How to Bleed a Radiator

January 27, 2020 | Radiators

Are your radiators banging and clunking when they start to warm up? Or is your radiator still cold hours after switching the heating on? Either of these problems could mean that it’s time to bleed the radiators in your home. A common question asked by homeowners is how to bleed a radiator, so here, we take a closer look at the process so that you can restore heating and warmth to your home.

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Why Do Radiators Need To Be Bled?

When air gets trapped inside a radiator, it has to be bled to remove it. Air causes radiators to struggle to circulate the hot water and this means that less heat can be emitted and it will take much longer for your home to become warm. Until the radiator is bled and the air is removed from the system, you’ll use more energy and will have more expensive energy bills when heating your home. The good news is that it is relatively simple to bleed your radiators. Just follow these steps and you’ll find that the excess air can easily and quickly be removed from your central heating system.

Bleeding Radiators – Heating On Or Off?

The first thing you need to know when it comes to how to bleed a radiator is whether you should have your heating switched on or turned off. It’s important to always turn the central heating on before bleeding your radiators. Switch the system onto full then wait until the radiators have reached maximum heat.

Take care that you don’t burn your hands as you feel along each radiator to see if you can identify any cold spots. A cold spot indicates that air is trapped inside the radiator, so whenever you find one, that means you have to bleed that radiator. Once you know which radiators require bleeding, you then need to turn the central heating off. Remember to wait until all the radiators are completely cool before bleeding them.

What Do I Use To Bleed My Radiators?

Some of the newest radiators can be bled using a screwdriver. Most, however, will need a radiator key to open the valves. There are different radiator bleed key sizes so you’ll need to check which size is right for your radiators. You can usually pick up radiator bleed keys in DIY stores without any problem.

How Do I Bleed My Radiators?

At one end of the radiator, you’ll see a slot that you can fit a screwdriver or radiator bleed key into. Have a cloth close at hand to hold under this radiator valve. This will catch any water that drips from the valve when you loosen it.  Hold the radiator bleed key or screwdriver with a cloth and slowly turn it anti-clockwise. This will open the radiator’s valve. You’ll hear a sound of hissing. This is the air escaping from the radiator.

Eventually the sound will stop and you’ll see water beginning to leak out. When this happens, turn the key clockwise again to shut the valve. If any water has leaked onto your floor, make sure you wipe it up now. You should always bleed your radiators from the ground floor up. Start downstairs and progress upwards to the top floor.

What Do I Do Next?

After bleeding all of the affected radiators in your home, it’s important to check your boiler’s pressure gauge. Bleeding your radiators can make the pressure of your boiler too low. If it is under 1 Bar or in the red, you will have to rebalance the system’s pressure. If it is over 1 Bar or in the green, you can turn on the heating and check there are no cold spots on any of your radiators. You should carry out full checks on all of your home’s radiators every few months to ensure they don’t need bleeding.

How Do You Know If A Radiator Needs Bleeding?

Now you know how to bleed your radiators, but how do you know if a radiator needs bleeding? There are a few key signs to look out for. These include:

  • The top of your radiator feels cold but the bottom of the radiator is heating as normal. This is a very common indicator that the radiator requires bleeding. If there are cold spots around the radiator, this is another sign that you should bleed it.
  • The whole radiator feels cold. This may not be the most common sign that your radiator needs bleeding, but it does indicate that there could be a problem. If the whole radiator is cold, that means that the hot water floor is restricted and is unable to flow into your radiator. Give us a call today to find out what is causing the problem as it could be something that could get worse with time if left unresolved.
  • You have damp or mould in your home. If your heating is uneven, condensation can start to build up. Over time, this can result in damp and mould around your home. If you have spotted damp, grubby patches on your walls, especially in any rooms which are rarely used, this is an indicator your radiators could need attending to.
  • Your radiators are gurgling and rattling. If air is trapped in your radiators, they may make strange noises like rattling, gurgling or gulping. This could have several causes, but one of the most common is that the radiators need bleeding.

If you’re having a problem with your radiators and you’ve taken all the above recommended steps but bleeding hasn’t rectified the issues, don’t hesitate to call our expert team of heating engineers straight away. We can offer you helpful advice and determine the cause of your radiator problem. Thanks to our expertise, we can fix the source of your radiator issues to restore warmth and comfort to your home.

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