A radiant heater includes a generally U-shaped radiative heating element having a first straight section, a second straight section, and an interconnecting U-shaped section. The non-connected end of the first straight section is arranged for communication with a burner and the non-connected end of the second straight section is arranged for communication with an extractor for extracting combustion gases from the tube. A redirecting element including opposed helical vanes, each executing a 180° turn about a central, common tube, is arranged within the first straight section so as to redirect, in use, at least a portion of the combusted gases flowing within the upper half of the tube towards the lower half, and gases flowing in the lower half towards the upper half.