There are two filters in the cleaner, they need to be kept clean to give the best suction power and dirt pick up. One is located in the dust box, start by removing the dust container from the machine.
Open the dust box and remove the filter. For best results wash the filter in warm water to remove all the debris. Hoover suggest you replace the filter once per year and fresh filters can be purchased from the spares section of the website.
Before you refit the dust box lift out the exhaust filter found at the front of the product under where the dust box fits.
The exhaust filter (blue) can be lifted up to remove for cleaning. Wash in warm water for best results. All filters should be thoroughly dry before putting them back into the product - this can take up to 24 hours.