A cleaning appliance includes a main body, a filter and an interlock. The main body includes an airflow generator, a separating apparatus separating dirt and dust from an airflow, and a flowpath between the separating apparatus and the airflow generator delimited by a wall. The interlock has a first part located on the filter and a second part located on the main body outside the flowpath, arranged to communicate remotely when the filter is correctly located in the pre-determined position. The interlock is arranged selectively to allow or prevent operation of the airflow generator depending upon the relative separation between the first and second parts. By providing an interlock which has first and second parts which communicate remotely, the second part located on the main body can be isolated from the airflow path so that the second part is not subject to dirt and dust carried by the airflow.