Which item is essential identifying information for an appliance?

The essential identifying information for an appliance is the manufacturer. The manufacturer's information provides critical details about the appliance, including its design, specifications, and any safety standards it meets. This identification is key in investigating incidents involving appliances, as it allows for tracing the device's history, finding recall information, and determining possible defects or safety concerns associated with that particular brand or model.

While the owner's name, installation date, and location of the appliance can provide additional context during an investigation, they do not uniquely identify the appliance in the same way that the manufacturer's name does. The manufacturer is crucial because it links the appliance to its production, potentially revealing patterns or issues related to other units of the same make and model. This information is vital for thorough investigations into appliance-related fires or malfunctions.