Trane Model Number Lookup
In a Trane model number the size is the three-digit group after the series, so 4TTR4036L1000A is 036, or 3 tons. Enter your model below to read it automatically. American Standard models work the same way.
Part of the model number tools. To find the age instead, use the Trane age lookup.
Model number size lookup
Where to find the Trane model number
On outdoor units the rating plate is on the side of the cabinet near the electrical panel; on furnaces it’s inside the blower compartment. The model line is labeled Model No. and typically starts with a digit and letters (4TTR4036L1000A) on outdoor units, or with letters (TUD2B080A9H31B, S9X1B080U4PSA) on furnaces.
Don’t confuse it with the serial: a Trane serial is 9 or 10 characters and gives the age.
Reading a Trane air conditioner or heat pump model
| Part | Example (4TTR4036L1000A) | Meaning |
|---|---|---|
| 1 | 4 | Commonly 4 for R-410A, 2 for older R-22 units |
| 2–4 | TTR | Series: TT = air conditioner, TW = heat pump |
| 5 | 4 | Series / generation digit |
| 6–8 | 036 | Nominal capacity in thousands of BTU/h |
| rest | L1000A | Voltage, design sequence and options |
American Standard uses the same structure with its own series letters, so 4A7A4030 is a 2.5-ton American Standard air conditioner.
| Model number | Size | Layout |
|---|---|---|
| 4TTR4 036 L1000A | 3 tons (36,000 BTU/h) | Voltage digit + series (3 characters) + generation digit + capacity (3 digits) |
| 4TWR5 048 | 4 tons (48,000 BTU/h) | Voltage digit + series (3 characters) + generation digit + capacity (3 digits) |
| 2TTB3 018 A1000A | 1.5 tons (18,000 BTU/h) | Voltage digit + series (3 characters) + generation digit + capacity (3 digits) |
| 4A7A4 030 | 2.5 tons (30,000 BTU/h) | Voltage digit + series (3 characters) + generation digit + capacity (3 digits) |
| 4A6H6 060 | 5 tons (60,000 BTU/h) | Voltage digit + series (3 characters) + generation digit + capacity (3 digits) |
| TTA 036 C100A0 | 3 tons (36,000 BTU/h) | Series (3 letters) + capacity (3 digits) |
The newest Trane variable-speed and communicating models keep the size in the same place (for example 4TTV0036).
Reading a Trane furnace model
Trane and American Standard furnace models put a three-digit input rating in thousands of BTU/h after the series and a letter:
| Model number | Size | Layout |
|---|---|---|
| TUD2B 080 A9H31B | 80,000 BTU/h input (furnace) | Series + input in thousands of BTU (3 digits) |
| S9X1B 080 U4PSA | 80,000 BTU/h input (furnace) | Series + input in thousands of BTU (3 digits) |
| TUH1B 060 A9361A | 60,000 BTU/h input (furnace) | Series + input in thousands of BTU (3 digits) |
| S8X1B 040 M2PSA | 40,000 BTU/h input (furnace) | Series + input in thousands of BTU (3 digits) |
Input is the fuel burned per hour. A 96% furnace with an 080 code delivers roughly 77,000 BTU/h of heat; an 80% furnace with the same code, about 64,000.
Sizes you’ll see
| Code | BTU/h | Tons |
|---|---|---|
| 018 | 18,000 | 1.5 |
| 024 | 24,000 | 2 |
| 030 | 30,000 | 2.5 |
| 036 | 36,000 | 3 |
| 042 | 42,000 | 3.5 |
| 048 | 48,000 | 4 |
| 060 | 60,000 | 5 |
Residential split systems stop at 5 tons. Larger homes use two or more systems.
When the size is useful
- Replacing a unit: start from the existing size, but ask for a load calculation. Older homes that have had insulation or window upgrades often need less capacity than the original system.
- Matching the indoor coil: the coil (often a Trane
4TXC-style model) has its own capacity code and should match the outdoor unit. - Checking a quote: if a contractor proposes a different size than you have, the model numbers make it easy to compare.
Frequently asked questions
How do I read the tonnage on a Trane model number?
Find the three-digit group that starts with 0 after the first five characters, such as 036 in 4TTR4036L1000A. It's the capacity in thousands of BTU per hour. 036 is 36,000 BTU/h, which is 3 tons.
What does TT and TW mean in a Trane model?
TT models are air conditioners and TW models are heat pumps. For example, 4TTR is an AC series and 4TWR a heat pump series.
What does the first digit of a Trane model number mean?
On outdoor units it's commonly 2 on older R-22 equipment and 4 on R-410A equipment, so it's a quick clue to the refrigerant. Confirm on the rating plate, which lists the refrigerant.
How do I find the BTU of a Trane furnace?
Look for the three digits between letters in the middle of the model, like 080 in TUD2B080A9H31B or S9X1B080U4PSA. That's 80,000 BTU/h input.
Does the Trane model number show the age?
No. The age is in the serial number. Use our Trane serial number lookup for the date.