German Furnace Share definition Flag A self inflicted Dutch Oven. Farting under your covers and pulling them over your own head to enjoy your gastro aroma! Dude, I love smelling my own ass so much I am a frequent occupant of the German Furnace. German Furnace by AD218 August 26, 2008 0 0 Get merch Get the German Furnace mug. Buy Now — $32.95 See more merch