badflash you have to keep me posted on your fuel set up, i'm going to be looking at propane for my back up simply because if it's a back up it will be sitting. propane doesn't gell or sour like gas or diesel so i would rather look in that direction, plus i have a 1000 gal a 250 gal and a couple smaller tanks about so if i go with the multi fuel,wood coal or pellets primary on a boiler i would want the propane to back it up. i also have a 5k propane kohler generator.