If the top of your radiator is cold and the bottom is hot, it may need to be bled. You will need a key for this, which is normally supplied with your radiator.

1. Make sure your heating is switched off. If your radiator is part of a sealed central heating system, it will be necessary to lessen the overall pressure of the whole system. Have a look at your manual.
2. Find the valve. It is found near the top and will be a small protrusion.
3. Insert the bleed key into the bleed valve. Have a bowl or empty ice cream tub underneath the valve or on the floor to catch any water which may escape.
4. Carefully turn it, slowly, anticlockwise by around a quarter of a turn. You will hear air hissing out of the radiator- this is normal!
5. Turn it back to its original position once you hear a gurgling or if any water drips out. The aim is to open the valve enough to let air escape but not enough to allow all the water to come out.
6. Switch your heating back on.
7. Check for leaks, you don't want to ruin your carpet. IF there's any water still dripping out of the bleed valve, you may need to turn it again gently clockwise to tighten it.

If in doubt contact plumber of gas heating specialist.