Bleeding Radiators FAQ

Bleeding a radiator is the most straightforward most, common and maybe most essential plumbing job.

Every homeowner should know how to bleed their radiator.

Here are the most common ‘bleeding a radiator’ questions and answers.

How do I bleed a radiator?

Please take a look at our guide on how to bleed a radiator

What key do I need to bleed a radiator?

You need a radiator key to bleed your radiator they are all standard size and will fit any radiator.

Where do I buy a radiator key?

You can buy a radiator key from your local DIY shops such as B&Q, Screwfix and Toolstation. You can get them online from places such as Amazon and eBay also.

Is it possible to bleed a radiator without a key?

In some instances yes modern radiators can be bled with a flat head screwdriver. However, radiator keys are easier to use, easily obtainable and very cheap so there really isn’t any reason to bleed your radiator without a key.

Can you bleed a radiator when the heating is on?

You can, but it’s not advisable as you can burn yourself with hot water.  Feel free to turn your heating on to establish which radiators need bleeding but switch them off and allow them to cool before bleeding.

Why do you need to bleed a radiator?

As water circulates through the central heating system, air will inevitably get trapped inside, which prevents water from reaching some parts of the radiator (the top-down). Now the radiator doesn’t get hot in places, making it less efficient, giving you a colder room and wasted energy.

Which radiator should I bleed first?

Bleed the downstairs radiators first. Start with the one furthest away from the boiler. If you live in a flat or bungalow, start with the radiator furthest away from the boiler.

Should water come out when you bleed a radiator?

Yes once the air is fully released water will come out. Make sure you have a cloth handy to catch excess water. It’s very common for radiator water to be a dark colour which can stain your walls and carpets. Once the water’s released instantly screw the valve back up to prevent any more escaping.

How often should I bleed a radiator?

At least once a year the best time is when your heating goes on at the start of winter. Bleed your radiators whenever necessary after that.

I’ve bled my radiators, but they are cold at the bottom?

You have a build-up of sludge and debris in your system bleeding will not remove this your system will need power flushing

Will TM Hughes & Son bleed my radiators for me?

If you’re unsure about bleeding your radiators and would like your system balanced properly then yes certainly give us a call.