Abstract: A heater system for a diesel fuel filter comprises a housing, a self-regulating electrical resistance heater element of positive temperature coefficient of resistivity arranged in heat-transfer relation to thermally conducting components to form a heater means, the heater means being mounted within the housing so that diesel fuel passes directly over and around the various thermally conducting components of the heater means to elevate the temperature of the fuel as it passes to the filter to deter clogging of the filter by paraffin or other fuel components which may solidify in the fuel at lower temperatures, and electrically conducting means which extend from the housing in sealed relation to the housing for electrically connecting the heater means to a source of electrical power.

Abstract: A fuel filter system for a diesel engine has filter means mounted in a housing so that diesel fuel flows through the filter as it passes to the engine and has self-regulating electrical resistance heater means mounted in the housing so that, particularly when the engine is started at low ambient temperatures, the fuel flows directly over the contacts, terminals and heater elements of the heater means for elevating the temperature of the fuel as it passes through the filter without risk of over heating the fuel, thereby to safely deter clogging of the filter by paraffin or other fuel components which may solidify in the fuel at relatively low engine starting temperatures.