Just think of your home heating system. The oil that is burned in your furnace is called fuel oil. It is a liquid that is normally kept in large storage tanks outside your home. When you turn on the system and start heating your house, the fuel oil is burned and turned into heat. The same is true for an oil fired heating system. The oil is burned in the furnace and turned into heat used to warm the house. With the same energy used, more oil will be burned andWhat is thermal oil? These are the common questions that most people ask. Thermal oils are made of different types of additives and base oils, which are mixed and processed in a specified temperature range. They are used in the transmission of power or heat in the form of steam, hot water, or oil.