You’re reading this column so you probably know this, but I didn’t until I wrote this story, prodded by the cold snap and people running out of heating oil (which heats about half the residences in New Hampshire):
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.
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.