Weil-McLain®

How to determine the date of production/manufacture or age of Weil-McLain® 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

Note that 6-digit CP numbers are generally from the early 1980's and prior. You will typically need to contact Weil-McLain directly for manufacture date assistance on any 6-digit CP numbers encountered, or use other methods such as date stamps on the gas valve etc. Our History information below may also be of assistance to narrow the approximate range of manufacture. ALL information on the data plate and system will be critical to help determine the age.

Back to Brand Listing
 

Style 1:   CP 2530051

The Date of Manufacture is determined from the units CP/Serial Number which runs consecutively.  The CP numbers are commonly found on a separate tag or sticker apart from the typical data tag.
We have included an abbrevbiated chart listing CP numbers from 1988 through 2009 (see below) for your convenience.  In addition Weail-McLain also has a CP number Look-up Tool available on their wesite.

Note that 6-digit CP numbers are generally from the early 1980's and prior. The Look-up tool site below may be of assistance, but you will typically need to contact Weil-McLain directly for manufacture date assistance, or use other methods such as date stamps on the gas valve etc. Our History information below may also be of assistance to narrow the approximate range of manufacture.

 

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.

Weil-McLain History
  • 1881 - Founded by Isadora and Benjamin Weil as a small plumbing and heating house in Chicago, Illinois, under the name “Weil Brothers”
  • 1918 -  Bought out their largest boiler supplier, J. H. McLain Company of Canton, Ohio
  • 1919 - The company name “Weil-McLain” was established
  • 1921 -  Weil-McLain moved the boiler operations from Canton, Ohio to the present facilities in Michigan City, Indiana
  • 1927 - added a foundry operation in Erie, Pennsylvania
  • 1953 - the company sold its wholesale operation to focus on manufacturing
  • 1964 - Weil-McLain started acquiring companies
  • 1966 - the boiler operations became known as the “Hydronics Division” of Weil-McLain
  • 1976 - the corporate name was changed to Wylain, Inc. of which Weil-McLain became a division (data plates state "Weil-McLain, a division of Wylain, Inc.")
  • 1980 - in late December, 1979, Wylain, Inc. announces agreement to a takeover (merger) by The Marley Company of Mission Woods, Kansas (manufacturer of cooling towers and heat exchangers) in a transaction valued at $93.8 million. Wylain would be merged into a wholly owned subsidiary of Marley. The company name was changed to Weil-McLain a division of The Marley Company
  • 1981 - Marley Company mergers and corporate name changed to Marley-Wylain Company
  • 1993 - United Dominion Industries of Charlotte, North Carolina, purchased The Marley-Wylain Company
  • 1999 - Weil-McLain expanded its boiler line and entered the oil furnace market by acquiring Williamson Thermoflo
  • 2001 - United Dominion Industries was acquired by SPX Corporation of Charlotte, North Carolina. Weil-McLain is now "Weil-McLain, a division of The Marley-Wylain Company, a subsidiary of SPX Corporation"
  • 2005 - after outgrowing the original Michigan City manufacturing facility, Weil-McLain opened a manufacturing plant and distribution facility in Eden, North Carolina. The Michigan City, Indiana location continues its cast iron foundry operations and houses a state of the art laboratory and testing facilities alongside an engineering and development center.
  • 2012 - Weil-McLain opened an administrative office in Burr Ridge, Illinois (a suburb of Chicago).

Page last updated: 5/06/2021