American Standard ENS40L-* vs Rheem PROE38 S2 RH93 SB-LO: which uses less energy?
An asterisk in a model number stands for any character: one filing covers several variants.
At the low draw pattern the Rheem PROE38 S2 RH93 SB-LO uses 2,413 kWh a year and the American Standard ENS40L-* 2,439 — 26 kWh (1%) less, about 262 kWh over ten years. Both are filed as an electric tank, so the comparison holds. Enter your ZIP below to price the difference.
Side by side
Compared within one class only: models filed as an electric tank at the low draw pattern.
| Figure | American Standard ENS40L-* | Rheem PROE38 S2 RH93 SB-LO |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.92 | 0.93 (better) |
| Energy use per year (kWh) | 2,439 | 2,413 (better) |
| First hour rating (gal) | 46 | 42 |
| Rated storage volume (gal) | 36 | 35 |
| Installed cost range NLR REMDB | $1,591–$1,802 | $1,583–$1,994 |
| CPSC recall naming it CPSC | none on file | none on file |
DOE CCD · 2026-09-19 NLR REMDB · 2026-04-01 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 Rheem PROE38 S2 RH93 SB-LO if running cost matters most: it uses 26 kWh less a year on the same test.
- Pick the American Standard ENS40L-* if you need more hot water in your busiest hour: it lists a first hour rating of 46 gallons against 42.
- Neither if your household's busiest hour needs more than 46 gallons of hot water — neither lists more. Check whether a 30-gallon heater is enough.
Each model on its own
- American Standard ENS40L-* 2,439 kWh a year
- Rheem PROE38 S2 RH93 SB-LO 2,413 kWh a year