A. O. Smith T-H3J-OS-N 1** vs Takagi T-H3J-DV-N 1**: 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 T-H3J-OS-N 1** uses 178 therms a year and the Takagi T-H3J-DV-N 1** 180 — 2 therms (1%) less, about 19 therms over ten years. Both are filed as a gas tankless unit, so the comparison holds. Enter your ZIP below to price the difference.
Side by side
Compared within one class only: models filed as a gas tankless unit at the high draw pattern.
| Figure | A. O. Smith T-H3J-OS-N 1** | Takagi T-H3J-DV-N 1** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.95 (better) | 0.94 |
| Energy use per year (therms) | 178 (better) | 180 |
| Max flow (GPM) | 4.7 | 4.7 |
| Installed cost range NLR REMDB | $2,358–$3,405 | $2,311–$3,350 |
| ENERGY STAR certified ENERGY STAR | yes | not matched |
| On the market since ENERGY STAR | 2012-08-01 | 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 A. O. Smith T-H3J-OS-N 1** if running cost matters most: it uses 2 therms less a year on the same test.
- Pick the Takagi T-H3J-DV-N 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the A. O. Smith T-H3J-OS-N 1**.
- Neither if you need more than 4.7 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 T-H3J-OS-N 1** 178 therms a year
- Takagi T-H3J-DV-N 1** 180 therms a year