Get a 5 gallon bucket fill it with water stick the end of a garden hose in it then connect the other end of hose to the drain valve on the boiler piping, turn on valve and keep end of hose submerged under water in bucket until no air bubbles are present, shut off drain valve and all air should be eliminated. An old timer showed me this trick after I changed a circulating pump and got air in the system with no bleeders and I tried for hours to get the air out, he came by and within 10 minutes he had it fixed, needless to say I felt like a dummy but il never forget it and have used it many times now. Hope this helps.
Thanks, I actually thought of this on my own while I was there, believe it or not. I don't think it made the process faster but it made it easier to see when the bubbles have gone.
America; first we fight for our freedom,
then we make laws to take it away.