How to bleed radiators step by step to keep your heating efficient

What does bleeding a radiator mean?

Radiators work using a circuit of hot water that moves inside them. To be fully efficient, the hot water needs to circulate without any 'bubbles' forming in the system.

However, it's quite common for a little air to get into the system, which, as a result, reduces its efficiency and stops them from emitting heat evenly.

Bleeding a radiator is simply the process of removing these air bubbles to optimise the circulation in the water circuit and make it work more efficiently. In other words, it's removing the excess air from the radiator system to improve the energy performance of the heating system.

This is very important. We must ensure our heating system is working correctly. An efficient heating system will help you save energy and, therefore, pay less on your bill by reducing consumption.

How to tell if your radiators need bleeding

The main symptom is that the radiator doesn't heat up properly, or doesn't do so evenly. It's also common to hear strange noises when you turn on the heating, like gurgling or sputtering sounds, which are caused by air that has built up in the system and needs to be removed. Furthermore, it's important to note other details, such as the radiator taking longer than usual to reach the desired temperature or the boiler pressure having dropped for no apparent reason.

Materials needed to bleed radiators

To bleed a radiator, you don't need complex tools; you can do it with materials we all have at home, such as:

• A flat-head screwdriver or a radiator key (depending on the type of valve).
• A container to catch any water that might come out.
• A cloth to prevent splashes.

With just these items, you can safely carry out the maintenance yourself.

How to bleed radiators step by step

First of all, don't panic. Anyone can do it, and it's a fairly simple process where you just need to be careful with 3 basic things:

• The boiler pressure.
• The water temperature.
• The key for opening and closing the water supply.

Right, let's get to the steps:

1. Check the system

Turn on the heating and run your hand over the top of the radiator. Then do the same for the bottom part. If they are at different temperatures (the bottom is hot and the top is cold), you need to bleed it. Air rises to the top, which is why it stays cold (as it's in contact with air, not hot water).

You also need to have sufficient pressure in the system, so you will need to adjust it on your boiler before you start.

2. Position yourself at the first radiator.

Go to the radiator closest to the boiler. You need to understand the direction the water flows and bleed them in order, from the one closest to the boiler to the one furthest away.

This way, you will ensure they are all bled properly.

3. Bleed the radiator

You will need a container (a large cup will do), and a screwdriver. You can also use a cloth in case any water spills.

Next, find the valve on the upper side of the radiator and follow these steps:

a. Place a container under the valve. Hold a container or cup and place it under the valve. If you look closely, there is a small nozzle where the air will come out, followed by the water, so make sure the container is right underneath it. This will prevent the floor from getting wet when the water starts to come out.

b. Turn the valve screw with a screwdriver. You can also use a coin to open the valve. The valve will open and air will begin to come out, 'hissing' or 'sputtering' until water starts to flow. The stream won't be steady, so you must wait until it is a smooth flow before closing the valve.

c. Repeat this procedure on all the radiators. Remember to follow the flow of the water, radiator by radiator.

4. Restore the boiler pressure

Once you have bled all the radiators, you must check the boiler pressure. You should follow the manufacturer's recommendations, but the pressure should usually be between 1 and 1.5 bar. It is most common to set it at 1.5 bar.

5. Enjoy the comfort of the optimal temperature.

Now all that's left is to check that the system is working efficiently and notice the benefit in your home's heating and on your wallet.

How often should you bleed radiators?

It is recommended to do it once a year, preferably before the cold season begins. It is also advisable to repeat the process if you detect any of the symptoms mentioned or if you have made changes to the system.

Why does the boiler pressure drop after bleeding?

When you release air from the system, some water may also escape, which reduces the internal pressure. That's why it's important to check the boiler's pressure gauge after bleeding and, if necessary, top up the water until it reaches the correct pressure.

How long does it take to bleed all the radiators?

It depends on the number of radiators you have in your home, but in general, the entire process shouldn't take more than 30 to 60 minutes. It's a minimal time investment with a very positive impact on your heating's performance.

Can you bleed the heating system with the boiler on?

It is not recommended. Ideally, you should turn off the boiler and wait for the system to cool down. This way, you avoid the risk of burns and ensure that the air has built up at the top of the radiator, making it easier to expel.

In summary, bleeding radiators is a simple task that improves the system's efficiency, reduces consumption, and ensures a more comfortable winter. With basic maintenance and a good maintenance service, you can enjoy efficient and safe heating.