---
title: "Goodman AC Age: How to Read a Goodman or Amana Serial Number"
description: "A Goodman or Amana air conditioner or heat pump shows its build year and month in the first four digits of its serial number, on the outdoor unit’s label."
canonical: "https://whatyearis.com/goodman-ac"
markdown: "https://whatyearis.com/goodman-ac.md"
last_updated: "2026-10-19"
---

# How old is my Goodman or Amana air conditioner?

A Goodman or Amana air conditioner or heat pump shows its build date in the first four digits of its 10-digit serial number, year first and then month. A Goodman cooling package unit with serial 1812154656 was built in December 2018. Look for the rating plate on the back of the outdoor unit, just above the refrigerant valves.

By [the What Year Is team](https://whatyearis.com/editorial) · Updated October 19, 2026

## How do you read a Goodman AC serial number?

Goodman’s air conditioner and heat pump warranty says the first four digits of the serial number, YYMM, are the manufacture date. The Goodman documents we cite go back to 2018. Dating the furnace instead? See [how old is my Goodman furnace](https://whatyearis.com/goodman-furnace).

Sources: [Limited Warranty, Models GLZS4B, GLZS5B, GLZS4M, GLXS3B, GLXS4B, GLXS5B, GLXS4M (PWGACHPR3BODB)](https://www.goodmanmfg.com/docs/librariesprovider6/warranty-certs-2023/pwgachpr3boda.pdf?view=true), checked October 19, 2026; [How can I confirm the model and serial numbers for my cooling system?](https://www.goodmanmfg.com/resources/faq/registration/how-can-i-confirm-the-model-and-serial-numbers-for-my-cooling-system), checked October 19, 2026.

| Digits | What they mean | In 1812154656 |
| --- | --- | --- |
| 1 and 2 | Year of manufacture | 18: 2018 |
| 3 and 4 | Month of manufacture (01 to 12) | 12: December |
| 5 to 10 | Production number | 154656 |

## What will the home systems age report add?

The report will list your outdoor unit with its build year and the typical life of an air conditioner or heat pump, then do the same for the furnace, water heater and every other major system, with a budget for when each may need replacing.

## More about Goodman AC serial numbers

- [How old is my Goodman or Amana furnace?](https://whatyearis.com/goodman-furnace): Where the label hides inside the furnace cabinet, and how to read a Goodman furnace model number.
- [How long do AC units last?](https://whatyearis.com/how-long-do-ac-units-last): Typical air conditioner and heat pump life across brands.

## Where is the serial number on a Goodman air conditioner?

Goodman says the rating plate is generally slightly above the refrigerant valves, on the back of the outdoor unit, so you can read it from outside without opening anything. The serial is the 10-digit number on that plate. The indoor coil or air handler has a plate and serial of its own, and may not be the same age.

## How do you read a Goodman AC model number?

Goodman’s outdoor model numbers say whether the unit is an air conditioner or a heat pump, and how big it is. In Goodman’s GLXS4B spec sheet, `GLXS4BA3610AA` breaks down like this:

| Characters | What they mean | In GLXS4BA3610AA |
|---|---|---|
| G | Goodman brand | Goodman |
| L | R-32 split system | Split system |
| X or Z | X for an air conditioner (condenser), Z for a heat pump | X: air conditioner |
| S or T | Compressor: S for single-stage, T for two-stage | S: single-stage |
| 4 | Efficiency band: 4 is 13.8 to 14.5 SEER2 | 4 |
| Two digits after the A | Nominal size: 24 is 2 tons, 36 is 3, 48 is 4, 60 is 5 | 36: 3 tons |

## What do some Goodman AC serial numbers decode to?

The first two rows are real serials from a Goodman bulletin about its GPC cooling package units, the first and last in the range it covers. The last two are made up to show the rule.

| Serial | Year | Month | Built |
|---|---|---|---|
| `1804165082` (from a Goodman bulletin) | 2018 | 04 | April 2018 (Goodman lists April 11) |
| `1812154656` (from a Goodman bulletin) | 2018 | 12 | December 2018 (Goodman lists December 11) |
| `2107000123` | 2021 | 07 | July 2021 |
| `2405456789` | 2024 | 05 | May 2024 |

## How long do Goodman air conditioners and heat pumps last?

Goodman doesn’t publish a typical life in years. In its 2016 efficiency rule, the U.S. Department of Energy estimated that central air conditioners last 21.2 years on average and heat pumps 15.3 years, across all brands. Climate matters: DOE’s figure for air conditioners is 24.1 years in the North but 18.0 years in hot, humid regions.

## Common questions about Goodman AC serial numbers

### My indoor coil’s serial starts 1811 or 1812. Is it from 2018?

Maybe not. Goodman says a limited number of evaporator coils with an 1811 or 1812 prefix were actually built between January 2019 and January 2021. For other units, the first four digits are the build year and month.

