An appliance operation signal processing system comprising: an input for receiving an appliance operation signal, the appliance operation signal comprising information relating to operation of an appliance; an output for outputting information relating to a recall status of the appliance; and a processor configured to: monitor an input appliance operation signal for a change in magnitude; identify a component event corresponding to a detected change in magnitude, wherein the component event is a change in state of the appliance or a component in the appliance; determine whether the component event is a sequence start component event by comparing the component event to a list of one or more sequence start component events; extract one or more features from the input appliance operation signal between a sequence start component event and a sequence stop point; and determine information relating to a recall status of the appliance by inputting the one or more features into a first algorithm, wherein the first algorithm comprises a first classifier configured to determine a probability that an appliance corresponds to an appliance model designated as recalled, and wherein determining the information relating to a recall status of the appliance comprises: determining a probability that the appliance corresponds to an appliance model designated as recalled by applying the first classifier to a feature vector comprising the one or more features. an input for receiving an appliance operation signal, the appliance operation signal comprising information relating to operation of an appliance; an output for outputting information relating to a recall status of the appliance; and a processor configured to: monitor an input appliance operation signal for a change in magnitude; identify a component event corresponding to a detected change in magnitude, wherein the component event is a change in state of the appliance or a component in the appliance; determine whether the component event is a sequence start component event by comparing the component event to a list of one or more sequence start component events; extract one or more features from the input appliance operation signal between a sequence start component event and a sequence stop point; and determine information relating to a recall status of the appliance by inputting the one or more features into a first algorithm, wherein the first algorithm comprises a first classifier configured to determine a probability that an appliance corresponds to an appliance model designated as recalled, and wherein determining the information relating to a recall status of the appliance comprises: determining a probability that the appliance corresponds to an appliance model designated as recalled by applying the first classifier to a feature vector comprising the one or more features. monitor an input appliance operation signal for a change in magnitude; identify a component event corresponding to a detected change in magnitude, wherein the component event is a change in state of the appliance or a component in the appliance; determine whether the component event is a sequence start component event by comparing the component event to a list of one or more sequence start component events; extract one or more features from the input appliance operation signal between a sequence start component event and a sequence stop point; and determine information relating to a recall status of the appliance by inputting the one or more features into a first algorithm, wherein the first algorithm comprises a first classifier configured to determine a probability that an appliance corresponds to an appliance model designated as recalled, and wherein determining the information relating to a recall status of the appliance comprises: determining a probability that the appliance corresponds to an appliance model designated as recalled by applying the first classifier to a feature vector comprising the one or more features.