While many types of fuel are capable of heating commercial and residential buildings, heating oil is among the most popular across the country. This heating oil, sometimes referred to as #2 heating oil, derives its popularity from its high calorific value, a fancy way of saying that it produces a lot of heat per unit. It is also easy to store in oil tanks, allowing customers to purchase cheap fuel during the warmer months and then save it until it is needed. However, when temperatures drop, your heating oil can freeze. Learn what you can do to prevent this as well as what you should do if you do find that your fuel oil has become frozen.