A Maytag wringer washer with the model number 23598 BU was manufactured in September 1990. The first letter of the series provides the year, and the second letter provides the month.
Model numbers for Maytag appliances are necessary to determine year of manufacture, to order replacement parts and to determine the value of the washer. Different manufacturers tend to place the serial and model plates in different areas on the washer.
The energy guide that comes with some Maytag appliances may not contain the entire model or serial number; the guide usually contains a shortened version that does not provide dating information.