Your Guide to Bleeding Your Radiator

Your Guide to Bleeding Your Radiator

Air bubbles in your central heating system can hinder hot water circulation, preventing your radiators from heating effectively and slowing down the overall heating process. Trapped air can also lead to loud, irritating noises, which may indicate a more serious issue. Bleeding your radiators can resolve these problems, and we’ve put together some simple tips to help you do it quickly and easily.

How Often Should You Bleed Your Radiators?

It’s recommended to bleed your radiators at least once a year, ideally at the beginning of winter. This practice ensures your heating system operates at its best capacity.

Signs Your Radiators Need Bleeding

After your radiators have heated up, check for any cold spots. If you feel cool areas, this may indicate trapped air inside the radiator. Bleeding should resolve this issue.

Additional Checks Before Bleeding

Before you begin bleeding your radiators, ensure the thermostatic radiator valve (TRV) is fully open and not obstructed. The TRV is typically located at the top or bottom of the radiator. Also, inspect your radiators for rust or potential leaks, as these may signal more significant problems beyond trapped air.

Preparing to Bleed Your Radiators

1.    Turn off the heating: Ensure your heating system is off and the radiators are cool enough to touch.

2.    Identify radiators that need bleeding: Look for cold spots to determine which radiators require attention.

3.     Gather your tools: You’ll need a radiator key (available at most DIY stores) or a screwdriver for newer models, along with a cloth and a tray or pot to collect any water.

The Bleeding Process

1.     Position your tray: Place your tray or pot below the valve to catch any water.

2.     Insert the radiator key: Insert the key into the valve grooves.

3.     Twist to release air: Using a cloth to protect your hands, turn the key counterclockwise. You should hear a hissing noise as air is released, followed by water flow.

4.     Close the valve: Once water drips steadily and the hissing stops, turn the key clockwise to close the valve.

5.     Check for leaks: Ensure no water has spilled onto the radiator to prevent rust.

6.     Repeat: Move on to the next radiator and repeat the process.

After Bleeding Your Radiators

Once you've bled all necessary radiators, turn your central heating back on and check that your boiler displays the correct pressure. If the pressure is too low, use the filling loop according to your boiler’s manufacturer instructions. Also, ensure none of the bleed valves are leaking. 

We also have a handy video with a radiator problem solving checklist to assist you further with common radiator issues.

If the Issue Persists

Sometimes, a radiator may require a second bleeding to resolve the issue. If problems continue, it’s crucial to contact a Gas Safe engineer. Our expert engineers at Sureserve are all Gas Safe registered, so you can trust that you’re in good hands. Contact us here.

How to Confirm It Worked

Check that all your radiators are heating evenly. If you still hear noises, this may be the normal sound of cooling and condensing system water. However, if cold spots persist, you might be dealing with sludge buildup, which requires removal and treatment.

We are here to support you, if you need further help with any of the above, please contact us here.