The radiators will not produce the same quality heat if there is air trapped inside the heating system. Usually air gets trapped into the system when it is topped with water. To solve this problem you need to know how to bleed a central heating system.
1. Locate the switch or valve that controls the central heating system and switch it off. If you can’t find it look on the unit’s manual for instructions.
2. Radiators should have a bleed valve located at the bottom and looking like knurled release handle in which case no additional tools are needed to bleed the system.
3. Prepare the area by wrapping the bleed valve in an absorbent cloth in case water dribbles when you turn the valve.
4. Open the bleeder valve by turning the handle counter-clockwise. If you hear a hiss of air while opening the valve gently it is a sign that the air is slowly getting out of the system.
5. When the air is completely out, water will start bleeding, meaning it’s time to close the valve.
