How Do I Bleed My Radiators?

Please note, we can only give you basic advice on this page to do the job yourself. Make sure you use the right tools and protective equipment to avoid hurting yourself or damaging your home.

Tools you’ll need:

• Radiator key

• Old towels

• Container to catch water

• Cloth

1. Switch on your central heating: If it isn’t on already, ensure that your central heating is turned on and that your radiators are fully turned up. Then, simply wait for the radiators to heat up.

2. Check your radiators for cold spots: Once the radiators are fully heated, check over all the radiators in your home to see where any large or small cold spots are present. The severity of cold spots relates to how much the radiator needs bleeding. More cold spots = more bleeding required! We’d suggest wearing gloves at this point to prevent burning your hands.

3. Turn off your central heating: Before beginning to bleed your radiators, turn off the central heating. At this stage, keep your radiator intake valves open.

4. Let the radiators cool down: The safest and most effective way to bleed radiators is to do it once the radiators have cooled down again. This is because there isn’t a risk of boiling water bursting out when the radiators are at their hottest. Once your radiators have settled down, this makes the bleeding process much more effective.

5. Source your tools: Now you will need all the tools we listed earlier. Your radiator should come with a radiator bleed valve key; however, they are available at most DIY stores if you require one.

6. Locate the bleed valve: You will find the bleed valve on one of the ends of the radiator at the top. The bleed valve is a round hole with a square inside it. This area is where air and water will be released during the bleeding process, so we’d suggest placing your towels on the floor below this to avoid any spillages.

7. Unscrew the bleed valve: Place the radiator key inside the square area of the bleed valve and begin turning anti-clockwise. Use the cloth to improve your grip whilst catching any water drips. Only do a quarter or half turn, as opening the valve fully can cause water to pour out at a faster speed. Listen out for a hissing sound, which is the trapped air escaping.

8. Wait until the hissing noise has stopped: Once the hissing sound has stopped, you might start to notice water trickling from the valve. Once this turns into a steadier stream of water, this means that all the trapped air has been released.

9. Tighten the valve: Simply re-tighten the bleed valve with your radiator key and clean up any water drips to prevent rusting in the future. Repeat these steps on each radiator in your home!

10. Turn the central heating back on: It’s time to turn the heating back on to check if the bleeding was effective. All you need to do is make sure your radiators feel hot all over. Sometimes, a second bleed is required for it to take full effect.