Abstract: A fuel preheater for liquid fuel having a multi-pass heat exchanger for said fuel, heated by an electrical resistance heater provided with a sensor adjacent the device designed to burn the fuel, the sensor controlling the flow of electrical current to said heater. The heat exchanger is preferably made from extruded stock and a material having good heat conductivity. If the device burning the fuel is a water cooled device, a separate heat exchanger using such heated water may be placed in series with the preheater in order to augment it.