Weil-McLain®

How to determine the date of production/manufacture or age of Alton® HVAC Systems.

The date of production/manufacture or age of Weil-McClain® HVAC equipment can be determined from the CP/Serial number located on the data plate.

Parent Company:  Weil-McLain, a division of The Marley-Wylain Company

Example serial number styles/formats found:

  • Style 1:    CP 2530051

Style 1:   CP 2530051

Unfortunately we are unable to determine the date of manufacture or age of these units. The Date of Manufacture is determined from the units CP/Serial Number which runs consecutively.  The CP #’s are commonly found on a separate tag or sticker apart from the typical data tag.
We have included an abbrevbiated chart listing CP #,s from 1988 through 2009 (see below) for your convenience.  In addition Weail-McLain also has a CP # Look-up Tool available on their wesite.  WARNING:  NOT TO BE USED FOR OTHER Weil-McClain or Marley-Wylain Company brands.

Click To Go: CP # Look-up tool

You can also use the ANSI or CSA standards to determine approximate Date of Manufacture.
Most manufacturers today are required to include the manufacture compliance standard on the data tag. For the U.S. the compliance standard is typically from the American National Standards Institute (ANSI). For Canada, a common standard compliance is through the Canada Standards Association Group (CSA). Many times both standards are listed. Regardless, the specific standard will normally be listed on the data tag/plate and followed by the YEAR of the last revision (often the year is placed in parenthesis or follows the hyphen after the specific standard number). As these standards are revised or renewed approximately every 4 to 6 years, one can reasonably estimate the year of manufacture within 4-6 years from (after) the standards date.
If you still require further assistance in determining age or manufacture date, contact Weil-McLain at -(219) 879-6561 or (866) 783-9276 and ask for Technical Services.

Page last updated: 7/30/2017

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