METHOD FOR CHECKING A GAS MIXTURE SENSOR AND IONIZATION SENSOR IN A FUEL-GAS-POWERED HEATING DEVICE

The invention relates to a method for checking a gas mixture sensor and ionization sensor with respect to their fault-free operation in a fuel-gas-powered heating device, wherein a gas mixture is produced by providing a quantity of gas via a first actuator (4, 107) and a quantity of fuel gas via a second actuator (3, 102) and mixing same, wherein the gas mixture sensor is positioned in the gas mixture for detecting a material property of the gas mixture (9, 105) and continuously transmits a sensor signal, which is dependent on the relevant gas mixture, to a control device (11, 100), wherein a flame signal is detected at a burner (109) of the heating device (200) via the ionization sensor, and an ionization signal is determined therefrom and transmitted to the control device (11, 100), wherein a corresponding ionization signal from the ionization sensor is assigned to the relevant sensor signal from the gas mixture sensor, and, for checking the gas mixture sensor and the ionization sensor, the gas quantity or the fuel gas quantity is temporarily changed in a predefined manipulated variable of the first or second actuator such that the gas mixture changes, and at the same time the resulting change in the sensor signal from the gas mixture sensor and in the ionization signal from the ionization sensor are measured and compared with one another.