Home Remedies: How to Bleed A Radiator

Home Remedies: How to Bleed A Radiator

Why you might need to bleed your radiators

If your radiator isn’t warm all over and has some cold spots, it won’t be working very efficiently and you’ll be paying for your heating without feeling the full benefit. You may need to bleed the radiator, which involves letting out the 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 these steps to fix the problem.

What you will need

  • A radiator key or a flat-head screwdriver
  • A couple of cloths and/or a bowl

How to do it

1. Turn on your heating

Turn on your radiators and ensure they are fully heated before moving onto the next step. This helps to build up pressure and let the air out, as well as enabling you to check which radiators need bleeding.

2. Find out which radiators need bleeding

Feel each radiator to check for cold spots, particularly towards the top of the radiator. Be careful you don’t burn yourself! If a radiator has a cold spot it may need bleeding.

3. Turn off your central heating

When you’ve identified which radiators need bleeding, switch off your central heating so that you can continue without burning yourself or getting water everywhere. This is very important because if the radiator isn’t completely cold, any water that comes out while you are bleeding it could be scalding.

4. Bleed the radiators

Once your radiators have cooled down completely, it’s time to get to work. You will find the valve at one end of the top of your radiator. Attach the radiator key to the square part in the centre, or put the end of a flat-head screwdriver into the groove. Hold the key with a cloth and use another cloth or a bowl to catch any drips as you slowly turn the key anti-clockwise for about half a turn. You will hear a hissing sound if gas is leaving the radiator. Hold the radiator key until the noise stops and water starts coming out.

5. Close the valve

When there is no more gas, water will start coming out and you will need to close the valve. It may come out as a jet or as a dribble depending on how modern your valve is, so be prepared to move quickly! Don’t over-tighten the valve as this could damage it.

6. Check the pressure

Look at the gauge on your boiler to check the pressure. If the pressure is too low, you’ll need to top up the water using the lever or tap on your boiler (the ‘filling loop’). The manufacturer’s instructions will tell you what the optimal level is and give you guidance on how to re-pressurise your boiler. If in doubt about any part of this process, always follow the manufacturer’s instructions, and if you’re still not sure, ask a professional for help.

7. Check your radiators again

To find out whether your work has paid off, turn your heating back on, wait for the radiators to heat up, and check for cool spots again. It’s also a good idea to check that the valves aren’t leaking after you have bled your radiators.

What if it doesn’t make a difference?

You may need to bleed some radiators a couple of times to complete the job. But if you’ve done this and the radiators are still not heating properly, it’s time to call in some professional help. It could be that there is a build-up of rust or sludge in your central heating system, and if that’s the case you’ll need a plumber to take a look at it. At M Wilson Plumbing we are Gas Safe registered plumbing and heating specialists, serving Northampton and surrounding areas. We’re on hand to help with all of your central heating and plumbing needs. Call 07983 138153 or get in touch using the contact form on the right.