6 Easy Steps

If you’ve noticed that your radiator does not heat up as it used to, than you should read this article. It is good to have your system checked every year or so; besides the specialist check up, you can also do things by yourself, like bleeding.

Do your radiators need bleeding?

In order to test whether your radiator needs bleeding or not, you can take the following steps:

• Turn on the central heating system
• Feel the temperature in the lower part of the radiator
• Compare the temperature with that at the top of the radiator

If there is a large difference, the radiator certainly needs to be bled.

What’s the problem?

You get this problem because air accumulates in the hot water system and this will mean that you will not get the full amount of warmth that you are supposed to receive. When you notice that you don’t get the same amount of warmth from your radiator as you used to have, then it is high time you thought about bleeding the pipes.

What’s the benefit of bleeding the pipework?

By bleeding the radiators, you improve your home’s heat efficiency and you could even save money, as well. Because air is not an effective heat conductor compared to water, it can become costly to run the radiator with air inside, since you would not be getting the full efficiency out of your system.

Steps of bleeding the pipework

1. Start with the radiator that is furthest from the system (the amount of air accumulated is highest there). You may have to follow your pipework around your home and draw a picture to work out the order the radiators are fitted.
2. Turn on the heating system and wait for it to heat up (turn the water supply on, in case you turned it off during the year).
3. Wait for the radiators to heat up and turn the central heating system off again. The reason for turning it off again is to reduce the possibility of introducing even more air into the system.
4. Carefully use a bleed key to open the bleed valve; the bleed key is an item that usually comes with a brand new radiator – but you can buy one separately though (the bleed valve can be found at the top of the radiator or on some types of radiators at the back). You can see bellow exactly what a bleed key looks like.

   

5. Put a piece of cloth around the key to catch any water that may escape (handy hint: don’t forget to have a small bowl prepared for any drops of water that escape).
6. Use the key to open the valve; turn the bleeding valve just a quarter first and then round to halfway, half anti clockwise, if still needed; you are going to release the air that is inside the system; don’t get scared – it may sound like an aggressive hiss but it is just the air from the radiator that will be followed by water as soon as all the air escapes from the radiator; once there is only water coming out, re-close the valve with the radiator key.

   

7. Turn the heat back on.

Observation: If the central heating system is a sealed system, you should check the pressure and reduce it. Because there are different pressure levels for different heating systems, you should consult the manuals. Also, sometimes it is necessary to bleed the radiator several times, particularly when you have more radiators in your house; set the pressure, bleed the radiators and set the pressure again. Bleed valves tend to get damaged because they are usually made of soft metals; if you cannot open it with an ordinary bleed key, you should consider opening it with an adjustable spanner.

Safety tip: Because mains water contains a small amount of biological sediment, methane can form inside your radiators. For this reason, keep naked flames away from the area where you are working.

Final Step:

Check for any leakages; it is normal for the pipe connection to wear out or for the valve connection to get loose over time.

If you notice any water leakage around the valve, you should consider either changing the valve or the packing ; if you change the packing, turn off the supply valve first and then retighten the packing.

In case this did not solve the problem, you might consider balancing central heating radiators. If you would like to see a practical demonstration of bleeding a radiator, you can check out this radiator bleeding video demo. Good luck!