Method for driving a modulating valve regulating the flow rate of gas (Qgas) towards a burner of a condensation boiler having high power modulation, the boiler of the type including an air-gas mixing system comprising a fan and a conduit extending between an air-gas mixing zone and the burner, the valve including a valve seat associated with a corresponding closure member, and an electrical operating means capable of controlling the displacement of said closure member relative to the valve seat so as to regulate by modulation the flow rate of gas (Qgas) delivered, the operating means being of the type comprising at least one electromagnet, the valve being designed so as to operate with a predetermined characteristic curve, the flow rate (Qgas) delivered being proportionally related to the strength of a first current signal (Imod) sent to said electromagnet such that the flow rate (Qgas) can be modulated, using said characteristic of proportionality, within a range of modulation between a maximum flow rate (Qgas_max) and a minimum flow rate (Qgas_min), said minimum flow rate corresponding to a value (ImodO) of said first current signal, below which the valve is not capable of delivering gas in a controlled manner, characterised in that, to deliver controlled flow rates (Qgas) of gas that are below said minimum flow rate (Qgas_min), thereby extending the range of modulation into minimum deliverable flow rate values, provision is made to: - drive the electromagnet of the operating means with a second PWM voltage signal capable of generating a corresponding second PWM current signal (Imod') in said electromagnet, so as to move said closure member according to said second signal (Imod'), in that the frequency (fp) of said second signal (Imod') is chosen from a value higher than the natural response frequency (fm) of the mixing system and a value lower than the natural response frequency (fv) of the valve, and in that, the terms first (Ta) and second (Tb) time interval being given to the successive durations of the high signal and the low signal, respectively, the sum of which is equal to the period of said second signal, with a duty cycle (dc) equal to the relationship Ta/T, the strength of said second current signal (Imod') is modulated: - by amplitude modulation of the second signal (Imod'), leaving the duty cycle (dc) constant, i.e., Ta/T=constant, so as to vary the flow rate (Qgas) accordingly, or - by modulation of the duty cycle (dc) in the period, keeping a preset amplitude of the second signal (Imod') constant relative to said first time interval (Ta), so as to vary the flow rate (Qgas) delivered accordingly. - drive the electromagnet of the operating means with a second PWM voltage signal capable of generating a corresponding second PWM current signal (Imod') in said electromagnet, so as to move said closure member according to said second signal (Imod'), in that the frequency (fp) of said second signal (Imod') is chosen from a value higher than the natural response frequency (fm) of the mixing system and a value lower than the natural response frequency (fv) of the valve, and in that, the terms first (Ta) and second (Tb) time interval being given to the successive durations of the high signal and the low signal, respectively, the sum of which is equal to the period of said second signal, with a duty cycle (dc) equal to the relationship Ta/T, the strength of said second current signal (Imod') is modulated: - by amplitude modulation of the second signal (Imod'), leaving the duty cycle (dc) constant, i.e., Ta/T=constant, so as to vary the flow rate (Qgas) accordingly, or - by modulation of the duty cycle (dc) in the period, keeping a preset amplitude of the second signal (Imod') constant relative to said first time interval (Ta), so as to vary the flow rate (Qgas) delivered accordingly.