Did you just wire it in to the power switch for the furnace? I plan on doing this as well if needed, and maybe even prepping it with a transfer switch of its own.I have been doing the same thing! I figured I would use the 7.2 every now and then, but this sold it for me. Luckily the blower on the furnace only uses 400w. Been running for days with no issues. I only wish I could turn the screen on the dash off.