Lennox WHES040S45TD240S**** vs Lochinvar ENJ-40 1**: 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 Lennox WHES040S45TD240S**** and the Lochinvar ENJ-40 1** use the same energy, 3,493 kWh a year each, on the same federal test. Both are filed as an electric 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 an electric tank at the medium draw pattern.
| Figure | Lennox WHES040S45TD240S**** | Lochinvar ENJ-40 1** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.93 | 0.93 |
| Energy use per year (kWh) | 3,493 | 3,493 |
| First hour rating (gal) | 54 | 54 |
| Rated storage volume (gal) | 36 | 35 |
| Installed cost range NLR REMDB | $1,597–$2,019 | $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?
- Either one: On filed figures these are interchangeable; decide on installed price and availability.
- Neither if your household's busiest hour needs more than 54 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
- Lennox WHES040S45TD240S**** 3,493 kWh a year
- Lochinvar ENJ-40 1** 3,493 kWh a year