Electrical liquid heating device for a motor vehicle, said heating device comprising at least one module for heating said liquid, said at least one heating module comprising: - an approximately cylindrical enclosure having at least one means for heating said liquid and delimiting a circuit for guiding the liquid to be heated, and - a control means of said at least one heating means, positioned in continuation of the longitudinal axis of said cylindrical enclosure, characterized in that it has at least one liquid inlet canal and at least one liquid outlet canal communicating with said circuit for guiding said liquid, said inlet canal and outlet canal leading into the guiding circuit, and the inlet canal and outlet canal are provided in said device in a manner approximately perpendicular to the longitudinal axis of said cylindrical enclosure, said at least one heating module is accommodated in an associated housing of the heating device, the heating module has an approximately cylindrical overall shape and the heating module comprises a central core arranged inside said cylindrical enclosure which surrounds the central core, the circuit for guiding said liquid being defined between said core and said cylindrical enclosure, the enclosure comprises heating elements controlled by the control means for heating the liquid by heat exchange between the enclosure and the liquid circulating in the guiding circuit, the control means being arranged at a longitudinal end of the cylindrical enclosure carrying the heating means, the control means is positioned in the region of the end of the housing of the heating device accommodating the heating module, the heating device thus having a support for the control means positioned so as to close this housing accommodating the heating module. - an approximately cylindrical enclosure having at least one means for heating said liquid and delimiting a circuit for guiding the liquid to be heated, and - a control means of said at least one heating means, positioned in continuation of the longitudinal axis of said cylindrical enclosure, characterized in that it has at least one liquid inlet canal and at least one liquid outlet canal communicating with said circuit for guiding said liquid, said inlet canal and outlet canal leading into the guiding circuit, and the inlet canal and outlet canal are provided in said device in a manner approximately perpendicular to the longitudinal axis of said cylindrical enclosure, said at least one heating module is accommodated in an associated housing of the heating device, the heating module has an approximately cylindrical overall shape and the heating module comprises a central core arranged inside said cylindrical enclosure which surrounds the central core, the circuit for guiding said liquid being defined between said core and said cylindrical enclosure, the enclosure comprises heating elements controlled by the control means for heating the liquid by heat exchange between the enclosure and the liquid circulating in the guiding circuit, the control means being arranged at a longitudinal end of the cylindrical enclosure carrying the heating means, the control means is positioned in the region of the end of the housing of the heating device accommodating the heating module, the heating device thus having a support for the control means positioned so as to close this housing accommodating the heating module.