Trane uses two model-number systems: an S-series format for furnaces (S9V2, S8X1) and a 4TT / 4TW format for outdoor units. Both are short, and both give up capacity, efficiency and cabinet size once you know the positions. This guide decodes Trane furnace and air-conditioner model numbers position by position, using the key Trane prints on its own product data sheets.
Trane and American Standard are the same company. The furnace model numbers are identical (S9V2 is sold under both names) and the outdoor units differ only in the brand letter, so this guide also decodes American Standard equipment. See the American Standard model number guide for that brand's family names.
Where to Find the Trane Model Number
On a furnace, the rating plate is inside the front door or on the side of the cabinet, usually a foil or paper label with the model (M/N) and serial (S/N) side by side. On an outdoor AC or heat pump it is on the side of the condenser near the refrigerant line connections. Copy the model number exactly as printed, including dashes: the position of each character is what carries the meaning.
Trane Furnace Model Number Format
A typical Trane furnace model number looks like: S9V2B080U4PSAA. Use the table to split it up:
| Position | Characters | Meaning | Example |
|---|---|---|---|
| Series | S | S = current S-series gas furnace (legacy units start with T, e.g. TUD, TUH, TDH) | S |
| AFUE family | 9 | 9 = 90%+ condensing; 8 = 80% | 9 (96% AFUE on S9V2) |
| Stages / motor | V2 | V2 = two-stage with variable-speed ECM; X2 = two-stage ECM; X1 = single-stage ECM; B1 = single-stage; V1 = single-stage variable | V2 |
| Cabinet width | B | B = 17.5 in.; C = 21 in.; D = 24.5 in. | 17.5 in. wide |
| Heating input | 080 | Thousands of BTU/h: 040, 060, 080, 100, 120 | 80,000 BTU/h |
| Airflow direction | U | U = upflow / horizontal; D = downflow | U (upflow) |
| Blower capacity | 4 | Nominal cooling tons the blower supports: 3, 4, 5 | 4 tons |
| Configuration | PS | Manufacturer configuration code (not defined on the product data sheet) | PS |
| Revision | AA | Design revision (AA, BB, BD...) | AA |
Buy the same name-brand HVAC system the pros install — shipped factory-direct to your door. No middleman, 5-star rated, and financing available.
Common Trane Furnace Families
The first few characters identify the family, and the family tells you the tier, staging and blower before you read a single digit of capacity.
| Model prefix | Family | Stages | Blower | Efficiency |
|---|---|---|---|---|
| S9V2 | Two-stage variable-speed | Two-stage | Variable-speed ECM | 96-97% AFUE |
| S9X2 | Two-stage ECM | Two-stage | Constant-torque ECM | 96% AFUE |
| S9X1 | Single-stage ECM | Single-stage | Constant-torque ECM | 96% AFUE |
| S9B1 | Single-stage | Single-stage | Multi-speed | 96% AFUE |
| S8X1 / S8B1 | 80% families | Single-stage | ECM / multi-speed | 80% AFUE |
| TUD / TUH / TDH | Legacy XV80, XV95, XL80 etc. | Varies | Varies | 80-95% AFUE |
Trane AC and Heat Pump Model Numbers
Outdoor units use a different string. A typical Trane air conditioner model number looks like: 4TTR6036A1000A.
| Position | Characters | Meaning | Example |
|---|---|---|---|
| Refrigerant | 4 | 4 = R-410A (2 = R-22 on older units) | 4 |
| Brand | T | T = Trane; A = American Standard | T |
| Product type | T | T = split-system air conditioner; W = split-system heat pump | T (AC) |
| Family | R | R = XR series; X = XL series; B = XB series; Z = XV / variable-speed | R (XR) |
| SEER digit | 6 | 3 = 13, 4 = 14, 5 = 15, 6 = 16, 7 = 17, 8 = 18, 0 = 20 | 16 SEER |
| Connections | 0 | 0 = brazed | 0 |
| Cooling capacity | 36 | Thousands of BTU/h; divide by 12 for tons | 36,000 BTU/h = 3 tons |
| Major design | A | Design generation letter | A |
| Power supply | 1 | 1 = 208/230 V single-phase | 208/230-1 |
| Secondary function / revision | 000A | Manufacturer function code plus minor design revision | 000A |
Trane Tonnage by Model Number
Every Trane outdoor unit carries its cooling capacity as a two- or three-digit BTU code. Divide by 12 to get tons (1 ton = 12,000 BTU/h). Furnace numbers carry the gas input instead, so a "080" on a furnace means 80,000 BTU/h of heating, not 80,000 BTU/h of cooling.
| Model code | Size | Cooling capacity |
|---|---|---|
| 018 | 1.5 ton | 18,000 BTU/h |
| 024 | 2 ton | 24,000 BTU/h |
| 030 | 2.5 ton | 30,000 BTU/h |
| 036 | 3 ton | 36,000 BTU/h |
| 042 | 3.5 ton | 42,000 BTU/h |
| 048 | 4 ton | 48,000 BTU/h |
| 060 | 5 ton | 60,000 BTU/h |
Common Trane outdoor families and where they sit:
| Model prefix | Family | Efficiency |
|---|---|---|
| 4TTR4 / 4TTR6 | XR14 / XR16 | 14-16 SEER |
| 4TTX6 / 4TTX8 | XL16i / XL18i | 16-18 SEER |
| 4TTV8 / 4TTV0 | XV18 / XV20i variable-speed | 18-22 SEER |
| 4TWR / 4TWX / 4TWV | XR, XL and XV heat pumps | 14-20 SEER |
What the Trane Model Number Does Not Tell You
The model number says nothing about the unit's age. That is in the serial number, and Trane has changed its serial date format more than once. Use the Trane serial number lookup to turn a serial into a manufacture date, or the HVAC serial number decoder hub for any other brand. The model number also does not tell you whether the unit was installed and charged correctly, which matters as much as the SEER digit for what it actually costs to run.
Decoded Your Trane? Here Is What to Do With It
If the unit is under 10 years old and the model number shows a mid- or high-efficiency family, it is usually worth repairing. If the serial dates it past 12 to 15 years for an AC or 15 to 20 years for a furnace, the capacity and cabinet width you just decoded are exactly what you need to size a replacement. A new system at the same tonnage and input will drop straight into the same duct and gas connections.
Related: Goodman vs Trane AC comparison · how to read any furnace data label · Goodman model number decoder.
Get your system replaced.
Tell us a little about your home and what you're replacing. A specialist will call you to work out exactly what you need, go over the price, and get it replaced. No obligation.