Radiator Valves Explained: Types, Functions, Working, Buying Guide

In this blog post, you’ll read:Radiator valves may look complicated. But when you get to it, they are very simple and worthy. In this guide, you'll go through its types, components, working method, and other important terms. Please don't skip any part and learn everything about it.
Table of Contents

So, you’ve settled on a radiator but didn’t figure out valves for it, right? Radiator valves may look complicated. But when you get to it, they are very simple and worthy. In this guide, you’ll go through its types, components, working method, and other important terms. Please don’t skip any part and learn everything about it.

What is a Radiator Valve?

radiator valve is a self-regulative valve attached to the radiator to control the temperature of a room. To clarify, it’s a valve fitted with the radiator and controls hot water flow for the radiator to change the temperature of the room. It’s also known as Thermostatic Radiator Valve (TRV).

From How2D2


Generally, there are two types of radiator valves availableManual and Thermostatic. However, some companies manufacture a different kind of it… that is an intelligent radiator valve. 


This is the most commonly used type of radiator valve. You can open, close, or partially open it to control your room’s temperature. Also, it is helpful for constant heating. For example, if you need idle heat for your room, this valve can help you. 

But the downside is, that this type of valve is not automated. They will heat all your rooms all day and night, but it’s not necessary. So, you’ve to control it manually whenever you want to change the temperature.


Thermostatic Radiator Valves (TRV) come to remove the drawbacks of the manual types. This is an automated valve, so you don’t have to control it by yourself. In addition, you can set the radiator to a certain level… and when it touches that point, this valve will shut off to stop further water flow into the radiator. However, TRVs are way more efficient than manual ones.

thermostatic valve works
thermostatic valve works

Made of

A radiator valve is a combination of two different parts. These are the plastic part’s upper side (thermostatic unit), and the other is the metal part or valve body. 

The upper cap or shelter is the ‘thermostatic head’; other parts are installed inside it. A ‘thermal element’ or ‘sensor’ is also installed to sense the temperature of the water. Besides, a ‘heat resistant molding’ is present there. 

You may see some numbers or symbols on this unit. These numbers are representing how much heat the radiator is delivering right now. It has a level between 1-5/6 (vary on models). You can follow the box that came with that valve to know which level produces how much heat.

Now come to the valve body. On the up, there is a ‘thermostat removal nut.’ This nut joins the valve head and body together. If you undo this nut, the head will disassemble from the valve, and you’ll see a ‘pin.’ The valve probably has two inlets, one for the heat source and the other for the radiator

There’s a ‘connecting nut’ that connects the pipe and valve on the heat source inlet. Similarly, on the radiator inlet, there’s a ‘radiator securing nut’… that ensures the bond between the valve and the radiator.

Trv Heater
Trv Heater

How does a Radiator Valve Work

All a radiator valve controls the hot water supply into the radiator to keep the balancing temperature in your room. However, it looks small… but it’s a mighty device that controls everything on your radiators.

As you know, radiator valves have two inlets. One inlet connects the valve with your heat source or boiler, and the other links with the radiator. Hot water comes to the valve from the heat source through the copper pipe or plastic pipe. After that, hot water enters the radiator.

The radiator valve senses the temperature through the thermostatic element. When the hot water comes and tries to enter the valve… the valve measures the room’s temperature… if it’s hot out there in the room, the valve head pushes the pin down and shuts off the valve until the cold temperature is down

On the other hand, it lets the hot water in if it’s cold and needs heat. After that, when the room reaches the desired temperature, TRV will again close the hot water supply.

Some people get confused over the indicator number on the radiator valve. Frankly saying, most radiator valves are set to 20oc when the number is set to 3. For each number, there is a 4/5oc difference (depending on valve model and manufacturer). 

From dereton33

Buying Guide

When you buy radiators, there’s no valve included. It’s because there is no one-size-fits-all solution… every home and lifestyle has its texture. So, before purchasing radiator valves, consider the size, shape, and finish that suits you. Also, radiator valves come with different structures like straight, angled, and H-block. Depending on your pipework and radiator, you have to choose the perfect fit. For a clear idea, follow the table below:

Radiator Inlet

Pipework Through Wall

Pipework Through Floor


Angled Radiator valve

Straight Radiator valve







If you’re still confused, then don’t hesitate to contact Plumberstar. Plumberstar will listen to your problem and give you a better solution with a suitable radiator valve.

trv valve manifold
trv valve manifold

Things to Remember

Remember and follow these things to get a better experience using thermostatic radiator valves:

· Don’t attach a TRV to a radiator in a room if there’s already a wall-mounted thermostat. Therefore, they’ll fight together to heat the room.

· Don’t install a TRV in bathrooms or shower rooms. It’ll get confused about the extra heat of the shower or bath.

· Check them at least once or twice a year to make sure they’re working well or not.

· To get the better performance of TRVs, don’t forget to check the heating systems.

To Sum Up

In short, installing new radiators is a great way to increase your heating system’s comfort and energy efficiency. However, the radiator valves you choose will have a significant impact on the performance of your radiator.

Buy radiator valves from Plumberstar to get the latest, best matching, and top-quality products. In addition, there are all types of brass valves available in Plumberstar. So, what are you waiting for? Go and grab yours because they are not just valves. They are your comfort and happiness.

radiator valve test
radiator valve test

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