Everyone in Minnesota should be aware that the furnace, water heater, fireplace, wood stove, and other flame producing devices use large amounts of combustion air and this air must constantly be replaced. Warning signs .
Carbon monoxide is odorless and colorless, but there can be signs of problems.
The gas flame in the furnace or heater burns yellow instead of blue. In the case of an oil furnace or heater, black chimney smoke, soot accumulation, and popping, banging, rumbling, or delayed ignition. In the case of a natural gas furnace, excessive moisture on windows and walls, although this could be a symptom of other moisture problems and not necessarily of combustion air problems. In the case of wood burners, a smoking fire and improper drafting, even when the flue has warmed up. If you notice any of the above signs, call a professional heating contractor immediately and have your system checked.