A burner includes an atomizing chamber, a flame tube in front of the atomizing chamber adapted to direct combusting fuel introduced by the atomizing chamber along an interior of the flame tube, and a controller. The controller is programmed to independently control rate of fuel flow to the atomizing chamber, rate of atomizing air flow to the atomizing chamber, and rate of combustion air to the flame tub. The controller is also programmed to perform operations including regulating, based on output of a gas sensor, at least the rate of combustion air to the flame tube to substantially maintain a first predetermined amount of excess air in the flame tube.