An appliance may be monitored or controlled with an appliance assistant. The appliance assistant may include a sensor that measures data corresponding to power being consumed by the appliance and transmit information about the operational state of the appliance to a server computer. Users of the appliance may have mobile devices that may be configured to provide location information, such as a location or whether the mobile device is in the vicinity of the appliance. A server may receive information about the operational state of the appliance from the appliance assistant and location information from mobile devices. The server may determine to cause an action to be performed using this information, such as sending a notification or causing the appliance assistant to disconnect the appliance from a power source.