Abstract: A fuel control and preheating module for use with an oil-burning furnace including a fuel line providing a passageway section through which oil is routed from a reservoir to the furnace for burning includes an electrically-powered positive temperature coefficient (PTC) heating element mounted in heat transfer relationship with oil contained with the passageway section. During the operation of the PTC element, the PTC element heats the oil contained within the passageway section to a preselected temperature and maintains the oil contained within the passageway section at the preselected temperature. Also associated with the module is a movable diaphragm and shutoff plate which is responsive to the internal pressure changes in the air passageway of the furnace upon shutdown and start-up of the furnace to withdraw oil from and shut off delivery of oil to the nozzle upon furnace shutdown and to push oil toward the nozzle upon start-up of the furnace.