How to bleed your radiators
Bleeding your radiators. To those not in the know, that sounds like it could be quite difficult to do and best left to professionals. However, it’s a relatively simple process and if you’re confident performing handy jobs, it could save you the cost and hassle of calling someone in to do it for you. With that in mind, we’ve put together this handy guide to help you know how to bleed your radiators.
Step 1: Turn your heating on
Remember to wait until your radiators are fully heated as you need to build up the pressure inside the radiator to be able to force the air out.
Step 2: Find out which radiators need bleeding
Once your radiators are hot, check each one individually from the top to the bottom checking for inconsistencies in warmth. Be careful as radiators can get very hot and you don’t want to burn yourself.
Cool spots, particularly toward the top of the radiator, mean that there could be air or gas trapped and that you’ll need to bleed that radiator.
Step 3: Bleed the radiators
Switch off your central heating. This is reversing the process identified in step one and will allow you to handle the radiators without burning yourself or soaking your floor.
Bleeding radiators will require a radiator key (buy one at your local hardware store if you can’t find yours) or a flat-blade screwdriver.
At the top of the radiator at one end there will be a valve. You can attach the radiator key to the square bit in the centre or put the end of the screwdriver into the groove.
Hold the key or screwdriver with a cloth, and have another cloth ready to catch any drips, then slowly turn the radiator key or screwdriver anti-clockwise – if gas is escaping you’ll hear a hissing sound.
Once there is no more gas, liquid will come out and the valve will need to be closed quickly. With the more modern screwdriver operated escape valve, liquid is likely to emerge as a jet rather than a dribble.
Step 4: Check the pressure
Check the pressure by having a look at the gauge on your boiler. If the pressure is too low, you’ll need to ‘top up’. You can do this using the lever or tap on your boiler, known as the filling loop, and following the directions from your boiler manufacturer.
Afterwards, you may want to run another ‘hot test’ to check that your efforts have been successful. Simply turn your heating on, wait for all the radiators to heat up and check for any cool spots.