Radiator not heating, at all.

[PlumberInTheMaking]

Hi - So I did the basic stuff. I've bled the rad and nothing. We had decorators in a while ago and as the weather was nice we haven't needed the heating on, till now. Then when we tried to put the heating on, all but the one in my room works.

I noticed that on the bottom was a plastic cap with a screw in. I unscrewed the cap and found a | shape (Where the screw goes into) any advice? Bed is cold!!

 

[PrenticeBoyofDerry]

The cap you have removed is from the lockshield valve. This is used to balance the system, for you to have heating the valve must be open to some degree.
On the opposite of the radiator, it is possible you have thermostatic radiator valves (TRV) , these can seize or jam if turned off over a period of time.
This could be the reason that you have cold radiators. The valve pin wants releasing.
helpful vid

 

[PlumberInTheMaking]

The cap you have removed is from the lockshield valve. This is used to balance the system, for you to have heating the valve must be open to some degree.
On the opposite of the radiator, it is possible you have thermostatic radiator valves (TRV) , these can seize or jam if turned off over a period of time.
This could be the reason that you have cold radiators. The valve pin wants releasing.
helpful vid

Hi. This is the setup, so it's not your everyday one.
//www.diynot.com/network/PlumberInTheMaking/albums/18026/67749

 

[ianmcd]

you have two lockshield valves make sure both are open by turning then anti-clockwise

 

[PlumberInTheMaking]

you have two lockshield valves make sure both are open by turning then anti-clockwise

Feels like if I do it will break? :O

 

[skenk]

They do stick, and can snap off. Suspect you need a 'plumber in the flesh' if you don't want to risk causing more problems. Valve on the left looks like it could be a regular valve, not a lockshield? If it's not a lockshield using the plastic handle to loosen the valve should be fairly risk free as the plastic threads/grooves will go before you cause real damage. Sometimes tightening slightly before unscrewing helps. A little WD40 might help.