The average lifespan of the filter is six to nine months depending on use. When the filter has changed from green to blue (or has a solid rather than speckled appearance), it is time to replace it.
Using distilled water may extend the life of the filter.
A replacement filter can be ordered from BISSELL Consumer Services either online at www.bissell.com under the Parts and Accessory tab or by calling 1-800-237-7691 Monday through Friday from 8 A.M. to 10 P.M. or Saturdays from 9 A.M. to 8 P.M. ET.