How to Bleed a Radiator

If you feel like your radiators are failing to heat up properly, or you’ve noticed that they have cold spots, you may need to bleed them. This is a fairly simple process that can keep your house warm and your heating bills down. Our plumbers have put together a step by step guide.

Why Might They Need Bled?

Radiators can get air trapped inside them, which can stop the warm water circulating around them, resulting in less heat output. This will mean the effectiveness of your central heating system is reduced, and it will mean your heating bills will increase. You may also notice banging noises coming from your radiators, this is another sign they need bled.

How to Bleed Your Radiator

You will need: 

• A radiator key (you can get these from DIY stores)
• A cloth/ rag/ towel to catch any water.

The steps:

• Turn off your central heating, the radiators need to be cold to the touch before you start.
• Use your radiator key to turn the valve at the top of the radiator, you need to slot it into the square groove in the centre of the valve. 
• Start to turn it anticlockwise and you should hear a hissing sound, this is the trapped air escaping, use your cloth to catch any water that comes out.
• Retighten the valve once the hissing stops and only liquid comes out, you need to do this quickly to avoid too much water escaping.
• Turn your central heating system back on.

Keep an eye on the boiler, to check the pressure. Bleeding the radiators can cause the pressure to drop. If the pressure is too low you will need to top it up. To do this use the filling loop button on the radiator. 

Once the boiler has been on long enough, go round and check your radiators, they should be warm and the heat should be evenly spread.

If you have bled your radiators and the problem is persisting, get in touch with one of our plumbers. You may have a different problem, that bleeding won’t fix. Our plumbers are on hand to help.