Goodman has the simplest serial number format in the HVAC industry: the first four digits are always YYMM — year then month. Serial number 2205123456 means your Goodman was manufactured in May 2022. This same format works for Amana and Daikin residential units, since all three brands are made by Daikin Industries.
Here's how to find your serial number, decode it, and understand what your Goodman's age means for maintenance, warranty, and replacement decisions.
Where to Find Your Goodman Serial Number
| Equipment | Location |
|---|---|
| Central AC (outdoor condenser) | Data plate on the side panel — usually the upper left or right side |
| Heat pump (outdoor unit) | Same as AC — side panel of outdoor unit |
| Furnace | Inside the front cabinet door or on the left side panel |
| Air handler | Side panel or inside the access door |
| Package unit | Side panel of the outdoor unit |
The data plate is a metal or adhesive label showing the model number, serial number, refrigerant type, electrical specifications, and manufacture date. On Goodman units, the serial number is typically 10 digits.
How to Decode a Goodman Serial Number
The Format: YYMM + Sequence
| Position | Characters | Meaning |
|---|---|---|
| 1st–2nd digits | Year | Last two digits of the manufacture year |
| 3rd–4th digits | Month | Month of manufacture (01–12) |
| 5th–10th digits | Sequence | Production sequence number |
That's it. No letter codes, no cycling, no ambiguity.
Complete Decoding Table
| First 4 Digits | Manufacture Date | System Age (as of 2026) |
|---|---|---|
| 2601 | January 2026 | Brand new |
| 2512 | December 2026 | Under 1 year |
| 2506 | June 2026 | Under 1 year |
| 2401 | January 2024 | 2 years |
| 2306 | June 2023 | ~2.5 years |
| 2201 | January 2022 | 4 years |
| 2007 | July 2020 | ~5.5 years |
| 1903 | March 2019 | ~7 years |
| 1711 | November 2017 | ~8 years |
| 1605 | May 2016 | ~10 years |
| 1408 | August 2014 | ~11.5 years |
| 1201 | January 2012 | 14 years |
| 1006 | June 2010 | ~16 years |
| 0803 | March 2008 | ~18 years |
| 0509 | September 2005 | ~20 years |
More Real-World Examples
| Full Serial Number | Decoded Date | Notes |
|---|---|---|
| 2205123456 | May 2022 | Mid-life, under warranty if registered |
| 1908567890 | August 2019 | 7 years old, still under 10-year warranty |
| 1601234567 | January 2016 | 10 years — warranty just expired |
| 0806987654 | June 2008 | 18 years old, uses R-22, replace ASAP |
| 2601111111 | January 2026 | Brand new, R-454B refrigerant |
Pro tip for Goodman: Unlike some brands where the serial number format changed over the decades, Goodman has used this YYMM format consistently since the late 1990s. If the first two digits make sense as a year (97, 98, 99, 00–26), you've got it right.
Amana Serial Numbers (Same Format)
Amana is Goodman's sister brand — both owned by Daikin — and uses the identical YYMM format.
| Amana Serial Number | Decoded Date |
|---|---|
| 2109456789 | September 2021 |
| 1803111222 | March 2018 |
| 1412333444 | December 2014 |
The only difference between Goodman and Amana is branding, available model tiers, and warranty (Amana offers a lifetime compressor warranty on premium models, while Goodman offers 10 years).
Goodman Model Number Decoding
While the serial number gives you the date, the model number reveals your system's specifications:
AC/Heat Pump Model Number Breakdown
Example: GSXN403610
| Characters | Meaning | Decoded |
|---|---|---|
| G | Goodman brand | Goodman |
| SX | Product type (SX = split system AC) | Air conditioner |
| N | Series/revision | N-series |
| 4 | Refrigerant (4 = R-410A) | R-410A |
| 036 | Capacity in thousands BTU/hr | 3 tons (36,000 BTU) |
| 10 | Configuration | Standard |
Common Goodman Model Prefixes
| Prefix | Product Type | Notes |
|---|---|---|
| GSX | Central air conditioner | Split system |
| GSZ | Heat pump | Split system |
| GPC | Package AC | Packaged system |
| GPH | Package heat pump | Packaged system |
| GMS, GME | Gas furnace | Single/multi-speed |
| GMV | Gas furnace | Variable-speed |
| GDH | Ductless mini split | Daikin/Goodman branded |
Tonnage From Model Number
| Code in Model | Tons | BTU/hr |
|---|---|---|
| 018 | 1.5 | 18,000 |
| 024 | 2.0 | 24,000 |
| 030 | 2.5 | 30,000 |
| 036 | 3.0 | 36,000 |
| 042 | 3.5 | 42,000 |
| 048 | 4.0 | 48,000 |
| 060 | 5.0 | 60,000 |
Goodman Product Lines by Efficiency
| Series Code | Line | SEER2 | Compressor |
|---|---|---|---|
| GSXN4 | Economy | 14.3 | Single-stage |
| GSXH5 | Standard | 15.2 | Single-stage |
| GSXC7 | Enhanced | 17 | Two-stage |
| GSXV9 | Premium | 19 | Variable-speed |
Goodman Warranty by Age
Goodman's warranty terms depend on whether the original homeowner registered the equipment within 60 days of installation:
| Component | Registered Warranty | Unregistered Warranty |
|---|---|---|
| Compressor | 10 years | 5 years |
| All other parts | 10 years | 5 years |
| Heat exchanger (furnace) | Lifetime | 20 years |
Warranty starts from manufacture date if unregistered. If you bought a home with a Goodman system and the previous owner didn't register the warranty, the warranty period is calculated from the serial number manufacture date, not the installation date. This can cost you 6–12 months of warranty coverage.
