DoesTheMath

AMERICAN STANDARD WATER HEATERS ENS30LU-* vs ARISTON ENS30LUB*: which uses less energy?

At the low draw pattern the AMERICAN STANDARD WATER HEATERS ENS30LU-* uses 2,413 kWh a year and the ARISTON ENS30LUB* 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.

Filed and computed figures
AMERICAN STANDARD WATER HEATERS ENS30LU-* ARISTON ENS30LUB*
UEF (Uniform Energy Factor) 0.93 (better) 0.92
Energy use per year (kWh) 2,413 (better) 2,439
First hour rating (gal) 40 40
Rated storage volume (gal) 27 28
Installed cost range $1,467–$1,793 $1,475–$1,602
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

AMERICAN STANDARD WATER HEATERS ENS30LU-*: 2,413 kWh a year ARISTON ENS30LUB*: 2,439 kWh a year

AMERICAN STANDARD WATER HEATERS ENS30LU-* — 2,413 kWh a year ARISTON ENS30LUB* — 2,439 kWh a year

AMERICAN STANDARD WATER HEATERS ENS30LU-* is 26 kWh a year lower than ARISTON ENS30LUB*.

DOE CCD · 2026-09-19

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Enter your ZIP to price both units on the same rate where you live.

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 below.
  • The actual warranty term is printed in each model’s documentation, not in any registry.

Which should you pick?

  • Pick the AMERICAN STANDARD WATER HEATERS ENS30LU-* if running cost matters most: it uses 26 kWh less a year on the same test.
  • Pick the ARISTON ENS30LUB* if the installed price matters more than the running cost: its modeled installed range is $1,475–$1,602 against $1,467–$1,793.
  • Neither if your household's busiest hour needs more than 40 gallons of hot water — neither lists more. Check whether a 30-gallon heater is enough.

Each model on its own

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