Abstract: A pulse combustion space heater and burner are disclosed. The heater has an exterior cabinet enclosing an interior housing having the burner mounted therein. The burner includes a plurality of generally flat elements which cooperate with the interior housing to provide a tortuous path for air circulated through the chamber during heat transfer. A labyrinthine air flow passageway lined with sound attenuating material is provided immediately upstream of the heater air discharge. The burner tailpipe comprises a weldment of two identical sheet metal pieces which cooperatively define a tailpipe conduit. A fuel gas inlet orifice is mounted in the wall of the mixer head to effect both regulation of the average flow rate and injection of the fuel to enhance its mixture with the air.