While having my chimney cleaned yesterday the sweeper pointed out some holes and cracks between the two flues (fireplace and oil furnace). He said this is a safety issue as carbon monoxide from the furnace could vent into the house through the fireplace. He suggested installing a stainless steel liner and venting the oil furnace through it. Total parts and labor will be approx $1700.
I don't have a problem spending the money but since I use the fireplace infrequently, can I have the oil furnace vent directly out of the house through a new pipe? I believe this is how houses without chimneys vent. Are there any risks or issues with this approach? Is it more cost effective? Are there other options I could explore?