So, I have had this home and heating system for 8 years. In the beginning i just would use my key and bleed the radiators before i would start it each year. ... HOWEVER 2 years ago a radiator cracked and most or all the water ran out onto the floor before i could get it fixed. (( JB Weld did the trick )) .. ANYWAY, last year they had issues - cold at the top - some very cold etc but still had water. This year I went to bleed them and nothing came out most of them but air .. the downstairs ones had water - So i went to the system and couldn't find out how to add water. It seems it is supposed to add it by itself but isn't .. so i kept pulling a valve that sounded like it added water and NOW there is no water coming out any of them and some are sucking air in. Emptied the tank above the system and did not help. No pressure ... No water ... and sucking in. ... PLEASE HELP !! 
