GSW ATM-199M-N 1** vs Vesta VTP-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 Vesta VTP-199 uses 176 therms a year and the GSW ATM-199M-N 1** 178 — 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 | GSW ATM-199M-N 1** | Vesta VTP-199 |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.95 | 0.96 (better) |
| Energy use per year (therms) | 178 | 176 (better) |
| Max flow (GPM) | 6 | 6 |
| Installed cost range NLR REMDB | $2,358–$3,405 | $2,405–$3,460 |
| ENERGY STAR certified ENERGY STAR | yes | yes |
| On the market since ENERGY STAR | 2025-05-15 | 2023-10-16 |
| CPSC recall naming it CPSC | none on file (better) | recall 26026 |
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.
- The Vesta VTP-199 is named in CPSC recall 26026; see the recall page for which units and the remedy.
- 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 GSW ATM-199M-N 1** since 2025-05-15, the Vesta VTP-199 since 2023-10-16. A sale date, not a lifespan.
Which should you pick?
- Pick the Vesta VTP-199 if running cost matters most: it uses 2 therms less a year on the same test.
- Pick the GSW ATM-199M-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 Vesta VTP-199.
- Neither if you need more than 6 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
- GSW ATM-199M-N 1** 178 therms a year
- Vesta VTP-199 176 therms a year