Clean out the dust collector of any collected debris if you notice excessive dirt buildup in the filter. Also, make sure to clean the filter by removing it from its holder, and tapping on both the filter holder and filter basket over a trash bin. It may also help to wipe or brush out the filer basket and lid with a damp cloth to ensure that they are clean. If all else fails, you may need a new filter. Check out our replacement filters here. You should change the vacuum filter every 2 months.