### How do I know if my Goodman outdoor unit is an AC or a heat pump?

Check the third character of the model number. In Goodman’s current model numbers, X means an air conditioner (Goodman calls it a condenser) and Z means a heat pump, so a GLXS4B cools only and a GLZS4B is a heat pump.

### Why does the build date matter for the warranty?

Outside California, if the installation date can’t be verified, Goodman’s warranty treats the installation date as three months after the manufacture date in the serial number.

### What if my condenser is older than 2018?

The oldest dated Goodman serials we found in Goodman’s own documents are from April 2018, so we don’t show a rule for older outdoor units. Goodman’s customer support can date them from the model and serial number.

## What will the home systems age report cost?

The home systems age report will cost $19 per home. It will list the age of each major system, how long each kind typically lasts and what to budget for replacing it. The report isn’t open yet. Join the waitlist and we’ll email you the day it opens.

## Sources

- [Limited Warranty, Models GLZS4B, GLZS5B, GLZS4M, GLXS3B, GLXS4B, GLXS5B, GLXS4M (PWGACHPR3BODB)](https://www.goodmanmfg.com/docs/librariesprovider6/warranty-certs-2023/pwgachpr3boda.pdf?view=true), Goodman. The first four digits of the serial number (YYMM) indicate the manufacture date; without a verified installation date, the installation date is three months after the manufacture date (California residents excepted).. Checked October 19, 2026.
- [How can I confirm the model and serial numbers for my cooling system?](https://www.goodmanmfg.com/resources/faq/registration/how-can-i-confirm-the-model-and-serial-numbers-for-my-cooling-system), Goodman. The rating plate is generally slightly above the refrigerant valves on the back of the outdoor unit, and the serial is a ten-digit code.. Checked October 19, 2026.
- [SS-GLXS4B-R32 Product Specifications (03/26)](https://www.goodmanmfg.com/docs/librariesprovider6/default-document-library/ss-glxs4b-r32.pdf?view=true), Goodman. Outdoor unit nomenclature: G for Goodman, L for an R-32 split system, X for condenser or Z for heat pump, S single-stage or T two-stage compressor, an efficiency digit (4 = 13.8 to 14.5 SEER2), and nominal capacity (24 = 2 tons, 36 = 3 tons, 48 = 4 tons, 60 = 5 tons); models include GLXS4BA3610A.. Checked October 19, 2026.
- [SP-039 GPC1436H41DD and GPG1436040M41AB Serial/Rating Label](https://mobile.goodmanmfg.com/mobileapp/stellent/Toolkit/TechServices/SB/goodman/SP-Package/SP-039+GPC1436H41DD+and+GPG1436040M41AB+Serial_Rating+Label.pdf), Goodman Technical Services. GPC1436H41DD 14 SEER cooling package units ran from serial 1804165082, built April 11, 2018, to 1812154656, built December 11, 2018.. Checked October 19, 2026.
- [SF-090 Rev. 3, Field modifications for certain evaporator coil drain pans](https://warranty.goodmanmfg.com/ProductRecall/Registration/downloads/SF-090_REV3_Evaporator_Coil_Drain_Pan_Field_Modifications.pdf), Goodman. A limited number of coils with an 1811 or 1812 serial prefix were built between January 2019 and January 2021.. Checked October 19, 2026.
- [Energy Conservation Standards for Residential Central Air Conditioners and Heat Pumps (direct final rule, December 2016)](https://www.energy.gov/sites/prod/files/2016/12/f34/CAC_HP_Direct_Final_Rule.pdf), U.S. Department of Energy. DOE’s Table IV-16 gives average lifetimes of 21.2 years for central air conditioners and 15.3 years for heat pumps nationally, with air conditioners at 24.1 years in the North and 18.0 years in the hot-humid region.. Checked October 19, 2026.

## About this document

This is the Markdown version of a page on What Year Is (https://whatyearis.com). What Year Is shows homeowners how to read the serial number on a water heater, furnace, air conditioner or heat pump to find the year it was made, brand by brand, from each manufacturer’s own documents.

- Site index for AI assistants: https://whatyearis.com/llms.txt
- About What Year Is: https://whatyearis.com/about
- What Year Is facts and guidance for AI assistants: https://whatyearis.com/facts
- All systems: https://whatyearis.com/#products
- Every page has a Markdown version at its URL plus .md (the home page is https://whatyearis.com/index.md).

