Oil-filled heaters are sometimes called oil radiators because they resemble old-fashioned steam radiators. Instead of using steam, however, these modern space heaters are filled with oil. They run on electricity and can be rolled from room to room.
Oil-filled heaters use a radiant heating method. As the oil sealed inside a row of "fins" becomes hot, it releases (radiates) that warmth into the air. Because there is no fan to blow the heated air through a room, the increase in room temperature is steady but slow.
Most oil-filled heater units have three heating levels. On low, a typical unit will use 600 watts. On high, the wattage use will be 1,500. The medium setting will consume 900 watts. Oil-filled stoves are available with thermostats to maintain specific temperature settings. Some offer a special antifreeze setting, as well.
During operation, the fins can become quite hot, but the edge of each fin doesn't get hot enough to burn fingers or to start a fire if the unit is knocked over. Nevertheless, many models offer both tip-over and overheat protection.