Ours is the opposite. Heat pump and air system is main. When too cold for heat pump to run efficiently the oil burner and hot water baseboard kicks in. By then we usually have the woodstove going though. I need to get the flue pipe back together. Had water coming down the wall the other day. Due mostly to poor chimney design. It has a little weep drain in base that gets full of soot. Got it cleaned out and opened yesterday, but need to finish the job. It is cold again, so need to get that done...