Abstract: A fryer unit includes a fryer vat defining a volume for receiving oil to be heated for cooking. A heating system is provided for heating oil in the volume. The heating system includes at least one gaseous fuel burner and at least one heat exchange tube, the heat exchange tube passing through the volume such that an external surface of the heat exchange tube will be in contact with oil in the volume. The heat exchange tube defines an internal passage through which heated combustion gases of the gaseous fuel burner can pass, and a baffle is positioned within the internal passage for enhancing heat transfer from the combustion gases to the external surface of the heat exchange tube.