Thermostatic Radiators Valves – What Are They, Types & Which Are the Best?

radiator installed in kitchen

Maintaining a comfortable temperature in every room in our home is a must during frigid winter days. Comfort is achievable with the help of a Thermostatic Radiators Valve (TRV). If you are buying an energy efficient boiler to keep running costs down due to gas price rises, then TRV’s can help even more.

hive thermostatic radiator valve

Thermostatic radiator valves are self-regulating valves used for adjusting hot water based on the room’s temperature. A TRV is fitted to the water heating system to control a room’s temperature by modulating the hot water flow.

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TRV is just one of the many heating controls in your home and is also one of the most energy-efficient. According to a 2018 test report by Salford University, a heating system consumes around 42% less gas when fitted with a TRV. 

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Types of heating control

A central heating system is the upgrade of an ancient furnace to provide warmth to any building’s interior. Your boiler & central heating has different controls for managing the heat it provides to a room. if you’re considering getting the best radiators to keep costs down, then you need to ensure that you can control them efficiently too.

Manual room thermostat

These are the thermostats you most commonly find in hallways which tell your boiler when to turn on and off. A manual room thermostat is a simple and inexpensive system that allows users to manually crank the heating system to a comfortable temperature. 

Programmable room thermostat

This thermostat has a built-in timer that schedules the boiler to automatically go on or off. The heating system activates at different times of the day as it is programmed. 

Thermostatic radiators valves

These are the valves attached to the radiator that controls the temperature in individual rooms. Using an app or smart speaker, TRVs can work manually or through smart settings. 

Smart heating controls

Known best as smart thermostats, these are innovative heating controls that work through the internet. Users can manage, adjust, or schedule their hot water settings on their boiler remotely using an app.

TRV is the most popular heating modulator because it is convenient to use and energy-efficient. If you know how to correctly set up the TRV on the regulator, you may be able to maximize your boiler’s function. 

The Building Regulations in England and Wales address this significant step in addressing energy efficiency in every home. Starting in June 2022, it requires installing TRV in all heated rooms in a boiler replacement. In the past, it was only a recommended “good practice,” but this new regulation may benefit many households from spiralling energy consumption. 

What are thermostatic radiators valves?

The thermostatic radiator valve is often used with a room thermostat for setting the heating in the home just right. It looks like a simple valve with dials attached to the side of the radiator but works rather ingeniously on the inside.

TRV contains a plug and valve that reacts to its surrounding temperature by expanding and contracting. Its valve head sits on top of the body and adjusts a pin in the valve body, causing it to open and close.

As the room heats, the valve head expands and blocks the valve body, receiving less hot water into the radiator.

When the room is cool, the valve head contracts and opens the valve body to receive more hot water into the radiator.

white radiator in an apartment

Thermostatic valves design

The classic TRV is made of wax. However, it now comes in an innovative liquid model. Both of these designs offer automatic adjustments but with a little difference.

Wax TRV refers to the wax plug forming a wax motor that expands in volume when exposed to high temperatures. This causes the valve to expand and contract in its surrounding temperature.

Liquid TRV has a clear liquid capsule that functions with the same contraction and expansion as the wax model. 

The difference between these models is the response time of the element to temperature changes. Liquid TRV reacts quicker than wax, providing quicker adjustment in changing the water flow. Although, of course, they tend to be pricier than wax. 

Overall, many fitters still consider using wax because of its flexibility for various designs. Unlike the liquid model, wax can deliver a superior surface area to volume ratio. It is also non-flammable without the solvent that liquid TRV does, which is a high consideration for home safety.

What are the benefits of thermostatic radiators valves?

The ambient room temperature in the home varies according to its uses, population, or exposure to a heat source. For example, your living room receives the most traffic than the bedroom. Likewise, rooms facing the window with access to sunlight may have a different temperature than those that don’t. 

Installing a TRV provides flexibility and efficiency in handling these varying room temperatures while minimizing energy wastage and are a great way to keep energy bills down.

In busier and heated rooms, you can set the TRV lower to give it just the right temperature without the risk of overheating. 

You can set it even lower in less populated, cooler areas or spare rooms. It will avoid heating the rooms that are not used, cutting your energy consumption to a huge margin. 

Using thermostatic radiators valves with thermostats

A room thermostat has long provided users with comfort in extremely cold weather. But, there is more to a thermostat when fitted with trusty thermostatic radiators valves. 

A room thermostat works by measuring the temperature in a room and then sending a signal to the boiler. The boiler will run until the needed temperature is reached. All rooms where the radiator valves heat all at the same time. 

The thermostatic radiators valves complement and maximize the task of the thermostat by working on a specific radiator. 

While it is recommended to fit TRV in every radiator, installing it in a room with a fixed thermostat is unnecessary.

When installed in the same room, the two heating controllers will interfere with each other’s control. The scenario is that when the TRV is set below the room thermostat temperature, the TRV will shut off the radiator. The central heating boiler will continue to run to reach the thermostat’s set temperature.

When the two are set at a similar temperature, they will compete over control and may turn off the heating system.