Warranty Status by Serial Number
Use your decoded date to check warranty status:
| Serial Starts With | Manufacture Date | Registered Warranty Status (2026) |
|---|---|---|
| 26xx | 2026 | Under warranty |
| 25xx | 2026 | Under warranty |
| 24xx | 2024 | Under warranty |
| 23xx | 2023 | Under warranty |
| 22xx | 2022 | Under warranty |
| 21xx | 2021 | Under warranty |
| 20xx | 2020 | Under warranty |
| 19xx | 2019 | Under warranty |
| 18xx | 2018 | Under warranty |
| 17xx | 2017 | Under warranty (through 2027) |
| 16xx | 2016 | Expired (10 years) |
| 15xx | 2015 | Expired |
Refrigerant Type by Manufacture Date
| Manufacture Year | Refrigerant | Notes |
|---|---|---|
| Before 2010 | R-22 | Phased out — expensive to recharge ($80–$150/lb) |
| 2010–2024 | R-410A | Current standard, being phased down |
| 2026+ | R-454B | New low-GWP standard |
If your Goodman serial number starts with 09 or earlier (2009 or before), your system uses R-22 refrigerant. R-22 is no longer manufactured and existing stockpiles are dwindling. A simple recharge now costs $300–$800. Strongly consider replacing the entire system rather than investing in R-22 recharges.
What Your Goodman's Age Means
Repair vs. Replace Decision Guide
| System Age | Condition | Repair Cost | Recommendation |
|---|---|---|---|
| 0–5 years | Any | Under $1,000 | Repair (under warranty) |
| 6–10 years | Good | Under $600 | Repair |
| 6–10 years | Poor (multiple issues) | Over $600 | Evaluate replacement |
| 11–14 years | Good | Under $400 | Repair with caution |
| 11–14 years | Any | Over $500 | Strong case for replacement |
| 15+ years | Any | Any major repair | Replace |
The $5,000 Rule Applied to Goodman
Multiply the system age × repair cost. If the result exceeds $5,000, replace:
| Serial Number | Age in 2026 | Repair Quote | Age × Repair | Decision |
|---|---|---|---|---|
| 2203xxx | 4 years | $350 capacitor | $1,400 | Repair |
| 1806xxx | 8 years | $500 fan motor | $4,000 | Repair (close) |
| 1504xxx | 11 years | $600 coil leak | $6,600 | Replace |
| 1201xxx | 14 years | $1,800 compressor | $25,200 | Replace |
| 0806xxx | 18 years | Any major | Way over | Replace |
Real-World Examples
Warranty success: Rachel's Goodman AC stopped cooling. Serial: 2003456789 = March 2020. Only 6 years old — well within the 10-year warranty. The contactor had failed. Goodman covered the $45 part; Rachel paid $165 for the service call labor. Total: $165 instead of $210.
Age discovery during home sale: Mark was selling his home and listed the HVAC as "10 years old" from memory. The buyer's inspector decoded the Goodman serial 1405678901 = May 2014 — the system was actually 12 years old. Mark adjusted the price accordingly.
R-22 identification: The Williamses called a tech because their AC was blowing warm air. Serial: 0709123456 = September 2007. The tech found a refrigerant leak and explained the system used R-22 at $100/lb. Instead of spending $600+ on a recharge that might leak again, they replaced the 19-year-old system with a new Goodman GSXN4 for $4,400 installed.
Amana lifetime warranty claim: Janet's Amana (Goodman sister brand) had a compressor failure. Serial: 1608234567 = August 2016. The unit was an Amana AVXC20 with a lifetime compressor warranty. Amana shipped a new compressor at no charge; Janet paid $750 for labor and refrigerant. Without the lifetime warranty, the total would have been $2,500+.
Goodman Error Codes (Common)
If your Goodman furnace is showing error codes, here's a quick reference:
| LED Flashes | Code | Meaning |
|---|---|---|
| Steady ON | Normal | System operating correctly |
| 1 flash | — | System lockout, retry |
| 2 flashes | — | Pressure switch stuck open |
| 3 flashes | — | Pressure switch stuck closed |
| 4 flashes | — | Open high-temperature limit |
| 5 flashes | — | Flame sensed without gas valve call |
| 6 flashes | — | 115V power polarity reversed |
| 7 flashes | — | Gas valve circuit error |
| Continuous ON | — | Control board has 24V but no call for heat |
Key Takeaways:
- Goodman serial numbers are the easiest to decode: first four digits = YYMM (year, month)
- Same format works for Amana (same parent company, Daikin)
- Register your warranty within 60 days — unregistered units get only 5-year coverage vs. 10
- Pre-2010 Goodman units (serial starts with 09 or lower) use R-22 — prioritize replacement
- Goodman systems last 14–18 years on average with proper maintenance
- For model specs, the model number contains tonnage (036 = 3 ton), refrigerant (4 = R-410A), and series info
- Use the $5,000 rule (age × repair cost) to decide between repair and replacement