Do cracked heat exchangers emit carbon monoxide?
A small crack or leak in your heat exchanger will not emit carbon monoxide. A large one will. If there is a crack safely check it out, but I would just go and get a new one regardless. It stinks but it really is not worth the risk in my book.
Usually the small cracks that are found in heat exchangers do not emit carbon monoxide. Large holes or openings, however, can produce carbon monoxide. A cracked heat exchanger is a sign of poor operation and is a defect that that needs to be repaired before it becomes dangerous. If the furnace is emitting minimal levels of carbon monoxide into the area, the equipment is safe to operate.
