In a pinch, is it possible to use diesel fuel to fire a boiler that normally runs on no. 2 heating oil?
Three weeks from now, I'll be replacing my oil-fired boiler with a modern, environmentally friendly (er, friendlier) propane unit. Since the clock is ticking on my old, oil-fired boiler, I've allowed the heating oil in my tank to run down to an unthinkably low level. I'm not sure how much remains, due to a flaky meter, but it's in the range of a few gallons or so.
We're in the summer months, so my oil usage is small, but I nevertheless rely on it to heat my domestic hot water. There's a possibility I might run dry before the propane conversion begins. Unfortunately, the oil company sells heating oil in quantities of 50 gallons or more. Making a purchase now would leave me with 40 gallons or more of expensive oil--and an expensive disposal when I remove the oil tank several years from now.
Then, it struck me: why not buy a few gallons of diesel oil at the gas station, and use this instead? Ordinarily, I'd be hesitant to use an unrecommended fuel in my equipment, but the boiler will be junked after the propane unit's in. And according to Wikipedia, No. 2 heating oil
is similar in chemical composition to diesel fuel.
Is this stopgap solution a workable one? What would be the consequences of using diesel for the boiler, in terms of efficiency, fumes (if any), and keeping the boiler running for a scant three weeks? Has anybody tried this approach?