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As we are settling into the winter period, chances are your heating has been on for a while now and however you choose to heat your home, if you have radiators it’s always good to check they are warming up properly. 

If you’ve noticed banging coming from the pipes or the top part of the radiators are cold when the heating is on, then they will most likely have air inside which will need ‘bleeding’ out. 

Removing the air is simple and can really help the efficiency of your heating system. 

Let’s do one step at a time

Step One

You’ll need a radiator key. These can be picked up from most DIY/hardware stores and are cheap to buy with prices as low as 0.79p. 

Radiator Key

Step Two

Grab an old towel and/or tub to catch any water that leaks when removing the air. 

Step Three

Identify which radiators have cold spots by switching your heating on and allowing each radiator to warm up to be checked.  

Step Four

Switch the heating off and allow to cool. 

Step Five

Start with the ground floor. Find the radiator furthest from the boiler and locate the bleed valve, which is usually at the top side. 

Step Six

Place a container beneath the valve on the floor & hold a cloth under the valve. This is to catch any water that may leak and will protect the floor. 

Step Seven

Insert your key into the valve and make sure it’s locked in place. Slowly turn anti clockwise to open the valve. Try not to open the valve fully as this may cause water to escape. 

You should hear a hissing noise which is the air escaping, once this has stopped and you have water starting to leak out, close the valve, but try not to close it too tightly to avoid damaging the valve.

You have now bled all the air from the radiator.  Repeat these steps with all remaining radiators, completing the ground floor first. 

Step Eight

Once all the radiators have been bled, check your system pressure. 

Top Tip

It’s important to make sure the pressure is set correctly. Check your boilers/heating systems manual to find the optimum pressure but it’s usually between 1.2 and 1.5 bar. 

To increase the pressure, you’ll need to add cold mains water to the system and can be done using the filling loop. Some are located internally, some externally. 

Using the black valves on the filling loop, open them up and you’ll see the pressure gauge starting to rise, once this gets to the correct pressure, close both valves.

Typically, the pressure should only need topping up a couple times of year, if you need to top up more often, contact a reputable plumber to check it over.

Has this been useful? We would love to know. Comment and tell us how you get on.