Summary: Learn how to bleed radiators, bleed a radiator to let the trapped air out.
If you find that your central heating system isn’t warming your property as well as you would like, you may need to check that all of your radiators are working properly. If you come across a radiator that is warmer at the bottom than at the top, you have a radiator that has trapped air, preventing the water to flow freely. You will need to bleed the radiator in question, which is a process that allows the excess air to be released from the system.