Method for operating a gas burner appliance (10, 10'), by providing during an actual burner-on-phase of the gas burner appliance (10, 10') in request to an actual nominal heat demand a flow of a gas/air mixture to a burner chamber of the gas burner appliance (10, 10'), the gas/air mixture having a defined mixing ratio of gas and air needed for a regular combustion of the gas/air mixture within the burner chamber, wherein said gas/air mixture is provided by a mixing device of the gas burner appliance (10, 10') mixing an air flow with a gas flow, wherein the air flow or the flow of the gas/air mixture is provided by a fan of the gas burner appliance (10, 10') in such a way that a fan speed of the fan depends on the actual nominal heat demand of the gas burner appliance (10, 10'), wherein the fan speed range of the fan defines a modulation range of the gas burner appliance (10, 10'), wherein said defined mixing ratio of gas and air of the gas/air mixture is controlled by a controller using as input a signal provided by a sensor (13, 27) and providing as output a control variable for an electric or electronic gas flow modulator in order to keep the mixing ratio of gas and air of the gas/air mixture at the defined mixing ratio over the modulation range of the gas burner appliance (10, 10'), characterized in that if the actual nominal heat demand of the gas burner appliance (10, 10') is no longer present, the following steps are automatically executed in order to set-up the gas burner appliance (10, 10') for an upcoming burner start: decrease during the actual burner-on-phase the fan speed of the fan to a defined fan speed while keeping the mixing ratio of gas and air of the gas/air mixture at the defined mixing ratio thereby decreasing the opening position of the electric or electronic gas flow modulator, keep the electric or electronic gas flow modulator at said decreased opening position and terminate the actual burner-on-phase of the gas burner appliance (10, 10'). by providing during an actual burner-on-phase of the gas burner appliance (10, 10') in request to an actual nominal heat demand a flow of a gas/air mixture to a burner chamber of the gas burner appliance (10, 10'), the gas/air mixture having a defined mixing ratio of gas and air needed for a regular combustion of the gas/air mixture within the burner chamber, wherein said gas/air mixture is provided by a mixing device of the gas burner appliance (10, 10') mixing an air flow with a gas flow, wherein the air flow or the flow of the gas/air mixture is provided by a fan of the gas burner appliance (10, 10') in such a way that a fan speed of the fan depends on the actual nominal heat demand of the gas burner appliance (10, 10'), wherein the fan speed range of the fan defines a modulation range of the gas burner appliance (10, 10'), wherein said defined mixing ratio of gas and air of the gas/air mixture is controlled by a controller using as input a signal provided by a sensor (13, 27) and providing as output a control variable for an electric or electronic gas flow modulator in order to keep the mixing ratio of gas and air of the gas/air mixture at the defined mixing ratio over the modulation range of the gas burner appliance (10, 10'), characterized in that if the actual nominal heat demand of the gas burner appliance (10, 10') is no longer present, the following steps are automatically executed in order to set-up the gas burner appliance (10, 10') for an upcoming burner start: decrease during the actual burner-on-phase the fan speed of the fan to a defined fan speed while keeping the mixing ratio of gas and air of the gas/air mixture at the defined mixing ratio thereby decreasing the opening position of the electric or electronic gas flow modulator, keep the electric or electronic gas flow modulator at said decreased opening position and terminate the actual burner-on-phase of the gas burner appliance (10, 10'). decrease during the actual burner-on-phase the fan speed of the fan to a defined fan speed while keeping the mixing ratio of gas and air of the gas/air mixture at the defined mixing ratio thereby decreasing the opening position of the electric or electronic gas flow modulator, keep the electric or electronic gas flow modulator at said decreased opening position and terminate the actual burner-on-phase of the gas burner appliance (10, 10').