Running out of heating oil? Using diesel as a substitute can tide you over 

Homeowners who run out of heating oil and can’t wait days for a refill have an option: diesel fuel.

Diesel, as sold at many gas stations, is an acceptable replacement for home heating oil in virtually all furnaces. Both diesel and heating oil No. 2 are midlevel or midweight distillations of petroleum that produce roughly the same amount of heat and can be burned by the same systems.

Gasoline, on the other hand, is a lightweight distillation that cannot be used as a substitute for heating oil. Do not put ordinary gasoline in your oil tank – it will damage your furnace and cause other problems.

If you’re on the verge of running out of heating oil, or have run out, pouring diesel fuel into the tank can hold you over until a delivery is made. Diesel was selling for $2.45 a gallon on average in New Hampshire as of Tuesday, according to price-tracking website GasBuddy.com.

It’s recommended that you turn off your furnace before pouring the diesel into your heating oil tank, then wait 10 minutes or so before turning the furnace back on. This will allow any sediment that was stirred up by diesel being poured into the tank to settle, making it less likely to clog the system.

Running on diesel for too many days is not a good idea, however, as it can eventually interfere with the operation of the furnace.

Kerosene is another acceptable alternative to home heating oil of the type known as No. 2, a designation that indicates its weight and grade. Almost all home heating oil is No. 2; if you happen to burn a different weight of oil, diesel may not be an acceptable substitute.

Note that it is not a good idea to make the diesel-oil substitution in the other direction: That is, home heating oil is not a good replacement for diesel in vehicles because it lacks lubrication aspects that are important for engines to operate.