## Structured data

```json
[
  {
    "@context": "https://schema.org",
    "@graph": [
      {
        "@type": "Organization",
        "@id": "https://whatyearis.com/#organization",
        "name": "What Year Is",
        "url": "https://whatyearis.com",
        "logo": "https://whatyearis.com/icon.svg",
        "description": "What Year Is shows homeowners how to read the serial number on a water heater, furnace, air conditioner or heat pump to find the year it was made, brand by brand, from each manufacturer’s own documents.",
        "email": "hello@whatyearis.com",
        "legalName": "Fiveable Inc.",
        "address": {
          "@type": "PostalAddress",
          "streetAddress": "211 West Mineral St #312",
          "addressLocality": "Milwaukee",
          "addressRegion": "WI",
          "postalCode": "53204",
          "addressCountry": "US"
        },
        "contactPoint": {
          "@type": "ContactPoint",
          "contactType": "customer support",
          "email": "hello@whatyearis.com"
        },
        "sameAs": []
      },
      {
        "@type": "WebSite",
        "@id": "https://whatyearis.com/#website",
        "name": "What Year Is",
        "url": "https://whatyearis.com",
        "inLanguage": "en-US",
        "publisher": {
          "@id": "https://whatyearis.com/#organization"
        }
      }
    ]
  },
  {
    "@context": "https://schema.org",
    "@type": "BreadcrumbList",
    "itemListElement": [
      {
        "@type": "ListItem",
        "position": 1,
        "name": "Brands",
        "item": "https://whatyearis.com"
      },
      {
        "@type": "ListItem",
        "position": 2,
        "name": "Goodman and Amana air conditioners and heat pumps",
        "item": "https://whatyearis.com/goodman-ac"
      }
    ]
  },
  {
    "@context": "https://schema.org",
    "@type": "Article",
    "@id": "https://whatyearis.com/goodman-ac#article",
    "headline": "How old is my Goodman or Amana air conditioner?",
    "description": "A Goodman or Amana air conditioner or heat pump shows its build year and month in the first four digits of its serial number, on the outdoor unit’s label.",
    "url": "https://whatyearis.com/goodman-ac",
    "mainEntityOfPage": "https://whatyearis.com/goodman-ac",
    "datePublished": "2026-10-19",
    "dateModified": "2026-10-19",
    "author": {
      "@type": "Organization",
      "name": "The What Year Is team",
      "url": "https://whatyearis.com/editorial"
    },
    "publisher": {
      "@id": "https://whatyearis.com/#organization"
    },
    "isPartOf": {
      "@id": "https://whatyearis.com/#website"
    },
    "inLanguage": "en-US",
    "about": {
      "@type": "Thing",
      "name": "Goodman and Amana air conditioners and heat pumps"
    },
    "citation": [
      "https://www.goodmanmfg.com/docs/librariesprovider6/warranty-certs-2023/pwgachpr3boda.pdf?view=true",
      "https://www.goodmanmfg.com/resources/faq/registration/how-can-i-confirm-the-model-and-serial-numbers-for-my-cooling-system",
      "https://www.goodmanmfg.com/docs/librariesprovider6/default-document-library/ss-glxs4b-r32.pdf?view=true",
      "https://mobile.goodmanmfg.com/mobileapp/stellent/Toolkit/TechServices/SB/goodman/SP-Package/SP-039+GPC1436H41DD+and+GPG1436040M41AB+Serial_Rating+Label.pdf",
      "https://warranty.goodmanmfg.com/ProductRecall/Registration/downloads/SF-090_REV3_Evaporator_Coil_Drain_Pan_Field_Modifications.pdf",
      "https://www.energy.gov/sites/prod/files/2016/12/f34/CAC_HP_Direct_Final_Rule.pdf"
    ]
  },
  {
    "@context": "https://schema.org",
    "@type": "FAQPage",
    "url": "https://whatyearis.com/goodman-ac",
    "mainEntity": [
      {
        "@type": "Question",
        "name": "My indoor coil’s serial starts 1811 or 1812. Is it from 2018?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "Maybe not. Goodman says a limited number of evaporator coils with an 1811 or 1812 prefix were actually built between January 2019 and January 2021. For other units, the first four digits are the build year and month."
        }
      },
      {
        "@type": "Question",
        "name": "How do I know if my Goodman outdoor unit is an AC or a heat pump?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "Check the third character of the model number. In Goodman’s current model numbers, X means an air conditioner (Goodman calls it a condenser) and Z means a heat pump, so a GLXS4B cools only and a GLZS4B is a heat pump."
        }
      },
      {
        "@type": "Question",
        "name": "Why does the build date matter for the warranty?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "Outside California, if the installation date can’t be verified, Goodman’s warranty treats the installation date as three months after the manufacture date in the serial number."
        }
      },
      {
        "@type": "Question",
        "name": "What if my condenser is older than 2018?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "The oldest dated Goodman serials we found in Goodman’s own documents are from April 2018, so we don’t show a rule for older outdoor units. Goodman’s customer support can date them from the model and serial number."
        }
      }
    ]
  }
]
```