A. O. SMITH TK-110U-E 2** vs STATE ATI-140B-N 1**: which uses less energy?
At the medium draw pattern the A. O. SMITH TK-110U-E 2** and the STATE ATI-140B-N 1** use the same energy, 137 therms a year each, on the same federal test. Both are filed as a gas tankless unit, so the comparison holds; what separates them is below. Enter your ZIP to price either one on your own rate.
Side by side
Compared within one class only: models filed as a gas tankless unit at the medium draw pattern.
| Figure | A. O. SMITH TK-110U-E 2** | STATE ATI-140B-N 1** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.81 | 0.81 |
| Energy use per year (therms) | 137 | 137 |
| Max flow (GPM) | 3.5 | 3.6 |
| Installed cost range | $1,698–$2,632 | $1,698–$2,632 |
| ENERGY STAR certified | not matched | not matched |
What it costs to run
Reliability
Not published: Reliability, failure rates and each model’s actual warranty term.
The registries these figures come from certify energy performance under a federal test; none of them records how long a unit lasts or how often it fails, so this page does not rank the two on reliability.
What is here instead:
- The filed efficiency, capacity and tank size of both models, side by side below.
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the A. O. SMITH TK-110U-E 2** if its price or availability suits you — on energy the two are level.
- Pick the STATE ATI-140B-N 1** if you run more fixtures at once: it lists 3.6 GPM against 3.5.
- Neither if you need more than 3.6 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
-
A. O. SMITH TK-110U-E 2**
Its filed figures, class position and running cost on your ZIP.
-
STATE ATI-140B-N 1**
Its filed figures, class position and running cost on your ZIP.