DoesTheMath

RELIANCE WATER HEATERS ENL-40 1** vs Rheem XE38S06ST38U1: which uses less energy?

At the low draw pattern the Rheem XE38S06ST38U1 uses 2,466 kWh a year and the RELIANCE WATER HEATERS ENL-40 1** 2,522 — 55 kWh (2%) less, about 554 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
RELIANCE WATER HEATERS ENL-40 1** Rheem XE38S06ST38U1
UEF (Uniform Energy Factor) 0.89 0.91 (better)
Energy use per year (kWh) 2,522 2,466 (better)
First hour rating (gal) 50 49
Rated storage volume (gal) 35 35
Installed cost range not published not published
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

RELIANCE WATER HEATERS ENL-40 1**: 2,522 kWh a year Rheem XE38S06ST38U1: 2,466 kWh a year

RELIANCE WATER HEATERS ENL-40 1** — 2,522 kWh a year Rheem XE38S06ST38U1 — 2,466 kWh a year

Rheem XE38S06ST38U1 is 56 kWh a year lower than RELIANCE WATER HEATERS ENL-40 1**.

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 Rheem XE38S06ST38U1 if running cost matters most: it uses 55 kWh less a year on the same test.
  • Pick the RELIANCE WATER HEATERS ENL-40 1** if you need more hot water in your busiest hour: it lists a first hour rating of 50 gallons against 49.
  • Neither if your household's busiest hour needs more than 50 gallons of hot water — neither lists more. Check whether a 30-gallon heater is enough.

Each model on its own

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