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Information on Old Trane Air Conditioners

Linda Richard

Reuben Trane started his air-conditioning business in 1931, and Trane has made significant improvements to air conditioners over its 80 years in business. Trane doesn’t sell central air conditioners direct to the public, but has dealers who sell and install units. You can date a Trane air-conditioning unit by serial number as far back as 1980. Although Trane units work for years, any unit older than 1980 isn't likely in operation or needs replacement with higher-efficiency equipment.

Owners' Manuals

Trane has owners' manuals available for older Trane air conditioners. Look on your unit for the model and serial number and give the dealer or local installer the approximate date of installation of the unit. The serial number is on the top right rear of the outdoor unit on a metal plate. You can find the year of manufacture from the serial number. Locate the serial number on the Trane indoor air handler on the front panel.

Date of Manufacture

Use the seventh number of the serial number to find the manufacturing date of Trane equipment from the early 1980s. The letters “O”, “T” and “U” signify the 1980, 1981 and 1982 units. Units from 1983 to 2002 have a starting letter identifying the date; units manufactured in 2002 or later use a starting number for date identification. The letters “W”, “X” and “Y” and “S” are for 1983, 1984, 1985 and 1986. From 1987 through 1993, the letters are in sequence from “B” through “H.” For example, 1990 units begin with the letter “E.” A 2002 manufacturing date begins with the number “2” and units through 2009 begin with the corresponding number for the year. Serial numbers for 2009 units begin with the number “9.”


You or the previous owner may have registered an older Trane unit with Trane for limited warranty protection. An optional extended warranty provides coverage in 5-year or 10-year increments, covering parts and labor for the duration of the agreement. Extended warranty coverage is transferable to a new owner. Even a unit more than 10 years old may have some warranty coverage.


The federal Energy Savers website reports that replacement of central air conditioning more than 10 years old may save 20 to 40 percent on your energy bill. The Seasonal Energy Efficiency Ratio compares different brands for efficiency, and the federal government mandates efficiency standards. The SEER rating combines the outdoor unit with the indoor coil to figure system efficiency. Trane units manufactured before 2006 don't likely have the efficiency rating of the newer units. The federal government increased efficiency standards from 10 SEER to 13 SEER effective January 2006. Federal rules changing the testing process take effect January 2015, dividing test groups into single-speed compressor, two-capacity compressor and variable-speed compressor to compare efficiency results.