Updated on 12th September, 2023 by Martin Astley
When cool breezes surround you in winter, your radiator saves you from shivering and keeps your home warmer. Radiators are crucial to your central heating system; they equally distribute heat around your home.
But what if you turn on your radiator and notice it is not working correctly, the reason being a faulty valve? Due to this, you decide to replace it, but like most people, you don’t know how to change it. But no need to worry; we will tell you how to change a radiator valve yourself in this article.
Understanding Radiator Valves
Radiator valves are simply the components that control the flow of hot water that enters and exits the radiator. Valves play an important role in maintaining the radiator’s heat. You can turn down the valves in rooms where you don’t require heating, saving energy and money.
Valves are usually located at the radiator’s bottom, left or right. In traditional radiators, valves are connected to a water pipe that comes from the floor, but if we talk about modernised radiators, the valves are fitted from the wall.
You will find two different valves on your radiator; one is the manual valve that controls the hot water that enters your radiator. The other is the lock shield valve, which balances the system by controlling the radiator’s heat.
Different Types of Radiator Valves
Although you will only find two valves on your radiator, as mentioned above, one is a lock shield and the other is a manual valve. But these valves are further divided into different types and styles, which are discussed down below:
1. Manual Valves
These are the basic valves found at the bottom of your radiator. It allows you to control the amount of heat you want your radiator to emit.
They operate like a tap. To regulate the temperature and turn it up, you will have to turn the valve anti-clockwise manually; to close it up, you will have to turn it clockwise.
Manual valves are very easy to use and are totally under your control. The only drawback is that the manual adjustment makes it less energy efficient, as it depends on how much you turn it up and down.
2. Lockshield Valves
The second most common type of valve is the lockshield valve. These valves aim to control the amount of water that moves out of the radiator.
Lockshield valves are crucial to balancing your radiators. When the water flows around the central heating system, it gets hotter when it comes close to the boiler, meaning that the radiators near the boiler will receive more hot water than the radiators located further away.
In this situation, the lock shield valve ensures that hot water flow among your home’s radiators is equally distributed.
3. H Block Valves
H blocks are H-shaped valves for radiators with middle inlets responsible for joining pipes and valves at the inlet. They are further divided into two types: angled H-blocks and straight H-blocks. Although uncommon in the UK, they can be found in TRV, manual, and lockshield valve varieties.
4. Angled and Curved Valves
Angled or curved valves are used when the pipe needs to be turned or bent at a 90-degree angle to enter the radiator. They are useful when central heating pipes come directly out of the floor. An angle valve provides a neat and clean finish and minimises pipework.
5. Smart Radiator Valves
Smart radiator valves are used in the smart heating system, working side by side with smart thermostats, allowing users to adjust the temperature settings from anywhere with the help of an app that can be installed on their smartphones, tablets, and computers. They provide room-by-room control of heating flow and help create a zoned heating system.
6. Straight Valves
Straight radiator valves connect the hot water pipes of your central heating system to your radiators that are parallel to each other. A straight is needed when your pipes run through the wall into your radiators.
7. Thermostatic Radiator Valve
A thermostatic radiator valve is an attachment that you put on your valves to control the heating temperature around your home. To operate it, you need to set a particular temperature level.
Once the desired temperature is reached, water flows into your radiator and stops. This allows you to set different temperatures for different rooms, ensuring your home remains comfortable without wasting unnecessary energy.
Reasons for Radiator valve replacement
Reasons to change your radiators valve could be multiple:
- The first and foremost reason is that your radiator valve has become faulty. A faulty or damaged radiator valve can interrupt the heating flow around your home, causing a lack of control over the heating temperature in your home’s different rooms. Also, a damaged radiator can cause water to leak from it.
- The second reason is that you want to upgrade your manual thermostat with a thermostatic radiator valve. As mentioned above, thermostatic radiator valves provide you with control over the temperature flow in your home. It allows you to set different room temperature settings and minimises energy waste.
- The third and last reason is decoration. Maybe you are planning to redecorate your home or get it repainted. Because of this, you might want a valve that complements your home’s design and colour scheme.
Tools you need to change your radiator’s valve
If you have decided to change your radiator valve and are looking for guidance regarding the whole process, then you will find it in this article. Still, before that, you will need certain tools that you will need to gather first before starting the bleeding process. The tools are the following:
- Pair of gloves.
- The radiator bleeds the key.
