Oil burner went out at 2 AM. Rather than deal with it in depth at the time, I fired up a "garage" propane heater (inside the home). It puts out a relatively fierce amount of heat, about 15,000 BTUs. Don't shoot me, just guessing. I have a carbon monoxide detector, which I moved to the sleeping area, watching it nervously all night but it never registered above zero. Detector is a couple of years old. So what gives? Where did the CO go? Also have a gas stove and it never sets it off, either. Yes...it has fresh batteries.