Ariston ENS40LUB 240V-3500W
Ariston ENS40LUB 240V-3500W 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 ENS40LUB 240V-3500W.
Certified figures
- Storage volume
- 36gallons
- UEF
- 0.92Uniform energy factor
- First-hour rating
- 39gallonsHot water in the first hour
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| Model number | Storage volume (gal) | UEF | First-hour rating (gal) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|---|
| ESB40S 240V-3500W* | 36 | 0.92 | 39 | 98% | Low |
UEF is the uniform energy factor. A dash means the model has no such figure.
It holds 36 gallons in the test, 4 gallons less than its 40-gallon sold size. Starting full, it gives 39 gallons of hot water in its first hour of use. Reheating lets it give 3 gallons beyond the 36 gallons in its tank. In the first hour, 457 of the 477 electric storage models give more hot water. The median electric storage model gives 55 gallons in its first hour.
In the test, 8% of its energy does not reach the hot water (UEF 0.92). Its test ran at the low level of daily hot water use. Of 157 electric storage models with the same draw pattern, 12 have a higher UEF. On its draw pattern, its UEF is also the median electric storage UEF. Of the energy spent to reheat water, 98% goes into it (its recovery efficiency).
There is one more basic model with the same test figures. The brand name on that one is AMERICAN STANDARD WATER HEATERS. For the full group, see the AMERICAN STANDARD WATER HEATERS ENS40LUB 240V-3500W page.
Also listed as
They carry every figure in the table above.
- Every Ariston basic model
- Every 40-gallon electric storage water heater
- Every electric storage water heater
Not covered
- Advertised figures. We have none on file for this model.