How often should I wash the filter, and how do I dry it?

You should wash your filter at least once a month to maintain optimum suction power. After washing with warm running tap water, leave your filter to dry for at least 24 hours in a well-ventilated, warm place. Do not dry your filter in a tumble dryer, microwave, or near a naked flame, and never put the filter back in the machine while it is damp as it could damage your machine. (Page 9)