- New valve (TRV, smart valve, etc.).
- A plastic or steel bowl to collect water.
- A towel or piece of cloth to clean up the mess.
- Jubilee clip
- Adjustable spanners or pilers
- Wire wool for cleaning pipes
- PTFE tape for protection against leaks (optional).
Step-by-Step Guide: How to replace a radiator valve
1. Turn off your central heating system and water supply
After gathering up the necessary tools, the first step you need to turn off your central heating system and water supply is crucial to ensure that while changing your radiator valve, you don’t get exposed to accidental hot water spillage, as this can cause you injury, which we don’t want. So be safe and completely shut off the system by turning off everything electrical, turning down all the thermostats, and ensuring the system doesn’t start.
Note: This step can be easily performed if you have a combi boiler. But for a conventional boiler, you must contact a Gas Safe engineer.
2. Prepare for the mess by laying down towels or cloth
You must stay prepared for the potential mess. Lay down towels or cloth and place a bowl to catch the water spillage from your radiator valves. Also, prepare the valves (the one you will remove and the one you will install). Then remove the nuts and connectors of the new valve so that you can easily fix it to your radiator.
3. Bleed and Drain your Radiators
After preparing for the mess and your radiator valves, drain and bleed out your radiators to remove any trapped air or remaining water. To do that, you will need a bleeding key and attach it to the radiators farthest from your boiler.
For more details regarding bleeding the radiator, please read our blog: How to Bleed a Radiator.
When you are finished bleeding your radiators, find the draining valve of the radiator located at the lowest point in your home, generally the first floor.
After locating the radiator, look at the bottom for the draining valve. Use your hose pipe and attach it to the valve.
Also, use the jubilee clip to tighten the hose pipe so it does not slip and create a mess.
Ensure the water removed from your radiator from the hose pipe doesn’t end up in your garden and lawn, as the water inside the radiator contains chemicals that can harm your plants and lawn.
Related article: How to drain your central heating system.
4. Remove the Old valve
Now, after bleeding and draining your radiators, remove the old valve. First, hold the valve’s body with the help of a wrench.
Then loosen up the nuts on the valves with a spanner and turn them anti-clockwise. After loosening the nuts, clean up the pipes with wire wool. You will also face a situation in which the valve you replace with your old one will have different cap sizes.
Don’t worry about this situation, as you will have to remove the olives, which are small ring-shaped pipes that can be easily removed by unscrewing them with the help of a screwdriver.
5. Install the new valve
After removing the old valve, it is time to install the new one. To do that, you must fit the radiator tail where the old valve was released.
Also, use PTFE tape to tighten it up to avoid potential leakage. Then fit the new valve body by connecting it to the water pipe and placing it into the radiator.
After successfully placing the valve’s body, tighten the nuts with the help of adjustable spanners.
6. Turn back on your water supply
After installing your new valve, it’s time to turn your water supply back on and bleed out your radiators again. Before that, you must close all the valves and note the movements. Then fill out the system and keep an eye out for leaks.
After filling your system with no leakages, you must bleed out the radiator again. It is crucial to bleed out the radiator to remove any trapped air inside and prevent them from getting cold spots. You may also need to repressurise your system to ensure everything works fine.
How to change a radiator valve without draining the system
To remove a radiator valve without draining the system, repeat the steps mentioned above, which include:
- Shutting off your central heating system.
- Prepare for the potential mess by laying down the towels or cloth.
- Remove the air from the radiators with the help of a bleeding key.
- Remove the old valve by holding it with a wrench and loosen the nuts using a spanner.
- Then make sure you have placed a container to catch the remaining water.
- Install the new valve by following the instructions provided above.
- Then repressurise your system and bleed out your radiators once again.
How much time does it take to replace a radiator valve?
Firstly, it depends on your boiler and your experience. If you haven’t replaced or bled out your radiator, the process might take 40–45 minutes.
And if you are experienced with valves and other components of your radiators, If you frequently bleed your radiator, the process can take 30 minutes.
After reading this article, I hope you can replace your old valve with the new one. But before you do that, remember to fully understand the valves you have installed and the type you want to install.
Don’t forget to gather the necessary tools mentioned above. If you face difficulty performing the above steps due to a lack of experience, contact a gas-safe engineer immediately.
However, if you want any assistance or need your queries answered, contact 24|7 Home Rescue by calling us at 0345 3192 247.