cool rad upstairs pressurised system

[shotbird]

i have a a combi system (sealed) radiators upstairs are cold at the top and hot on the bottom tryed to bleed them a little air came out but no water and the air has stopped comming out still no wateri have shut down all the hot ones bar one cool one but the water still does not fill tha rad any ideas whats wrong.

 

[Bahco]

Check the reference section above.

 

[bab]

Does sound like u r out of pressure. whats the gauge say on ya boiler. should be around 1 when cold & system is full.