A. O. Smith ATHR-180M 1** vs Bradford White T9800 SE 199: which uses less energy?
An asterisk in a model number stands for any character: one filing covers several variants.
At the high draw pattern the A. O. Smith ATHR-180M 1** and the Bradford White T9800 SE 199 use the same energy, 178 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 high draw pattern.
| Figure | A. O. Smith ATHR-180M 1** | Bradford White T9800 SE 199 |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.95 | 0.95 |
| Energy use per year (therms) | 178 | 178 |
| Max flow (GPM) | 5.3 | 5.4 |
| Installed cost range NLR REMDB | $2,358–$3,405 | $2,358–$3,405 |
| ENERGY STAR certified ENERGY STAR | yes | yes |
| On the market since ENERGY STAR | 2024-02-01 | 2021-06-01 |
| CPSC recall naming it CPSC | none on file | none on file |
DOE CCD · 2026-09-19 NLR REMDB · 2026-04-01 ENERGY STAR · 2026-09-19 CPSC · 2026-09-24
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 above.
- No CPSC recall on file names either model (list checked 2026-09-24).
- Both are ENERGY STAR certified, which requires a manufacturer warranty of at least six years; the actual term for each model is not published.
- Time on the market, as filed with ENERGY STAR: the A. O. Smith ATHR-180M 1** since 2024-02-01, the Bradford White T9800 SE 199 since 2021-06-01. A sale date, not a lifespan.
Which should you pick?
- Pick the Bradford White T9800 SE 199 if you run more fixtures at once: it lists 5.4 GPM against 5.3.
- Neither if you need more than 5.4 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 ATHR-180M 1** 178 therms a year
- Bradford White T9800 SE 199 178 therms a year