A combination washing and drying appliance comprising: an outer cabinet ; a tub positioned within the outer cabinet , the tub having a wall and an air outlet through a portion, in particular an upper portion , of the wall , wherein a sump is defined within a portion, in particular a lower portion , of the tub , the sump having a drain configured to move wash fluid from the inside of the tub to an external outlet ; a drum configured to rotationally operate within the tub , the sump being in particular defined below the drum ; an airflow path , the airflow path being in particular in fluid communication with the inside of the tub ; an air handling system attached to the wall of the tub and configured to draw process air from the inside of the tub and through the air outlet to the airflow path ; a lint filter disposed within the air outlet and configured to filter particulate from process air entering the airflow path ; a fluid delivery system having a valve configured to operate to deliver wash fluid into the inside of the tub ; and a fluid pump coupled with the sump and configured to direct wash fluid to the external outlet , wherein: during a filter cleaning phase of the appliance , the fluid delivery system is configured to deliver impulse amounts of the wash fluid to deliver the wash fluid to the sump and to maintain the wash fluid between an outer surface of the drum and an inside surface of the tub ; the drum is configured to operate to direct the wash fluid in the sump around the drum and along the inside surface of the tub and over an interior surface of the lint filter to remove particulate from the lint filter ; the fluid pump is configured to direct particulate to the external outlet , in particular wherein particulate is directed by the fluid pump to the external outlet together with wash fluid . an outer cabinet ; a tub positioned within the outer cabinet , the tub having a wall and an air outlet through a portion, in particular an upper portion , of the wall , wherein a sump is defined within a portion, in particular a lower portion , of the tub , the sump having a drain configured to move wash fluid from the inside of the tub to an external outlet ; a drum configured to rotationally operate within the tub , the sump being in particular defined below the drum ; an airflow path , the airflow path being in particular in fluid communication with the inside of the tub ; an air handling system attached to the wall of the tub and configured to draw process air from the inside of the tub and through the air outlet to the airflow path ; a lint filter disposed within the air outlet and configured to filter particulate from process air entering the airflow path ; a fluid delivery system having a valve configured to operate to deliver wash fluid into the inside of the tub ; and a fluid pump coupled with the sump and configured to direct wash fluid to the external outlet , during a filter cleaning phase of the appliance , the fluid delivery system is configured to deliver impulse amounts of the wash fluid to deliver the wash fluid to the sump and to maintain the wash fluid between an outer surface of the drum and an inside surface of the tub ; the drum is configured to operate to direct the wash fluid in the sump around the drum and along the inside surface of the tub and over an interior surface of the lint filter to remove particulate from the lint filter ; the fluid pump is configured to direct particulate to the external outlet , in particular wherein particulate is directed by the fluid pump to the external outlet together with wash fluid . <EOS>