I didnt see where you answered my question yet. How are the loops tied together now? Reverse return, in series ( from one loops exit into the second loops supply), or parrellel (supply and supply are together, and returns are together)???? What is it he purging it with? A flush cart i hope. I understamd they are seperated into 2 fields. 1 field does upstairs, and other field does down stairs, is this correct? If so, does either of the floors out perform each other?