DoesTheMath

JETGLAS RE240S*-***** vs Lennox WHES040L45TN240B****: which uses less energy?

At the low draw pattern the Lennox WHES040L45TN240B**** uses 2,439 kWh a year and the JETGLAS RE240S*-***** 2,466 — 27 kWh (1%) less, about 268 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
JETGLAS RE240S*-***** Lennox WHES040L45TN240B****
UEF (Uniform Energy Factor) 0.91 0.92 (better)
Energy use per year (kWh) 2,466 2,439 (better)
First hour rating (gal) 48 50
Rated storage volume (gal) 36 36
Installed cost range not published $1,591–$1,802
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

JETGLAS RE240S*-*****: 2,466 kWh a year Lennox WHES040L45TN240B****: 2,439 kWh a year

JETGLAS RE240S*-***** — 2,466 kWh a year Lennox WHES040L45TN240B**** — 2,439 kWh a year

Lennox WHES040L45TN240B**** is 27 kWh a year lower than JETGLAS RE240S*-*****.

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 Lennox WHES040L45TN240B**** if running cost matters most: it uses 27 kWh less a year on the same test.
  • Pick the JETGLAS RE240S*-***** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Lennox WHES040L45TN240B****.
  • Neither if your household's busiest hour needs more than 50 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own

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