Abstract: In a process for operating a gas blower burner, a control circuit detects an ionization signal Ui derived from an ionization electrode, and it adjusts the gas-to-air ratio to a lambda set point >1, to which a set point Uis of the ionization signal corresponds. To guarantee low-emission combustion in different operating states, a range of control of the ionization signal Ui is set, whose upper limit value Uio is smaller than the maximum of the ionization signal Ui, and whose lower limit value Uiu is above the value that guarantees low-emission operation. A switch-off signal is generated for the burner if the ionization signal Ui leaves the permissible range of control RB for longer than a preset period of time.