This paper presents the results of a controlled acoustic excitation of a liquid fueled nonpremixed flame as a means of nitric oxide reduction. The experimental burner is a domestic hot-water heater provided by Viessmann. An actuator is located on the air duct and comprises two perforated plates. By changing the speed of rotation of the rotor it is possible to achieve a single frequency excitation of the burner cavity. The industrial version of the burner already features low NOx exhaust levels (82 ppm at 0% O-2) and satisfies the current European regulations concerning pollutant emissions. Its operating point corresponds to an equivalence ratio of 0.82. It is shown that for a broad range of frequencies (100 Hz to 700 Hz) the overall nitric oxide emissions are reduced up to 15%. Radical imaging of the excited dames shows strong effects of the excitation on the dame geometry, especially on the flame length, and gives guidelines to a new, more effective, NOx emission control using acoustic excitation.