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?

Personally, I would consult the furnace manufacturer's documentation and the company that supplies your heating oil. There may be corrosion inhibitors, anti-gum or anti-separation compounds, etc. in the heating oil that you don't want to dilute too much.

Alternatively, advertise and sell it. Somebody will grab it at a discount for temporary heat (in a greenhouse, for example).

BTW, I recall reading about low odour kero somewhere. Probably less sulfur and other odds-and-ends. Might be more pleasant than the old-school stuff.

+1

Many years ago I was told that there is nozzle inside the furnace that turns the liquid oil into a fine mist that will burn as quickly and completely as possible to produce as much heat as possible (thus being most efficient) and producing the least soot and other undesirable products like carbon monoxide(which result from incomplete burning).

Reducing the soot also helps maintain the system and reduces the chance of a fire. (think of something like a chimney fire, but in the furnace.)Carbon monoxide dangers are obvious.

That nozzle is specifically designed to work with a particular oil of given characteristics.

If you blend the oil with the Kerosene, the resulting mixture will have different characteristics and may not burn correctly or efficiently in your furnace and cause any or all of the mentioned problems.

I don't think it is worth the risk.