American Standard GSN40L2-3-* vs Lennox WHGS040T40NAXS****: which uses less energy?
An asterisk in a model number stands for any character: one filing covers several variants.
At the medium draw pattern the American Standard GSN40L2-3-* and the Lennox WHGS040T40NAXS**** use the same energy, 185 therms a year each, on the same federal test. Both are filed as a gas tank, 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 tank at the medium draw pattern.
| Figure | American Standard GSN40L2-3-* | Lennox WHGS040T40NAXS**** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.6 | 0.6 |
| Energy use per year (therms) | 185 | 185 |
| First hour rating (gal) | 64 | 74 |
| Rated storage volume (gal) | 38 | 38 |
| Installed cost range NLR REMDB | $1,410–$2,162 | $1,410–$2,162 |
| CPSC recall naming it CPSC | recall 16171 | none on file (better) |
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.
- The American Standard GSN40L2-3-* is named in CPSC recall 16171; see the recall page for which units and the remedy.
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the Lennox WHGS040T40NAXS**** if you need more hot water in your busiest hour: it lists a first hour rating of 74 gallons against 64.
- Neither if your household's busiest hour needs more than 74 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
- American Standard GSN40L2-3-* 185 therms a year
- Lennox WHGS040T40NAXS**** 185 therms a year