Types of radiator valves: A professional’s guide

Radiator valves are essential components of a central heating system because they allow you to control and optimise the heat output in different rooms by regulating the flow of hot water into the radiators within your property.  The results? Increased comfort, energy efficiency, and cost savings. Utilising radiator valves effectively can lead to a more balanced, comfortable, and environmentally responsible heating system in your home.

However, there are different types of radiator valves to choose from and your choice will be influenced by factors such as the compatibility of your heating system, room usage, zoning requirements, preferences, energy efficiency goals, and budget. We delve further into the importance of radiator valves within a central heating set up, followed by a detailed look into the types of radiator valves on the market.

Why are radiator valves important?

Radiator valves are important for:

Temperature control

Radiator valves allow you to control the temperature in individual rooms or areas of your home. By adjusting the valve, you can increase or decrease the flow of hot water into the radiator, which directly affects the amount of heat radiated into the room. This level of control ensures that you can maintain a comfortable temperature in each space, optimising comfort and energy efficiency.


Different rooms in a home have varying heating requirements based on factors like room size, insulation, and occupancy. Radiator valves enable you to create heating zones by adjusting the heat output in each room. This prevents over-heating in rooms that require less warmth and ensures that rooms with higher heat demands are adequately heated

Energy efficiency

Radiator valves contribute to energy efficiency by allowing you to tailor your heating to specific needs. For example, if a room is unoccupied or receives ample sunlight, you can reduce the heat output by partially closing the valve. This conserves energy and lowers utility bills.

Comfort and customisation

Being able to fine-tune the temperature in different rooms enhances your overall comfort in your living space. Each occupant can adjust the heat according to their preference, creating a more pleasant environment.

Preventing overheating

Radiator valves, especially thermostatic ones, help prevent overheating in rooms. When the desired temperature is reached, the valve will begin to close, reducing the flow of hot water. This prevents the room from becoming excessively hot and maintains a consistent and comfortable temperature.

Balancing the system

In multi-radiator heating systems, radiator valves assist in balancing the distribution of hot water. By adjusting the valves in different radiators, you can ensure that heat is evenly distributed throughout your home. This prevents situations where one room is much hotter than another.


Advanced radiator valves, such as programmable and smart valves, offer automation features that enable you to schedule heating periods. This ensures that rooms are comfortably heated when needed, reducing energy waste.

Types of radiator valves

There are several types of radiator valves available, each with its own features and benefits.
The most common types that we work with in properties across London and the surrounding areas are manual and thermostatic valves:

Manual radiator valves

Manual valves are some of the most common radiator valves in the UK as they are simple and easy to use. A manual valve works in a similar way to a tap, whereby you turn it anti-clockwise to turn it on and clockwise to turn it down or off. It will keep the radiator at a constant temperature regardless of the temperature of the room.

Despite being easy to use, they tend to be less energy efficient. This is because manual valves rely on you being quick to react to sudden temperature changes – even though this isn’t always possible or practical. The slower you are to react and make changes to the temperature, the more heat you will use unnecessarily. For this reason, manual radiator valves are ideally suited for use in rooms which are fitted with a room thermostat.

Thermostatic radiator valves

Thermostatic radiator valves (TRVs) have become increasingly popular over the years, particularly of late, for their ability to help reduce energy consumption and save money on heating bills. TRVs have a built-in temperature-sensing element that automatically adjusts the valve’s opening based on the room temperature. Unlike manual valves, TRVs are fully automated, making them capable of maintaining a consistent temperature in a room by modulating the flow of hot water. In turn, this makes them much more energy efficient when compared to a manual valve. They usually have a numbered dial with temperature settings to allow you to choose the desired level of warmth.

Thermostatic valves are in full control of temperature regulation 24 hours a day. They mean your home can be kept at a steady temperature even when you are out for the day or sleeping. However, a TRV is not ideal for use in rooms which also have a room thermostat as this can affect the temperature readings.

Can a manual radiator valve be replaced with a TRV?

As professional heating and plumbing engineers, homeowners often ask us whether it is possible to upgrade manual radiator valves to thermostatic ones to provide more control over the temperature of the radiators. The simple answer is yes, we can upgrade manual valves to TRVs. Plus, by replacing your manual valves with thermostatic valves, you could even help your energy bills decrease. In fact, according to TheGreenAge.com having thermostatic valves installed in every room could save you up to 40% on your energy consumption.

We always recommend enlisting the help of a professional heating engineer to change a radiator valve. It can be a long and tricky job which is better suited to a trained professional who knows their way around a heating system.

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Lockshield valves

Lockshield valves are used in conjunction with manual or thermostatic valves and are all about achieving balance across your heating system. They are usually located on the opposite side of the radiator from the control valve and are designed to be adjusted with a special wrench. Lockshield valves are used to balance the flow of hot water between radiators in a multi-radiator system, ensuring that each radiator receives an equal amount of heat.

Lockshield valves are small, and easy to overlook but, they are one of the most important features of your heating system and EVERY radiator needs one! Without this valve (which you can see in the image below), the radiators in any room furthest away from the boiler (such as a bedroom) will never get warm.

Smart radiator valves

Smart valves are one of the newest developments in home heating technology and offer complete and flexible control over your heating. You can set them to come on and off when you want, as well as using them to adjust the rad temperatures as and when too.

Smart valves combine the features of programmable TRVs with remote control capabilities. They often integrate with smart home systems and can be controlled by voice commands or automated routines. For example, you might have a smart valve routine that detects when you’re coming home and then carries out a range of actions. This could include opening smart radiator valves as required. Some models also offer energy usage insights and optimisation features.

What is the difference between a smart thermostat and a smart radiator valve?

Whilst they are both components of a smart heating system, smart thermostats and smart radiators serve slightly different purposes and functions within the system.

A smart thermostat

This is a central control unit that manages your heating system from a central location. It uses built-in temperature sensors to gauge the overall temperature of your home. This enables you to set heating schedules and temperature presets for different times of the day. Smart thermostats can be controlled remotely through smartphone apps and offer insights into energy usage.

A smart radiator valve

This is attached to individual radiators and focuses on room-level control. It measures the temperature in the room and adjusts the heat output of that specific radiator. This allows you to create heating zones, tailoring temperatures to different areas. Smart radiator valves can also be scheduled individually and controlled remotely through apps. They contribute to energy efficiency by preventing overheating in unused rooms.

In essence, smart thermostats manage your entire heating system centrally, while smart radiator valves provide localised control by adjusting each radiator’s heat output. Using both devices together can create a highly customisable and energy-efficient heating solution for your home.

Straight or angled radiator valves

When thinking about radiator valves, shape matters. While the primary purpose of radiator valves is to control the flow of hot water into radiators, the valve shape can influence factors such as installation, ease of use, compatibility, and overall visual appeal. For each type of radiator valve there are different valve shapes that enable the radiator to be connected to the pipes.

The most influential factor of valve shape will be where your central heating pipes are coming from. For example, when you look the pipes connecting to your radiator, do they come up from the floor or out from the wall? For pipework that comes from the floor (and the radiator has inlets at the bottom), you will probably choose straight valves. For pipework that comes from the wall (and the radiator inlets at the sides), you will likely need angled valves. However, this will be different for every home and scenario.

The engineers at Happy Dog Plumbing have a wealth of knowledge with all aspects of heating. So, if you are thinking of upgrading to TRVs in the coming months in order to help minimise energy costs, or you have another heating problem that needs a professional touch, you know who to call.

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Get in touch

We’re available to call on 0208 8797372 or email hello@happydogplumbing.london. We’re always happy to consult on what your Wandsworth property needs!