A Step by Step Guide: How to bleed your radiators?

This step by step guide will take you through exactly how to approach bleeding your radiators in the future. Firstly, bleeding a radiator is when you release trapped air from inside the radiator. You will know the radiator is ready for bleeding as parts of the radiator will be cold, so let’s do this.

Step one – Turn the heating on

Turn the heating on so all the radiators heat up around the house. Remember to wait until all the radiators are fully heated as this builds up the pressure in the radiator.

Step two – Finding out which radiators need bleeding

Once you feel step one is complete, go and check all radiators to see if all parts of the radiator are heating up. Be careful – The Radiator can be very hot and you don’t want to burn yourself.

You are looking for cool spots within the radiator, they tend to be towards the top. The cool spots mean that air is trapped inside the radiator and needs bleeding out. Once you’ve located which radiators need attention you’re ready for step three.

Step Three – Bleeding the Radiator

Firstly, which the heating off. This is reversing the process identified in step one so you can handle the radiators without worrying about burning yourself.

Bleeding radiators will require you to have either a radiator key or a flat headed screwdriver.

At the top of the radiator at one end there will be a valve. You can attach the radiator key to the square bit in the centre or put the end of the screwdriver into the groove.  

Hold the radiator key or screwdriver with a cloth and I recommend having another cloth handy to catch any drips of water. Then slowly turn the radiator key or screwdriver anti-clockwise – you should then hear a hissing sound which is a sign that the trapped air is escaping the radiator.  

Once all the trapped air has been released water will then come out so make sure to turn the valve clockwise to avoid any dripping water from the radiator.

Step Four – Checking the pressure

Check the pressure by looking at the pressure gauge on your boiler. If you find the pressure is low you’ll need to top it up. You can do this using the lever or tap on your boiler, known as the filling loop.

That’s it! Congratulations, now you know just how simple bleeding radiators can be!