Steven your blow off value within the boiler is normal set at 3 bar which means that the blow off value should off kicked in to let the water out ( Safety device) the best way for you to reduce the presure is get a small dish,place it under the radiator vent side and open the vent to allow water to escape . This will reduce the water presure. Should be set 1.2 bar or to instructions of boiler. Hope this helps. Oh get the blow off value checked this may still let water out if not reset
Chris Plumbing @ Heating NI, January 2009
