DoesTheMath

FRIEDRICH SCG40T03ST34U1 vs Lennox WHGS040T40NANS****: which uses less energy?

At the medium draw pattern the FRIEDRICH SCG40T03ST34U1 and the Lennox WHGS040T40NANS**** use the same energy, 188 therms a year each, on the same federal test. Both are filed as a gas tank, so the comparison holds; what separates them is below. Enter your ZIP to price either one on your own rate.

Side by side

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

Filed and computed figures
FRIEDRICH SCG40T03ST34U1 Lennox WHGS040T40NANS****
UEF (Uniform Energy Factor) 0.59 0.59
Energy use per year (therms) 188 188
First hour rating (gal) 67 68
Rated storage volume (gal) 38 38
Installed cost range $1,351–$2,012 $1,351–$2,012
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

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 FRIEDRICH SCG40T03ST34U1 if its price or availability suits you — on energy the two are level.
  • Pick the Lennox WHGS040T40NANS**** if you need more hot water in your busiest hour: it lists a first hour rating of 68 gallons against 67.
  • Neither if your household's busiest hour needs more than 68 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own

Other comparisons

Analytics cookies

We count page views without cookies for everyone, and that counter is what we use to decide what to build. Google Analytics is separate: it uses cookies to record how a page was used, and it loads only if you allow it. Decline and the site works exactly the same. What we collect.