heatslave12 14 spewing blck smke & smels, tnk ws empt, jst fild nev B4 smok?

My heatslave 12 14 is spewing black smoke and smells like paraffin, the entire house filled with smoke but from back yard vent. The oil tank ran dry and I had it filled, since filling the smoke has started. I never realised the oil tank was empty and tried to fire the unit 3 times, but the lock out light appeared. Please help this is urgent as our animals were all smoked out as this took place whilst at work. Could not see the other side of the room