Good points. I wonder how the leakage from the relatively large amount of furnace gas compares to the leakage from the relatively small amount of stove gas. For

Good points. I wonder how the leakage from the relatively large amount of furnace gas compares to the leakage from the relatively small amount of stove gas. For example, if the furnace uses 10x cubic feet of gas and leaks 50% less per cubic foot than the stove, the furnace will leak 5x more cubic feet than the stove. (Completely made up numbers.) Then the next question is, how does the furnace leak in the basement affect the air quality where people typically breathe?