I just had a 75000 BTU Comformaker forced-air natural gas furnance installed. Works fine, great heat, but the noise is unbearable, I hate it. It's not the burners that are the problem, it seems to be the combustion fan. When the combustion fan kicks on (not the blower fan) the vibrations can be felt in the entire house, plus it sounds like a small lawn mower in my basement is running......what can be done???
check and see if the unit has more than one or two speed. it may be set in the high speed, or may look to see if all the shipping packing was removed. also, look at all the piping,connections and etc that there are no vibrations coming from them rather than the unit itself. if not, I would call the installer back, and if all is satisfactory instillation, i would call techinical services of the producer of the furnace. there could be a recall or working disorder with this model of furnace. I am sure a company this large will take care of such a minor problem for the homeowner.