Vaishali industries Heavy Industril Fuel Oil/Low Industril Fuel Oil Product for Heating oil, also called fuel oil, is used in boilers and furnaces for heating homes and buildings, for industrial heating, and for producing electricity in power plants.fuel oil, also called furnace oil, fuel consisting mainly of residues from crude-oil distillation. It is used primarily for steam boilers in power plants, aboard ships, and in industrial plants. Commercial fuel oils usually are blended with other petroleum fractions to produce the desired viscosity and flash point.