A machine for coffee or other infusions in boiling water, comprising: a heater, comprising a tube predisposed for being heated for the purpose of increasing the temperature of a flow of water, continuous or discontinuous, between an inlet and an outlet; heating means predisposed for utilising an electric current for the purpose of heating the tube; comprising: at least one temperature sensor structured in such a manner as to be substantially at the same temperature as the tube and to vary in resistance based on its own temperature; a controller, predisposed for commanding the delivery of an electric heating current to the heating means and delivery of an electric measuring current to the temperature sensor; a processing block, predisposed for measuring the voltage present at the terminals of the temperature sensor, when the electric measuring current is passing through it, and for comparing the measured voltage with a known reference voltage, generating an error signal; the controller being predisposed for commanding the delivery of said electric current to the heating means, said electric current being proportional to the error signal received; characterised in that: the heating means and the temperature sensor comprise the tube, made of metal material and predisposed for having an electric current pass therein between two ends thereof. a heater, comprising a tube predisposed for being heated for the purpose of increasing the temperature of a flow of water, continuous or discontinuous, between an inlet and an outlet; heating means predisposed for utilising an electric current for the purpose of heating the tube; comprising: at least one temperature sensor structured in such a manner as to be substantially at the same temperature as the tube and to vary in resistance based on its own temperature; a controller, predisposed for commanding the delivery of an electric heating current to the heating means and delivery of an electric measuring current to the temperature sensor; a processing block, predisposed for measuring the voltage present at the terminals of the temperature sensor, when the electric measuring current is passing through it, and for comparing the measured voltage with a known reference voltage, generating an error signal; the controller being predisposed for commanding the delivery of said electric current to the heating means, said electric current being proportional to the error signal received; characterised in that: the heating means and the temperature sensor comprise the tube, made of metal material and predisposed for having an electric current pass therein between two ends thereof. at least one temperature sensor structured in such a manner as to be substantially at the same temperature as the tube and to vary in resistance based on its own temperature; a controller, predisposed for commanding the delivery of an electric heating current to the heating means and delivery of an electric measuring current to the temperature sensor; a processing block, predisposed for measuring the voltage present at the terminals of the temperature sensor, when the electric measuring current is passing through it, and for comparing the measured voltage with a known reference voltage, generating an error signal; the controller being predisposed for commanding the delivery of said electric current to the heating means, said electric current being proportional to the error signal received; characterised in that: the heating means and the temperature sensor comprise the tube, made of metal material and predisposed for having an electric current pass therein between two ends thereof.