HVAC Label Guide

Goodman and Amana date code: YYMM in the first four digits

Goodman states that “the first four digits of the serial number (YYMM) on the unit indicate the manufacture date.” Its example: a serial starting “2301” was built in January 2023.

Manufacture date, not install date or warranty status. A date code tells you when the maker built the unit. It does not tell you when it was installed, whether any warranty applies, or what condition the unit is in.

The rule

DigitsMeaningGoodman's example
1–2Year (YY)23
3–4Month (MM)01 = January

Source: Goodman document PWGACHPTTYURC, dated 01/2023 (PDF) (accessed 2026-10-27), for Goodman models GSX13, GSX14, GSX16, GSZ14, GSZ16, GSXN3, GSXN4, GSXB4, GSXM4, GSZB4, GSZM4, GSXH5 and GSZH5.

An older Goodman document for Amana brand units (models RHF and PHD, copyright 2003–2006) uses the same rule. It refers to the “month of manufacture (as indicated by the first four digits of the serial number (yymm)).”

Source: Goodman document PW-346 (PDF) (accessed 2026-10-27). Both documents are Goodman warranty papers. We cite them only for the serial rule.

Read your code

Type the serial to see the month and year.

The reader uses only the maker's rule shown on this page. It reads a two-digit year as 20xx, or 19xx when 20xx would be in the future. It runs in your browser and sends nothing anywhere. Manufacture date only.

Where to find the serial

Goodman says the model and serial number are on the rating plate of your air conditioner or heat pump, “generally found slightly above the refrigerant valves on the back side of the unit.” It describes the serial as “a ten digit code that helps us identify the time the unit was produced.”

Source: Goodman FAQ, How can I confirm the model and serial numbers for my cooling system? (accessed 2026-10-27).

Limits

The rule comes from documents that name specific Goodman and Amana models. Other Goodman-made lines may use the same layout, but we have not seen a Goodman document that says so for every product. If the first four digits do not form a valid month, the rule does not fit that serial.

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Sources

  1. Goodman, PWGACHPTTYURC, 01/2023 (PDF): https://mobile.goodmanmfg.com/mobileapp/stellent/pdf/infoPdf/Lit/PWGACHPTTYURC.pdf, accessed 2026-10-27
  2. Goodman, PW-346, Amana brand RHF and PHD (PDF): https://mobile.goodmanmfg.com/mobileapp/stellent/pdf/infoPdf/Lit/PW-346.pdf, accessed 2026-10-27
  3. Goodman, FAQ on model and serial numbers: https://www.goodmanmfg.com/resources/faq/registration/how-can-i-confirm-the-model-and-serial-numbers-for-my-cooling-system, accessed 2026-10-27

Last checked 2026-10-27. Other makers: Rheem, Bradford White, A. O. Smith.