Take out the HEPA filter.Turn the filter over so that the dirty side is on the bottom and vigorously tap it clean against a garbage can to remove any dust. Wash the filter under the tap using lukewarm water with the dirty side face down until the water runs clear. DO NOT put the filter in the washing machine or dishwasher. NOTE: The material in the filter will discolor over time. This is NORMAL and will not affect the performance of the filter. Allow the filter to air dry for 24 hours. Do not use a hair dryer or other heating methods to dry. Once the HEPA filter is dry, replace it back into the vacuum.