Do you need to Bleed your Radiators?

We’ve all heard about bleeding radiators, but is it really important and how do you do it? Basically, air in your radiators can significantly decrease the power, so much so that sometimes entire areas of the radiator no longer warm up at all. So, put simply, it’s actually very important to bleed your radiators in order to maintain heat in your home.

When is it time to bleed your radiators?

There are some clear signs that your radiator may need bleeding. The first one is if you start to hear strange noises coming from your radiators. This can be an indicator of air in the pipes and radiators. This will be particularly obvious if you hear ‘gurgling’ noises. This is a clear sign there are air bubbles in your radiators, and your radiators should not contain any air, only water.

Another clear indication that your radiators may need bleeding is if they do not completely warm up. Typically, the bottom half which will still contain water will still become warm but the upper half, which is likely full of air can be lukewarm or cool but not fully heated. The problem can occur to varying degrees in different rooms throughout the house.

Air can be introduced into a central heating system in several ways. Firstly, it can happen when new water enters the system from the expansion tank or as routine maintenance is carried out. It could also be created by the movement of the pump as it turns. Air in the radiators occurs more often in winter months, so it’s a good idea to bleed your radiators near the beginning of winter, to ensure they are working correctly for the start of winter.

How do you bleed your radiators?

When it’s time to bleed your radiators, you’ll be pleased to learn it’s not difficult. Basically, you’re aiming to release air from the radiators in order to increase the efficiency of your heating system. Here’s what you need to do in order to do this:

1. Firstly, you’ll need a radiator key and a container to catch the water released. If you don’t own a radiator key, you can purchase one at most hardware stores.
2. Make sure you turn on all the radiators to the maximum temperature, wait for a while and then turn off the central heating and let them cool down. It’s very important to turn off the central heating, because some water pumps, depending on where in the system they are fitted, will actually suck more air into the radiator and consequently the heating system, if they are turned on while you open the bleeder valve.
3. There is a square ‘bleed screw’ at the top of the radiator and this is where the air and water will be released from, so make sure you put your container beneath this area on the floor.
4. Open the bleeder valve and allow all air to escape. Please be aware, there will always be some water so don’t worry about this. Once all the air is out, you can close the valve and repeat the process for all radiators.
5. Wipe down any water which is on the radiator to avoid rusting and move on to the next radiator.
6. You should start with the radiator closest to the boiler and do them one at a time.

It may be necessary to bleed some radiators more than once. If this still doesn’t fix the problem, you may need a professional engineer to inspect the system. We will be happy to advise, assist or come to your house and complete the process for you if needed!