smart TRVs take the element of manual changes to the valve out of the equation and give you more flexibility with the added electronic element.

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