Central Heating Systems, over time, can get air in them.
This has some negative impacts for the efficiency of your heating system – as your radiators don’t radiate so much heat – as a section of what should be hot water, inside the radiator, is, instead, just a pocket of air.
But, worse than that, the air in the heating “loop” can also prevent your boiler from working at all, as the boiler is designed to heat water, not air, and the pumps are designed to pump water, not air and… well, you get the picture: water = good; air = bad.
Some Signs Your Central Heating System Has Air In It
If your central heating system has air in it, you will want to bleed your radiators, but how will you know if you have air in your system?
Below are some sure-fire signs you have air in your central heating system:
- A radiator feels hot at the bottom but cold at the top;
- When your central heating fires up, you hear clanking and bubbling sounds.
If you have any of the above symptoms, or you just suspect that you might have a little air in your central heating system, you should think about bleeding all of the radiators in your system.
How To Bleed a Radiator
Bleeding a radiator is really simple, all you need is a Radiator Key, which is a tool with a square shape at the end. It is designed to turn the square shaped bleed valve which you will find at the top of your radiator on one or both sides.
- Turn off your central heating system – bleeding works best if it is cold, and a system which is turned on can actually draw air in – not the desired effect at all!
- Get a tissue or old rag, and your radiator key;
- Open the valve on the radiator, with the tissue placed underneath it;
- You should hear a hissing noise as the pressure in the central heating system pushes the air at the top of the radiator out;
- After some time, you will get water dribbling out, when it comes consistently (with no air bubbling out) close off the radiator valve again;
- You are done with this radiator, move onto the next one!
You will find that the radiator at the highest point in your system will have the most air in it (air sits on top of water, remember!) but you should still bleed every radiator to get rid of all that pesky air, and make your central heating work up to its maximum – you’ll be surprised and impressed at how much more quickly your house heats up after bleeding your central heating.
What if Nothing Happens When I Open The Radiator Valve?
If you don’t get anything coming out when you open the valve, you probably need to re-pressurize your combi boiler’s central heating system.
Feel free to ask questions in the comments section, below.