so most of the folks in my neighborhood (and i in the past) have conventional wood stoves and all day and night i see white and bluish white smoke rising out of their chimneys and that awesome "campfire" wood smell permeates the area. everytime i add wood to my harman sf-160 boiler, i get a nasty black smoke and smell like burning tar--almost smells like burning fuel oil. the black smoke and scent lasts for less than five minutes and is followed by some very light smoke or just heat waves coming out of the flu and the smell dissipates. it doesnt matter what species of wood, how much airt intake i have, or how thick of a bed of embers i have---same nasty smoke and nasty smell. it does it when i burn my 2.5 year old wood or my 1 yr. old wood. i had the chimney swept about six weeks ago and got a coffee can of fine dark gray soot, no creosote and the inside of my firebox has very little buildup and most of it is a very light gray ash. why does my boiler produce that nasty black smoke and smell when i add wood versus what i see coming out of my neighbors' stacks?