Top Tips on Bleeding Radiators

Posted by: Sue Kemp on 24th September 2019

Bracing to Bleed your Radiator

Hopefully we have a few more weeks of warm weather left but as we reboot our heating in readiness for Autumn it’s a good idea to check that your system is working as efficiently as possible.
When you restart the heating, you may well notice that some of your radiators have cold patches or are proving slow to heat up – both are sure indications that they need bleeding. Bleeding your radiators will help ensure maximum efficiency and even heat distribution throughout your home.
The good news is, this is a simple task you can easily carry out yourself…

Why do we need to bleed our radiators?

Air bubbles can get trapped in radiators and this prevents the hot water from circulating effectively, resulting in cold spots at the top of your radiators, so they don’t get as hot as they should. This has an impact on how well radiators heat your rooms and can result in some interesting gurgling noises!

By bleeding the radiator, you release the air that has built up inside, meaning the water can circulate effectively, getting them back to full efficiency and meaning you don’t have to leave your radiators on longer to warm your house up.

How do I bleed a radiator?

You will need a few basic tools to do this. First, you will need a radiator key (or in some cases a flat screwdriver). These are available in most hardware shops if you don’t have one. If you’re unsure what you need, just take in a photo of the bleed valve port (usually located at one of the top ends of the radiator) and they will be able to advise in store.
You will also need a bowl to catch any water that may escape – and it’s advisable to have a towel handy to protect the surrounding area as some systems have cleaning /oiling agents mixed in with the water, which could stain your carpets.

Step 1: Diagnose

Turn on the central heating and make sure that all the radiators are turned up to maximum. You then need to check each one for heat levels and cold spots. It is always worth bleeding any radiators that have noticeable coldness at the top, make strange noises or are taking significantly longer than the others to heat up. If in doubt bleed them all, as this will make sure the system is filled throughout.

Step 2: Take Action

Turn off the central heating, but keep the temperature valves on your radiators open.

SAFTEY ALERT: It is very important to turn off the heating and wait for it to cool down fully before you attempt to bleed any radiator – the water inside can be very hot and could cause harm if you do not allow it to cool.
Once you have everything you need and the radiators have fully cooled down, you are ready to bleed them.

Top Tips:

Have that bowl and towel at the ready;

Start with the radiators lowest in system and work up to the highest in your house – air rises!

As you turn and release the valve with your radiator key (or screwdriver), you will hear a hissing sound as the air escapes. This will be followed by a few liquid bubbles, then a solid release of water. Once the sound stops, and you see water escaping, tighten the valve, making sure to fully stem the flow and wipe up any leaked fluid.

Step 2: Test

Once you have completed the process on each radiator and re-tightened all of the valves, you can turn the heating back on. Check for any leaks, and don’t worry if you need to bleed some radiators a second time – it can take a bit of time for the system to completely fill and fully settle into a state of optimum efficiency.

It’s also important to note that the bleeding process may have an impact on boiler pressure, which can result in some radiators not heating up at all. If this is the case, you should adjust the boiler pressure so it returns to the recommended level (consult your boiler manual or contact us for guidance).

Step 4: Relax

…warm and safe in the knowledge that your system is running at its best.

Carshalton Boilers are here to help

If you have any concerns or would like a heating engineer to come out and advise please contact us today on 020 8395 8060 or visit on Carshalton Boilers Website

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