How (and Why) to Bleed a Radiator
Have you ever bled a radiator? If the answer is ‘no’, you’re not alone. Many people have never done it, or don’t do it regularly, and there’s a fair chance they’re spending more on their heating as a result. Here’s everything you need to know about how to bleed a radiator.
What is “bleeding a radiator”?
Bleeding a radiator is the process of letting out any air trapped inside it by using a radiator key to open the valve on top of the radiator. When you turn it, you’ll hear a hissing sound as the air escapes.
Why do I need to bleed a radiator?
Trapped air makes your radiators much less efficient. You can often tell when your radiators need bleeding because they will be cooler towards the top. Another sign that you need to bleed a radiator is when it makes a “clucking” sound. Inefficient radiators mean your heating system is wasting energy trying to heat your house – so bleeding them regularly will help cut your heating bills.
How to bleed a radiator
- Get your equipment: you’ll need a radiator key and a cloth or towel to catch any drips.
- Identify which radiators need bleeding: go through the house and check for cold spots on the radiators, especially towards the top. Listen to them as well: can you hear a “clucking” or gurgling sound? Remember, the radiators will be hot so be careful not to burn yourself!
- Switch your heating off. This is important in order to avoid being scalded and/or ending up with a floor covered with water!
- Beware that water from inside a radiator is often discoloured, so it could stain your floors – especially if you have pale carpets. Put down towels to protect anything that needs protecting.
- Open the valve. The radiator bleed valve is in the end of the radiator, at the top. Insert the key and turn it anticlockwise until you hear a hiss. Don’t get too close as the escaping air could be very hot. A quarter to half turn of the key is all that’s needed; you don’t want to open it completely or water could come rushing out.
- When the air stops coming out of the radiator, close the valve promptly. This will cut the chance of water coming out too.
- Repeat this process on all the radiators.
- Check the pressure of your heating system. After bleeding your radiators, you’ll probably need to repressurise the system. Check the pressure gauge on your boiler; it should read between 1.0 and 1.5 bar – a green section on the gauge usually indicates whether it’s in the right pressure zone. You repressurise the system by turning the tap on the central filling loop; do this slowly. If you go too far and the pressure gauge needle points to red, then there is also a bleed tap on the boiler to help correct this.
Need help?
If you don’t fancy doing this yourself, get in touch today. We’re experts in all things plumbing and can bleed your radiators and repressurise your system quickly and with minimal hassle.