How to bleed a radiator?

Jan 06, 2020

What does bleeding you radiators mean?

In simple terms it means letting the air out of the radiator/s. Over time trapped air is unable to escape and is pushed around your heating system eventually settling in your radiators.

How do I know if my radiators need bleeding?

You will notice after turning the heating on that a radiator may still be cold at the top and hot at the bottom. This would indicate that air is present in your radiator.

How do a bleed a radiator?

Follow these 5 steps on how to bleed a radiator.

Step 1 – Turn off your heating

DO NOT BLEED you radiators with your heating system on. The water will be hot and you may burn yourself. Make sure you also prepare the area near the radiator with old towels as the discolouring of the radiator water could ruin your carpet, rug or curtain.

Step 2 – Find your radiator key

You will need a radiator key to enable you to bleed your radiator. If you don’t have one, you can buy one from most DIY shops or even the £1 stores.

Step 3 – Open the radiator valve

With a towel or old rag ready, insert your radiator key into the bleed valve (see image below to know where). Turn it slowly anti-clockwise (to the left).
You should hear a hiss sound and that is the air being “bled” out. If you only see water then turn the key clockwise (to the right) and close it.

Step 4 – Repeat process

Repeat this process with all the radiators. If you must bleed all the radiators, start at the bottom floor of the house and work your way up to the top floor radiators.

Step 5 – Check you water pressure on your boiler

Once you have completed bleeding, on all or some of your radiators, you may need to check the pressure on the boiler. Releasing air from the heating system will be replaced with water thus reducing water pressure in your heating system (If your system is unvented) You will need to add water back in to the system via a filling loop. If your system is vented (tanks in the loft) then the water should be replaced automatically.

A typical heating system will have a pressure of 1.0 to 1.5 bar. If the system falls below 1.0 bar top up the pressure by locating the filling loop, looks like a tap (usually blue) and is connected to your mains water supply.

If unsure, call your local heating engineer and they will be happy to do this for you. Please note some companies will charge for this service.

If you need your heating system serviced, we offer a full heating system check. We will service your boiler, check your water and gas pressure, bleed all your radiators and provide a visual inspection of your tank.
For more information feel free to contact us

If you would like your heating system assessed or would like to get your boiler serviced you can contact the team at A Heating on 01933 428 770

How to bleed a radiator?

Jan 06, 2020

In this post, we will help you understand on how to bleed your radiators.