A. O. Smith ATI-140B-N 1**
A. O. Smith ATI-140B-N 1** is in the DOE listing as of Oct 26, 2026.
It has a certified UEF of 0.81 and a certified flow of 3.6 gal/min at a 67°F rise.
Its certified flow is 3.6 gal/min at a 67°F rise, while A. O. Smith advertises 7.7 gal/min, no rise stated (Read Oct 4, 2026), so a comparison at the same rise is not possible.
- Gas tankless water heater
- 3 listed models
Not listed as ENERGY STAR certified on Oct 26, 2026.
Certified and advertised figures
- Flow at a 67°F rise
- 3.6gallons per minuteCertified
- Advertised flow
- 7.7gallons per minuteA. O. Smith, no rise stated
- UEF
- 0.81Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
A bigger rise from colder incoming water leaves the heater with less flow.
- Cold water
- Cold water must be at least 10°F colder than the hot water setting.
- Flow estimate
- The estimate uses the lowest certified flow among the listed models. It is about 3.4 gal/min at a 70°F rise.
Flow limits
- The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
- Cold water from a well or long pipe run can differ from the temperature you enter.
- Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.
Advertised and certified figures
| Figure | Advertised | Certified | Advertiser | Read |
|---|---|---|---|---|
| UEF | 0.82 | 0.81 | A. O. Smith | Read Oct 4, 2026 |
| UEF | 0.81 | 0.81 | A. O. Smith | Read Oct 4, 2026 |
| Flow | 7.7 gal/min, no rise stated | 3.6 gal/min at a 67°F rise | A. O. Smith | Read Oct 4, 2026 |
| Flow | 3.6 gal/min at a 67°F rise | 3.6 gal/min at a 67°F rise | A. O. Smith | Read Oct 4, 2026 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| ATI-140B-N 1** | 0.81 | 3.6 | 84% | Medium |
| ATI-140X3-N 1** | 0.81 | 3.6 | 84% | Medium |
| GT12I-140B-N | 0.81 | 3.6 | 84% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
At a 67°F rise, its flow in the test is 3.6 gallons per minute. The median gas tankless model heats 4.8 gallons per minute by 67°F. Its flow at a 67°F rise trails 409 of the 487 gas tankless models.
It was not listed as ENERGY STAR certified on Oct 26, 2026. In tests, 81% of the energy went to hot water, so its UEF is 0.81. The daily hot water use in the test, called its draw pattern, was medium. Of 77 gas tankless models with the same draw pattern, 48 have a higher UEF. On its draw pattern, the median gas tankless UEF is 0.82. Of the energy it spends heating water, 84% ends up in it (its recovery efficiency).
It is sold as ATI-140B-N 1**, ATI-140X3-N 1**, and GT12I-140B-N. Its test figures match those of 10 other basic models. Besides this brand, 4 brands list one or more of them.
Also listed as
They carry every figure in the table above.
- Every A. O. Smith basic model
- Every gas tankless water heater certified below 4.0 gallons per minute
- Every gas tankless water heater
- The most-searched gas tankless models side by side
Not covered
- Changes to an advertised figure after the date beside it.