Why, you may wonder, do you need to bleed a radiator? Properties fitted with gas fired central heating have water-filled radiators which sometimes accumulate air bubbles inside. This stops the water from being pumped around the system properly, leaving radiators lukewarm except at the bottom, and you feeling the chill.
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To fix this you need to release the air with a radiator key. This is a short, sturdy key with big loops at the top forming an easy-to-turn handle and a square-shaped indentation at the other end. If you don’t have one at home, they are inexpensive to buy from a DIY shop.
To avoid burning yourself, only bleed a radiator when the heating is turned off. Check the top of the radiator to see which end has a little square piece sticking out – this is the air valve to which you fit the key. Hold a cloth or some kitchen roll underneath the valve to catch any drips, then turn the key slowly anti-clockwise. You should hear a hissing sound as the air releases. When all the air has gone, water will start to drip or splutter out of the valve. At that point, turn the key clockwise to tighten the valve.
It’s worth bleeding all the radiators to make your system work at its optimum efficiency. However, if this doesn’t solve the problem, or you are having to do this more than once every few months, you may need to call in a plumber.