Abstract: An atomizer injects fuel oil into one end of a heated tube. As the atomized fuel travels down the tube, it is vaporized. A nozzle at the other end of the tube assures that pressure is built up in the tube so that fuel oil vapor is applied as a steady continuous stream from the nozzle directly into a combustion chamber where it is mixed with ambient air and burned. Ambient air is drawn into the combustion chamber through a vent and a blower is not used. A secondary tube is in communication with the main tube through a bore in the side wall of the main heating tube near the outlet nozzle. A screen at the outlet nozzle prevents particles from clogging the nozzle. These particles fall into the secondary tube to be collected in a sump at the end of the secondary tube. Electric current is passed through the walls of the main heating tube and the secondary tube to generate heat to vaporize the fuel and to provide a temperature gradient along the main heating tube such that a maximum temperature of above 400.degree.