The verb is bleed. Bled is the past tense of bleed. The present tense of bleed is present simple -- bleed or bleeds present continuous -- am bleeding, is bleeding, are bleeding present perfect -- have bled, has bled present perfect continuous -- have been bleeding, has been bleeding
There could be trapped air in the system. Turn off all rads on your ground and third floor and if needed one of the two on your second floor . This should force any trapped air into the rad and you can bleed it off. Good luck!!