American T-H3-OS-N 1** vs Stream 33 MGWH199IXNN: 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 American T-H3-OS-N 1** and the Stream 33 MGWH199IXNN 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 | American T-H3-OS-N 1** | Stream 33 MGWH199IXNN |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.95 | 0.95 |
| Energy use per year (therms) | 178 | 178 |
| Max flow (GPM) | 5.8 | 5.7 |
| Installed cost range NLR REMDB | $2,358–$3,405 | $2,358–$3,405 |
| ENERGY STAR certified ENERGY STAR | yes | not matched |
| On the market since ENERGY STAR | 2018-10-29 | not filed |
| 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).
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the American T-H3-OS-N 1** if you run more fixtures at once: it lists 5.8 GPM against 5.7.
- Neither if you need more than 5.8 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
- American T-H3-OS-N 1** 178 therms a year
- Stream 33 MGWH199IXNN 178 therms a year