DoesTheMath

GE GG40S**AYV01 vs Lennox WHGS040S40NPXS****: which uses less energy?

At the medium draw pattern the Lennox WHGS040S40NPXS**** uses 173 therms a year and the GE GG40S**AYV01 176 — 3 therms (2%) less, about 27 therms over ten years. Both are filed as a gas tank, so the comparison holds. Enter your ZIP below to price the difference.


Side by side

Compared within one class only: models filed as a gas tank at the medium draw pattern.

Filed and computed figures
Figure GE GG40S**AYV01 Lennox WHGS040S40NPXS****
UEF (Uniform Energy Factor) 0.63 0.64 (better)
Energy use per year (therms) 176 173 (better)
First hour rating (gal) 72 71
Rated storage volume (gal) 40 39
Installed cost range $1,614–$2,687 $1,658–$2,800
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

GE GG40S**AYV01: 176 therms a year Lennox WHGS040S40NPXS****: 173 therms a year

GE GG40S**AYV01 — 176 therms a year Lennox WHGS040S40NPXS**** — 173 therms a year

Lennox WHGS040S40NPXS**** is 3 therms a year lower than GE GG40S**AYV01.

DOE CCD · 2026-09-19

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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 WHGS040S40NPXS**** if running cost matters most: it uses 3 therms less a year on the same test.
  • Pick the GE GG40S**AYV01 if you need more hot water in your busiest hour: it lists a first hour rating of 72 gallons against 71.
  • Neither if your household's busiest hour needs more than 72 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own