Drained pressure from the system. Cut out and removed old purge station and male adaptor. Installed new purge station with isolation valve. Replaced circulator gaskets by the boiler. Filled system back up with water. Attempted to purge the air but found the autofeed was not allowing enough water though to force all the air out. After getting customer authorization we installed a new autofeed with backflow preventer. When attempting to remove the old autofeed the solder joint at the T snapped. Cut out and removed old 1-1/4 T and installed a new T with a 1/2 inch ball valve. Filled system back up with water and purged air out of the system. Started and tested the system. Had hot water coming back on all returns. When leaving boiler pressure was at 20 psi