Dead radiator

[Jim]

In house I have bought it has a loft conversion. The feed and expansion tank and the radiator are at this level. The level of the water in the f/e tank is such that it would be only three inches from the bottom of the radiator. The radiator is 16" high (and has a temperature control valve).Therefore I assume the top 13inches would have no water.
The previous owners say it used to work but I can neither get air or water or heat from it.
When I found the bleed valve at the back of the radiator it had one of those white plastic screw covers over it - why I cant guess.I removed it and turned the valve to no avail.
Is it possible that despite the levels described that someone found a way of filling the radiator originally which allowed heated water to circulate.
Can anyone suggest what the problem is and how to solve it.
JJ

 

[MANDATE]

The level of water in your radiator cannot be higher than the level in the tank.
you need to raise the water level by raising the tank as high as possible
and lower the radiator if possible.
You could experiment bymoving your radiator to a near horizontal position instead of vertical when the 3in of water will fill it and you can also bleed off the air

 

[Jim]

Thanks - Will have a go at that
Jim