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Radiator Valves Explained

It is usually a good idea to install new radiators so that your heating system works better. But the important part is that the efficiency of the radiator depends upon the valves you choose.

To make things easier for you, companies don’t include valves when you buy the radiator. Given that every home has its unique lifestyle, the choice for the valve is left upon you. This also means that you have to make the right decision for the type, size, and style of the valve you choose for you!

You don’t have to worry about a thing since this article has got you covered. We will provide you with everything you need to know to buy the best valve that suits your conditions.

What is the Function of a Radiator Valve?

Every radiator needs a pair of valves, each with its function. The valves act like taps through which you can control the amount of heat they emit.

  • The amount of hot water going into the radiator is controlled by one valve.
  • The second valve controls the amount of heat emitted by the radiator (lockshield valve)

Balancing your radiators

The amount of water entering, staying in the radiator, flowing out of it, and going back to the pipework is controlled by a lockshield valve. It is fixed in its position, so you cannot move it. The professionals set it up to ensure that water is uniformly distributed throughout the property.

The Different Types of Radiator Valves

Radiator valves are divided into two main types; manual and thermostatic. Due to the advancements in technology, smart radiator valves are becoming more and more of a hit!

Manual radiator valves

You can set this radiator valve up according to your choice of temperature in the room. You can adjust the water flow and heat coming out of the radiator through manual valves.

Manual valves are the easiest to use and have a smaller size compared to thermostatic valves. You need to be careful about keeping an eye on them once you have turned them on. Otherwise, it can result in the wastage of precious resources.

Thermostatic radiator valves (trvs)

TRVs or thermostatic radiator valves are more advanced in their functions, offering greater control over the temperature you wish to set.

This is how a TRV works. To sense the temperature, TRV has a liquid or wax. Once your room has reached the desired temperature, TRV will automatically stop the water flow, which will eventually prevent the radiator’s temperature from rising. In a word, TRVs would make your radiator self-managing saving your money you would spend on unneeded heating otherwise.

Smart radiator valves

If you are looking forward to having a smart thermostat installed in your home, you might want to consider smart radiator valves. Tado, Honeywell, Netatmo, and various other manufacturers produce these radiator valves.

You must be wondering how does the smart thermostat work. It is connected to Wi-Fi by which you can get to control your heating through an app.

The numbers on radiator valves – what do they represent?

Radiator valves have numbers representing the amount of heat emitted by the radiator on a scale of 1-6. Usually, turning the valve to the number 2 corresponds to approx. 16°C, 3 to approx. 20°C (room temperature), and 4 to around 24°C.

Why do manufactureres use numbered system rather than the exact temperatures?

The question pops up in our minds: Why is there a numbered system rather than the exact temperatures. The answer is that manufacturers cannot guarantee the temperature in the room. This is because the temperature of the room also depends upon the following factors;

  • Home insulation.
  • Radiator location.
  • The performance of the boiler.

Why are radiator valve settings important?

You might not be wanting a uniform temperature throughout the home. Some of you might prefer a warm bathroom but a cool bedroom. Also, there is no need to heat the rooms that are barely in use. Keeping a check on radiator valve settings will help you save energy and money.

Tip: Below 20°C, you can save up to 6% in energy use by lowering the temperature by each degree.

A Few Things to Consider Prior to TRVs Installation

  • Don’t install it with the thermostat: If your room has a wall-mounted thermostat, you better not install TRVs with it since both will compete to control the temperature of the room.
  • It is not recommended to install TRVs in bathrooms or shower rooms: The heat produced from the warm water will shut the radiator off since it will take it as an increase in the temperature of the room. Though, the radiator is supposed to remain on to lower the condensation.
  • Ensure a yearly check on TRVs: Although they are self-regulating, it is recommended to get them checked annually to ensure they are working fine.
  • Check that your heating system is balanced: You need to ensure the equal distribution of the flow of hot water throughout your property. This will enable the TRVs to work at their best. Also, the radiators will heat up at a similar rate.

Angled, straight, h-block or corner valves – what are they?

  • Angled Radiator Valves have a bend of 90° enabling the radiator to connect with the pipework at an ‘angle.’ Angled radiator valves form the most common type in the United Kingdom.
  • Straight Radiator Valves, as the name suggests, are devoid of any bends and enable the straight flow of water.
  • H-block Radiator Valves are not for BOE (Bottom Opposite End). They are for middle connections. They are simpler to install, replace, and save up some space for you as you won’t have to install the radiator on both sides.
  • Corner Radiator Valves are recommended for homes that have limited space. They are similar in structure to angled valves except that they do not come from beneath the radiator. Corner radiator valves are complicated to adjust since they are installed facing inwards and parallel to the wall.

Straight, angled, corner, or h-block valves – what is compatible for you?

You need to choose the radiator valves keeping in mind the positions and locations of your radiator inlets such that they smoothly connect with the hot water pipes.

Ask a professional

It must be a straightforward process to find inlets for the radiators and pipes. Still, if you are unsure, we would recommend you to consult a professional. We are an enquiry away!

When do you need angled valves?

A significant number of radiators in the UK have BOE connections. This means that these connections protrude out from the radiators from either side at the bottom horizontally. Since the pipework pops out of the wall, angled valves are used to connect the radiator with the pipework.

When do you need straight valves?

Some of the latest radiators have middle connection valves (in the bottom centre). They can save you a lot of space since there is no pipework protruding out of the sides. If the pipework is popping out from the flooring and the radiators have inlets at the back instead of sides, you must use straight valves to connect them.

What is the right radiator valve size for you?

Before getting to the actual question, it is vital to know what we mean by the radiator valve size. By the radiator valve size, we don’t mean the valve’s actual size here; rather, it corresponds to the connection and pipework’s size.

Mostly, you would come across 15mm pipes, and the valves usually fit this size. However, pipework between 8mm to 28mm also exist.

If your pipework is not of the average size, I.e., 15mm, and you are trying to get the right valves, adapters can solve the problem.

Different styles of radiator valves

Always remember that the style of the radiator valves comes at the last. The right type and the adequate size should be your priorities while choosing valves.

There is a broad array of styles you can choose from;

  • Minimalist
  • Simple
  • Traditional
  • Contemporary
  • Classic
  • Elegant

Radiator valves and their costs?

Radiator Valves Estimated Costs
Manual Radiator Valve £5 – £35
Thermostatic Radiator Valve £5 – £120


Smart Radiator Valve £50 – £200 (Cost of Smart Thermostat Excluded)



Now comes the cost of installation. A professional heating engineer, on average, would cost you around £100 – £350. It is better to get multiple quotes and choose the most viable one.

Ways to get the right radiator valves!

The type and size of the radiator valve you buy would depend upon the pipework and radiators at your home. However, the style of radiator valves is upon what you like. Contacting a professional heating engineer is a fine choice to ensure quality work. Get free quotes from professionals while sitting at your home just by sending us a quick enquiry!