Control method for a rapid heating apparatus for liquids, characterized in that said control method comprises: - detecting, using a detection and control device, a proximity signal correlated to a flowmeter able to measure a flow of liquid in a rapid heating unit of the rapid heating apparatus, and provided with a turbine with a rotor, wherein said proximity signal is a signal generated by the cooperation of proximity between a sensor element and the turbine of said flowmeter; - analyzing a temporal development of the proximity wave form of the proximity signal; - defining a lower threshold and an upper threshold in the temporal development of said proximity wave form; - defining, in the temporal development of said proximity wave form, as a low peak a peak whose maximum is below the lower threshold and as a high peak a peak whose maximum is above the upper threshold, wherein defining the low peaks and the high peaks provides to detect the points of relative maximum of the proximity signal and to recognize, among said points of relative maximum, primary points of maximum as the relative maximums of the proximity signal each time said upper threshold is exceeded, associating them with said high peaks, and secondary points of maximum as the relative maximums of the proximity signal when this falls below said lower threshold, associating them with said low peaks.; - detecting and counting the number of high peaks and the number of low peaks inside a period, or a whole multiple of said period, of the temporal development of the proximity wave form of the proximity signal,; - if the number of low peaks in the period is greater, possibly by a defined margin of tolerance, than the number of high peaks, supplying an indication of malfunctioning or damage of the rotor of the turbine of the flowmeter. - detecting, using a detection and control device, a proximity signal correlated to a flowmeter able to measure a flow of liquid in a rapid heating unit of the rapid heating apparatus, and provided with a turbine with a rotor, wherein said proximity signal is a signal generated by the cooperation of proximity between a sensor element and the turbine of said flowmeter; - analyzing a temporal development of the proximity wave form of the proximity signal; - defining a lower threshold and an upper threshold in the temporal development of said proximity wave form; - defining, in the temporal development of said proximity wave form, as a low peak a peak whose maximum is below the lower threshold and as a high peak a peak whose maximum is above the upper threshold, wherein defining the low peaks and the high peaks provides to detect the points of relative maximum of the proximity signal and to recognize, among said points of relative maximum, primary points of maximum as the relative maximums of the proximity signal each time said upper threshold is exceeded, associating them with said high peaks, and secondary points of maximum as the relative maximums of the proximity signal when this falls below said lower threshold, associating them with said low peaks.; - detecting and counting the number of high peaks and the number of low peaks inside a period, or a whole multiple of said period, of the temporal development of the proximity wave form of the proximity signal,; - if the number of low peaks in the period is greater, possibly by a defined margin of tolerance, than the number of high peaks, supplying an indication of malfunctioning or damage of the rotor of the turbine of the flowmeter.