radiator is warm at the top and cold at the bottom?

Circulator pump is either inoperative or set wrong.
Set circulator around 180 degrees and the limit to 212 degrees
Water boils at 212 and should get system hot enough to force out any remaining air pockets. Continue to bleed if necessary until radiators are hot top to bottom. Re-titghten all bleeder valves and check air purge valve for damage.

Terry T.
November 2005