Most washing machines have a drain filter that can become clogged over time. Try to locate and clean it. Front load washers typically have a small removable panel about the size of a half sheet of paper on the bottom front of the machine. The filter is inside. Top load washers are typically located in the back somewhere but can be more difficult to find. Use caution because once you remove the filter there will most likely be several gallons of water waiting to rush out.
