How to Bleed a Radiator

Before determining whether or not your radiators need bleeding, it is essential to assess which radiators hold built-up air.

Ensure that before deciding which radiators to bleed, you wait for the heating to fully circulate your home.

Once your radiators are fully heated you can assess the temperature of your radiator from top to bottom.

However, it is vital that you take caution during this action. If your radiators are too hot, you can wear thin gloves to prevent injury or discomfort.

Identify whether any radiators are colder at the top or aren’t as warm as others.

It is vital to allow a considerable amount of time for your central heating to cool down.

If you attempt to bleed your radiators before allowing the central heating to cool, you could scold yourself with steam and boiling water escaping from the radiator.

With a cloth or towels, create a protective area surrounding the radiator to prevent water from reaching the carpet or walls.

You can also use a jug or bowl to catch excess water that escapes from the radiator.

Using your radiator key or flathead screwdriver, release the bleed valve on your radiator.

The valve typically requires turning once or twice anti-clockwise. You will know when the valve is open once you hear a hissing sound. This sound indicates the air escaping your central heating system.

99% of the time there is only one bleed valve, but this bleed valve will always be at the top of the radiator.

If it’s a vertical radiator, assess the height risk.

Also, not all bleed valves have a screwdriver slot, but all modern bleed valves do.

• It is not unusual to witness a strong smell when releasing stagnant air from a radiator. This is methane and can be highly flammable.
• Make sure both radiator valves are open and Thermostatic valves adjusted to maximum whilst bleeding .

Your radiator should only require bleeding for up to 20-30 seconds, depending on how much air has built up in your system.

Once the hissing sound starts to gurgle, or water begins to escape from the valve, you know it is time to close it.

This can be closed by turning once or twice clockwise, in the opposite fashion to how it was opened.

After bleeding the radiators in your home, it is a good idea to turn the heating back on to check a couple of things. The first is to ensure that your boiler pressure isn’t too low.

Occasionally, allowing too much water to leave the central heating system can create lower pressure. This will require you to repressurise the system.

Secondly, if your boiler pressure is correct, check whether your radiators are fully heated.

If cool spots persist, this could be an indication of more complex problems. Under these circumstances, you might need a Gas Safe Registered Engineer to professionally diagnose and resolve the problem.

The team at Boilerhut are certified and determined to help you heat your home without any fuss, visit our website to receive professional assistance with your boiler.