Ariston ENS50LU-*
Ariston ENS50LU-* is in the DOE listing as of Oct 19, 2026.
- Electric storage water heater
- 1 listed model
ENERGY STAR certification does not cover this type of water heater.
Its figures are also listed under AMERICAN STANDARD WATER HEATERS ENS50LU-*.
Certified figures
- Storage volume
- 42gallons
- UEF
- 0.93Uniform energy factor
- First-hour rating
- 52gallonsHot water in the first hour
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| Model number | Storage volume (gal) | UEF | First-hour rating (gal) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|---|
| ES50S* | 42 | 0.93 | 52 | 98% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
Starting full, it gives 52 gallons of hot water in its first hour of use. Its tank holds 42 gallons, so reheating adds 10 gallons during the first hour. In the first hour, 279 of the 477 electric storage models give more hot water. Among electric storage models, the median first-hour rating is 55 gallons.
In the test, 7% of its energy does not reach the hot water (UEF 0.93). Its test ran at the medium level of daily hot water use. Among 297 electric storage models on its draw pattern, 20 have a higher UEF. For its type and draw pattern, the median UEF is 0.92. When it reheats water in the test, 98% of the energy it uses ends up in the water.
Its test figures match those of 2 other basic models. Of those, one or more are under the AMERICAN STANDARD WATER HEATERS and Lennox brands. For the full group, see the AMERICAN STANDARD WATER HEATERS ENS50LU-*.
Also listed as
They carry every figure in the table above.
Not covered
- Advertised figures. We have none on file for this model.