Which radiators should you bleed first?

17 January 2023
Which radiators should you bleed first?

Which radiators should you bleed first?

A man bleeding a radiator with a flathead screwdriverA man bleeding a radiator with a flathead screwdriver

Bleeding a radiator is one of the easiest DIY heating tasks you can do. However, there is a method to bleeding radiators to ensure you get maximum benefit to your heating system.

In this article we'll show you how to bleed a radiator and which radiator is best to bleed first.

Why do you need to bleed a radiator?

Firstly, it's good to establish why your radiators might need bleeding. It usually needs doing when air gets trapped in your central heating system, which can happen from time to time.

The best way to test out if you have air in your system is by switching on your central heating to maximum and allowing your radiators to get to their full temperature.

Go round each radiator and carefully feel if there are any temperature differences across the surface of the radiator.

If a radiator feels cool at the top and warm at the bottom, it probably has air trapped in the top of it and needs the air bleeding out of it.

If it's just one radiator that has these symptoms then you might be able to get away with just bleeding that radiator. However, it's best to bleed all the radiators in your home to ensure you release all the air and don't have to repeat the job again for a while.

The radiator to bleed first

Making sure your central heating is switched off, you should start with a downstairs radiator that is the furthest away from your boiler.

Work your way through the radiators getting closer to the boiler, then go upstairs and repeat the process.

If you live in a bungalow, then just start with bleeding the radiator at the far end of your property in terms of its distance to your boiler.

How to bleed a radiator

In the helpful video below, Jimmy the plumber shows you how easy it is to bleed air out of a radiator.

All you need is a brass radiator key (or a flathead screwdriver) and a cloth to catch any drips of escaping water.

Please ensure your heating system is switched off and had a chance to cool down before starting this job.

NOTE - if you have a double panel radiator, you might have two bleed valves - one on each panel. Follow the same process and bleed both.


Heating system maintenance

Once you've bled all your radiators, switch on your central heating and you should find that all of your radiators are heating up evenly and fully. If this is not the case, it's probably worth getting in a professional heating engineer to look for any deeper problems.

Likewise, if you find that you're having to bleed your radiators on a regular basis, there's clearly a leak in your system where air is coming in. Again, this would be time to get in a professional.

It's a good idea to get your heating system inspected every 12 months. A heating engineer can come in, service your boiler, top up your chemical inhibitor levels and generally ensure your system is in good working order.

Annual heating maintenance is the best way to keep your heating running smoothly, efficiently (keeping your heating bills down) and making sure it your boiler doesn't break down at the coldest time of the year when you most need it.

Related posts