🕑 8 minutes read

Are your radiators feeling colder at the top and lukewarm at the bottom? Do you hear gurgling noises or have cold spots on your radiators?

Bleeding your radiator is an essential home maintenance task that ensures your heating system operates efficiently. If you've noticed cold spots on your radiators or a lack of heat in your home, it might be time to bleed them.

This serviceteam guide will walk you through the process step-by-step and answer common questions about radiator bleeding.

[Step-by-Step Guide]

What Does a Bleeding Radiator Mean?

Bleeding a radiator means getting rid of extra air stuck inside it. When air gets trapped in a radiator, it stops the hot water from heating up the top part of the radiator. This makes the radiator less effective and can leave rooms feeling cold.

When you bleed a radiator, you're not getting rid of the water inside it, just the air. It's a quick process that only takes a few minutes, but it can make a big difference in how well your heating works and how warm your home feels.

How Do I Know If My Radiators Need Bleeding?

Many homeowners can tell when their radiators need bleeding by watching for common signs. If your radiators are not heating up properly or if you notice cold spots and family members start complaining about the cold, it may be time for a bleed.

Additionally, if you notice an odd noise emanating from the radiator when the heating is on, like gurgling, this is also a sign of trapped air that needs to be released.

If your radiator is too old, we advise you to opt for a radiator replacement.

How Do You Bleed a Radiator?

To bleed a radiator, you need to release any trapped air. To do this, open the radiator bleed valve slightly and allow the air to escape until water starts to drip out. Once water appears, tighten the valve to stop the water flow and prevent leakage.


Check out our blog on radiator leaks to learn how to avoid the inconvenience they cause.

Here's the step-by-step guide on how to bleed a radiator

  • Gather the necessary tools, including a radiator key or flathead screwdriver, a cloth or towel, and a container to catch any water.
  • Turn off your central heating system to prevent hot water from spilling out, and ensure that your radiators are completely cool.
  • Then, feel the top of each radiator for any cold spots, which may indicate trapped air.
  • Locate the bleed valve, usually found at the top of the radiator.
  • Place the container under the bleed valve to catch any water.
  • Slowly turn the valve anticlockwise using either the radiator key or a screwdriver. As air escapes, you should hear a hissing sound.
  • Once water starts to drip steadily, close the valve by turning it clockwise.
  • Use a cloth or towel to wipe away any extra water.

Is It Okay To Bleed a Radiator When The Heating Is On?

No, it's not safe to bleed a radiator when the heating is on.
Radiators contain hot water and air, and when you open the valve to bleed them, this hot water and air can escape.

If the heating is on, the water and air inside the radiator are very hot, and if released, they could cause burns.

It's essential to ensure that your heating is turned off and the radiators have cooled down before attempting to bleed them.

How Long Does It Take To Bleed a Radiator?

Bleeding a radiator usually takes about 30 seconds.
However, the time can vary depending on the radiator's size and how much air is trapped inside. Even if there's a lot of air, it shouldn't take more than half a minute. After bleeding, hot water will flow through your heating system quickly.

What Tools Do I Need to Bleed My Radiator?

Depending on the type of bleed valve your radiator has, you will need a radiator key or a screwdriver. A bowl or cloth to catch any water that escapes is also recommended, and you may want a towel to clean up any spills.

What Happens After You Finish Bleeding Your Radiator?


After you finish bleeding your radiator, turn your central heating system back on and check that the radiators heat up properly. You should no longer hear any gurgling noises. If problems persist, you may need to bleed the radiator again or consult a professional.

First, you need to perform some essential checks to ensure your efforts are successful. Start by checking the boiler pressure, aiming for a range of 1.0 to 1.5 bars when the system is off and approximately 2 bars when it's on. If the pressure is too low, you'll need to re-pressurize the boiler, which is simple.

Once the pressure is correct, turn the heating back on and check all your radiators again. They should all function correctly and provide even warmth throughout your home. With everything in order, you can relax and enjoy your cosy home once more.

What Is the Best Way to Bleed a Radiator?

To ensure you are bleeding your radiators correctly and efficiently, follow these best practices:

  • Work systematically from the bottom to the top of your home, starting with the radiator closest to the boiler.
  • Bleed each radiator until all the trapped air has been released, and water flows out steadily.
  • Use a radiator key rather than a screwdriver, as it is specifically designed for the job and is less likely to round off the valve.

Looking For a Professional Radiator Service?


How to Bleed a Radiator Without a Bleed Valve?


If your radiator doesn't have a bleed valve, it may be an older model that requires a different approach. Before contacting a plumber for assistance, inspect your entire radiator for the bleed valve.

In some cases, the valve may be concealed under layers of paint or located on the back face of the radiator. If you're unable to locate the bleed valve, it's advisable to seek help from a professional plumbing engineer who can provide alternative solutions. They can replace the outdated valve with a modern one, ensuring both safety and efficiency in your heating system.

Can I Bleed a Radiator With a Screwdriver?


Yes, you can use a flathead screwdriver instead of a radiator key to bleed a radiator. Insert the flat head into the notches of the bleed valve and turn it anticlockwise to open the valve. Clockwise turns will close the valve. Make sure to have a cloth or jug ready to catch any water that comes out.

How to Check You've Bled Your Radiators Properly?


After bleeding your radiator, check if the top heats up evenly and the gurgling noises stop. If issues persist, it might signal a larger problem needing professional attention.

A successful bleeding won't lead to a significant drop in boiler pressure. If it does, refer to our guide on increasing boiler pressure.

Avoid fully opening the valve, as it could cause a sudden drop in boiler pressure.

How Often Should You Bleed Your Radiators?


Radiators should generally be bled at least once a year to ensure they're working efficiently. However, if you notice any signs of cold spots or inconsistent heating, it's essential to check and bleed them as needed.

Bleeding your radiators helps maintain your boiler's efficiency, making sure your home stays warm, and your energy costs stay low. We recommend bleeding your radiators every few months as part of regular maintenance.

Additionally, it's beneficial to bleed your radiators after long periods of inactivity, such as at the end of summer.

Regularly bleeding your radiators will ease the strain on your boiler and ensure proper heating throughout your home.

Is My Radiator Broken, or Does It Just Need Bleeding?

Sometimes, radiator issues may indicate a larger problem in your heating system.

If you've bled your radiators and they still don't heat up properly, there could be corrosion, blockages, or issues with your boiler or pipework. It's best to get a professional to take a look.

In conclusion, bleeding your radiators is a simple process that can make a big difference in the efficiency of your heating. It's a good practice to do this regularly to ensure your home stays warm and that you spot bigger issues that could cause problems down the line. Stay warm, and keep those radiators in top shape!

How Much Does It Cost To Bleed a Radiator?

Bleeding your radiators by a professional typically costs between $100 and $200.
This service involves removing trapped air from your radiators. It's a simple and affordable solution if your radiators are making noise or not heating properly.

Call Serviceteam Professionals


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Here's why:

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If you're facing issues with your radiators or need boiler repair, installation, or maintenance services in London or its surrounding areas, don't hesitate to contact us. You can make a booking online or give us a call, and our friendly customer service officials will answer any questions you may have.