Greenstar 20Si/30Si Worchester Boiler?

I removed one radiator without following any procedure water all over the place and when i put the radiator back the boiler pressure was at zero. Their is no plastic key for this model but has a filling loop fitted with two valves.
On opening these the gauge rises very slowly to 1 bar but when closing the valves the pressure drops to zero with water coming out of the overflow pipe outside.
Tried bleeding radiators but no air or water coming out.