Smart TRV

Technological advancement did not leave behind the TRV with the development of smart TRVs. These are electronically controlled devices for providing individual and room-by-room temperature settings. You can control smart TRVs best with a smart thermostat.

Smart TRVs use the same mechanism to track the room temperature and pass hot water into the radiator. You can now operate them through an app or hub using voice control and automation. Opening and closing the valve to the appropriate room temperature is convenient. 

Upgrading your standard TRV to a smart TRV is a personal choice. Its benefit is mostly in remotely controlling the valves and turning your energy-efficient boiler into a smart boiler.

man adjusting radiator valves

With the conventional TRV, your choices are the 1-5 settings. With smart TRV, you can automatically direct the valve to open or close at a specific hour. And you can conveniently do this wherever you are at the moment. 

However, one of the drawbacks of smart TRV is that most units run through a battery. You may need to change it periodically, or it will diminish to function like the standard TRV. 

The good and the bad of thermostatic radiator valves

Like most devices, TRVs also have benefits and some drawbacks that come along with them. 

Benefits of TRV

One of the main reasons for regulating TRV in the heating system is its energy efficiency. It can reduce gas consumption and significantly lessen the impact on the environment. 

By smartly controlling the temperature room-by-room, it avoids energy wastage. It also makes the room more comfortable and compensates for the necessary heat. 

The correct room temperature also minimizes the risk of frost damage and mould. These are the potential climate-based issues that mostly hasten the depreciation of the building. 

Downsides of TRV

Maintenance of TRV is unlikely when it is installed properly. But it does not render it free of product issues.

Over time, the product will depreciate, and older units could be at risk of malfunctions. Most commonly, the device can become unreliable and may not be able to gauge the correct temperature. It may switch off the heating system or cause serious overheating.

The best way to avoid this is by periodically checking the TRV to ensure it detects the accurate ambient heat. You should also avoid setting it at a high temperature for a long time. 

The drawback of thermostatic valve settings

Another disadvantage of the thermostatic valve is the graduation of its settings. Conventional TRVs provides inexact temperature using numbers instead of degree Celsius. It may need some trial and error to get the level of warmth that users need.

The values of the TRV may vary according to their make. The numbers 1-5 translate to the temperature at which it would come on:

  1. Under 10 to 15⁰C
  2. At 15 to 17⁰C
  3. At 18 to 20⁰C
  4. At 21 to 22⁰C
  5. Max level where the valve is always open

The best thermostatic radiator valves 

Here are some of the best TRVs trusted by many heating engineers and plumbers that you can get for your home:

Drayton TRV 4

Drayton TRV4 is one of the top-of-the-line TRV products rated for its efficiency. It has various designs, such as the White, Classic, Chrome, and Anthracite TRV. It features a sensitivity of about 0.22mm/⁰C and a response time of 20 minutes. 

The settings for Drayton are numbered 1-5 and max with a setting range between 10 to 30⁰C. It has a contemporary slim design with non-stick interiors. Drayton’s accurate liquid sensor is standard for the TRV system. 

Drayton has a 15mm straight angle for universal fit to the standard UK valve size. It offers reverse or bi-directional flow that you can fit either on the flow or the return pipe. 

Honeywell VT200E

Honeywell is a top player of the classic TRV gauging its performance, reliability, and quality. The VT200E is ideal for connection sizes of 10mm with a bi-directional flow design. You can fit the device vertically or horizontally, whichever is necessary to achieve optimum temperature control performance. 

To minimize alterations on the pipework during installation, the VT200E has an adjustable tailpiece. It also comes with a push fit fitting.  

Like most TRVs, Honeywell provides frost protection to protect your home from freezing when you are away from home. It also has a decorator’s cap instead of the usual chromed head to protect it from paint splashes when re-decorating. 

Hive smart radiator

Hive Smart Radiator is one of the best smart thermostatic valves, especially when used with the Hive Smart Thermostat. This intelligent system allows for automatic temperature adjustment and other remote settings.

When using the Hive app, users can schedule when the device will turn on or off on demand. They can also set the temperature from the app or directly in the radiator valve. 

Hive operates through Alkaline batteries and an internet connection of at least 1.5Mbps. It will work with the current Hive Hub or Hub 360 but not with the Hive Hub 1. 

MYSON TRV 2-WAY

The Myson TRV 2-way is the most complete radiator valve range for most central heating systems. It has unique two-way engineering or bi-direction and boasts Myson’s patented bonding technique. The valve functions well and without trouble regardless of which way the water flow.

The product has greater flexibility with size ranges of 8mm, 10mm, and 15mm. One of its best features is the positive shut-off technology that prevents water leakage if the radiator is removed. 

Myson TRV is A-graded with its high reliability and suitability for all radiators and towel warmers. 

FAQ’s

What is the common issue with TRV?

A sticking valve problem is prevalent with TRVs. It often happens when turning it on for the first time at the change of the season. It may need a little grease work (quite literally) with some WD40 to keep it moving smoothly.

Are radiator valves of universal fit?

Every home’s pipework is different. Thus, radiator valves also have different sizes. When finding the right TRV for your boiler, consider the pipe size, angle, or direction. TRVs also have different finishes and designs to suit your taste for decoration.

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