How to bleed a radiator

Why might you need to bleed your radiator?

Bleeding your radiators will help maintain your central heating system and will keep your home warm and snuggly (and your heating bills low).

The process of heating and cooling water can produce air bubbles in your radiators. As air doesn’t conduct heat as well as water, air trapped inside your radiator can stop it from heating up properly (or at all!). If this is the case, you’ll need to remove the air by bleeding the radiator.

How do you know if your radiator needs bleeding?

It’s recommended radiators are bled twice a year, but you might have to do it more often if air’s been trapped in your heating system. There are a few tell-tale signs that your radiator needs bleeding.

The most obvious indicator would be your radiator not heating up as it should. In this case, check your central heating is on and that your radiator’s lockshield is fully open (turn it anti-clockwise as far as you can to open it). If after a few minutes the radiator is still not heating up, then you probably need to bleed it.

Useful tip: Sometimes the bottom of the radiator will warm up, but the top will remain cold. This is also a sign that there is air trapped in it.

Other signs your radiator is not working properly are more subtle. While condensation is often a result of insufficient ventilation, unbalanced heat in your house can also be the cause, so keep an eye out for mildew. If you notice any, make sure you check your radiators are working properly.

If your radiators are making gurgling, gulping and rattling noises when you first turn on the heating, it can mean there is air trapped inside the radiator.

Bleeding your radiator is a lot easier than it sounds. Once your radiator’s cooled down, it takes only 20-30 seconds to bleed it. Just follow the below steps...