Thanks for the added info. Our filter is right near the floor, actually sits on the floor in front of the one tank. I don't have a spare cartridge or anything so don't have any way to bleed the lines and know nothing about priming the pump so I think I've taken this as far as I can and have called the oil company. They're on a call now but will call me back and let me know when they can get up here. I just told them it'll have to be in the afternoon if it's today because of my conference call schedules for work and I want to stand there and explain everything I've already done and see what they do.
thanks for all the help and I'll post back once I get word on what's what.