How do I bleed a Radiator?

The VPS 4 Stage Guide to bleeding your Radiator

If your radiator isn’t warm all over and has some cold spots, it won’t be working very efficiently and you will be wasting money.

Therefore you might need to bleed the radiator and this involves releasing air that is trapped inside.

You can bleed a radiator yourself quite easily, and your home should be warmer as a result.

So if your radiator doesn’t feel warm all over, follow the VPS 4 Stage Guide to fix the problem.

Stage 1: Turn your heating on

Go round your house and ensure all your radiators are on.

One all your radiators are on and fully heated before moving to Stage 2. The pressure needs to build up inside the radiator so the air can be forced out.

Stage 2: Discover which radiators need bleeding

Once your radiators are on and hot, go and check each one individually to see if all parts of the radiator are warm.

TAKE CARE – radiators can get very hot – please do not burn yourself.

If you find cool areas, especially near the top of the radiator, this means that there could be air or gas trapped and it means that the radiator needs bleeding – move to Stage 3!

Stage 3: Radiator Bleeding

Now switch off your central heating. This is the reverse of Stage 1 and will allow you to touch the radiators with burning yourself and having a wet carpet.

Bleeding radiators will require a radiator key.

At the top of the radiator, normally on the right hand side, there will be a valve.

Attach the radiator key to the square bit in the centre.

Hold the key and have a cloth ready underneath to catch any water, then slowly turn the radiator key and if any gas escapes you’ll hear a hissing noise.

If there is no more gas to come out, water will start to dribble or shoot out so now close the valve.

Stage 4: Check the pressure

Now check your boiler to check the pressure. If it is too low, you can top up and this can be done by using the lever or tap on your boiler, known as the filling loop.

To test all is now working by simply turn your heating on – wait for the radiators to get warm and ensure there are no more cool spots and the radiators are warm all over.

All done! Radiator Bleeding is now complete!

VPS Plumbing stock a wide range of fittings, products, equipment and technology solutions for plumbers and heating engineers.