Bleeding radiators

[Plumbingrp]

Hi
one of my radiaters clearly has air in it but when I open the valve nothing comes out. The valve is the same as the one below, do I need to loosen the nut as well please or any other ideas or help would be great. Thank you

 

[exedon2]

Chances are its blocked turn off both valves on rad
Use you key to take out air valve use a needle or similar to clear any muck replace valve turn on rad valves see if its cleared.

 

[Plumbingrp]

Chances are its blocked turn off both valves on rad
Use you key to take out air valve use a needle or similar to clear any muck replace valve turn on rad valves see if its cleared.

Thanks that’s great