I have a portable indoor kero heater which I haven't used in years because of all the junk it puts into the air. Because of several recent power failures, I've been thinking about some emergency kero. I know that kero has a shelf life, so I would want to rotate it. I also know that it has a lower boiling temp and is lighter in weight than #2 heating fuel.

My question: Rather than burn off or dump old kero, could I add small quantities (15 - 20 gallons) to my home heating oil tank?

Are there safety or furnace performance issues?