Cleaning device for cleaning a surface, the cleaning device being operable in at least a wet operation mode and comprising: - at least one cleaning element configured to perform a cleaning action on the surface to be cleaned, - a wetting system configured to supply a cleaning liquid to an area where the at least one cleaning element is located to thereby realize a wet cleaning condition of the at least one cleaning element in the wet operation mode of the cleaning device, wherein the wetting system is operable in one of at least one normal operation mode and a boost operation mode involving an increased supply rate of the cleaning liquid with respect to the at least one normal operation mode, and - a controlling system configured to control operation of the cleaning device according to an operation program, wherein the operation program includes a wet operation mode algorithm involving a sequence of start-up steps to be taken when the wet operation mode of the cleaning device is initiated, and wherein the start-up steps comprise - retrieving an actual value of at least one parameter that is indicative of whether or not the at least one cleaning element is in the wet cleaning condition, - determining a start-up operation mode of the wetting system to be one of the at least one normal operation mode or the boost operation mode by relating the actual value of the at least one parameter to an operation mode of the wetting system according to a predetermined relation between values of the at least one parameter and the respective operation modes of the wetting system, and - controlling the wetting system to operate in the start-up operation mode. - at least one cleaning element configured to perform a cleaning action on the surface to be cleaned, - a wetting system configured to supply a cleaning liquid to an area where the at least one cleaning element is located to thereby realize a wet cleaning condition of the at least one cleaning element in the wet operation mode of the cleaning device, wherein the wetting system is operable in one of at least one normal operation mode and a boost operation mode involving an increased supply rate of the cleaning liquid with respect to the at least one normal operation mode, and - a controlling system configured to control operation of the cleaning device according to an operation program, wherein the operation program includes a wet operation mode algorithm involving a sequence of start-up steps to be taken when the wet operation mode of the cleaning device is initiated, and wherein the start-up steps comprise - retrieving an actual value of at least one parameter that is indicative of whether or not the at least one cleaning element is in the wet cleaning condition, - determining a start-up operation mode of the wetting system to be one of the at least one normal operation mode or the boost operation mode by relating the actual value of the at least one parameter to an operation mode of the wetting system according to a predetermined relation between values of the at least one parameter and the respective operation modes of the wetting system, and - controlling the wetting system to operate in the start-up operation mode.