American GPDX-50L 3** vs Lochinvar GPCX-50L 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 Lochinvar GPCX-50L 1** uses 188 therms a year and the American GPDX-50L 3** 232 — 44 therms (19%) less, about 438 therms over ten years. Both are filed as a gas tank, 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 tank at the high draw pattern.
| Figure | American GPDX-50L 3** | Lochinvar GPCX-50L 1** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.73 | 0.9 (better) |
| Energy use per year (therms) | 232 | 188 (better) |
| First hour rating (gal) | 118 | 118 |
| Rated storage volume (gal) | 48 | 49 |
| Installed cost range NLR REMDB | $2,316–$4,484 | not published |
| ENERGY STAR certified ENERGY STAR | not matched | yes |
| On the market since ENERGY STAR | not filed | 2025-10-21 |
| 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 Lochinvar GPCX-50L 1** if running cost matters most: it uses 44 therms less a year on the same test.
- Pick the American GPDX-50L 3** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Lochinvar GPCX-50L 1**.
- Neither if your household's busiest hour needs more than 118 gallons of hot water — neither lists more. Check whether a 50-gallon heater is enough.
Each model on its own
- American GPDX-50L 3** 232 therms a year
- Lochinvar GPCX-50L 1** 188 therms a year