I too am a Licensed General Contractor in Michigan, and I have used diesel fuel in the dead of winter to keep my old oil furnace running until I can et a delivery. The home heating oil you get from the company in summer is plain old diesel. In the winter months, they provide “Winter mix” which is 50% #1 and 50% #2 heating oil, and is necessary to keep the cold temperatures from causing the oil to gel. In a pinch diesel will work, but remember that it is $4+ a gallon and you’ll need several gallons. If you think you are going to run out before morning, add the diesel before the tank is pushing the dregs, water, and sludge from the bottom of your tank into your furnace. When I had an oil home improvement furnace, I made a dipstick out or a long strip of molding. I marked level of the fuel on the stick ( with a sharpie marker ) after the delivery, and then beautiful gardens every few days as the fuel oil was used. Later, I could put my home made dipstick in the tank outdoor ideas at any time and know how many days I had left. I could call the company during the week, and a few days early so that I never ran out, and so that home improvement they didn’t have to make an expensive special delivery on holidays and weekends.
Mark: it is perfectly safe because the diesel fuel and the home heating oil are exactly the same thing.