Have you ever referred to the fuel in your heating system as furnace oil? How about home heating oil or fuel oil? At first glance, these descriptive terms may seem interchangeable, but there are some subtle differences.
First, furnace oil or home heating oil applies only to the heating fuel your furnace uses to heat your home.
You can also call the heating oil that powers your furnace fuel oil, but be aware that this term is not limited to home heating oil. Fuel oil is a broader term because it refers to any petroleum product that can power a home heating system or an engine. For instance, diesel fuel is a good example of a fuel oil.
What these terms have in common is that all of these fuels are derived from crude oil during the refining process, which separates crude oil into different “fractions” while removing impurities.
The lighter fractions of crude oil eventually become propane, butane, and petrochemicals while heavier fractions are used to produce gasoline, kerosene, jet fuel, diesel fuel, and No. 2 home heating oil. Heavier fractions become No. 4 or No. 6 heating oils. This is used for commercial and industrial buildings, schools, and hospitals.
You either have an oil furnace or oil boiler in your home. A furnace uses air to heat your home, while boilers use water. Furnaces and boilers both use oil to generate heat, and it starts in the combustion chamber, where the oil is tuned into a flame by the oil burner.
The burner can be considered the engine of your heating oil system. When your house gets chilly, the thermostat will send a signal to tell the oil burner in the furnace or boiler to turn on. A fuel pump then starts to draw the oil from the tank and through fuel lines to reach the oil burner.
There is a device on the burner called the nozzle, which turns the oil into a very fine spray. This oil mist mixes with air and ignites in the combustion chamber, which gets very hot. This heat then gets moved around your home and comes out either through radiators or baseboards (if you have a boiler) or vents (if you have a furnace).
Read more about heating oil boilers and furnaces.