DoesTheMath

A. O. SMITH GURT-50RL 4** vs Ruud PROP G50-50* RH HE EC3: which uses less energy?

At the high draw pattern the Ruud PROP G50-50* RH HE EC3 uses 192 therms a year and the A. O. SMITH GURT-50RL 4** 269 — 76 therms (28%) less, about 763 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 high draw pattern.

Filed and computed figures
A. O. SMITH GURT-50RL 4** Ruud PROP G50-50* RH HE EC3
UEF (Uniform Energy Factor) 0.63 0.88 (better)
Energy use per year (therms) 269 192 (better)
First hour rating (gal) 92 95
Rated storage volume (gal) 49 50
Installed cost range $1,747–$3,018 not published
ENERGY STAR certified not matched yes
On the market since not filed 2023-10-23
DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH GURT-50RL 4**: 269 therms a year Ruud PROP G50-50* RH HE EC3: 192 therms a year

A. O. SMITH GURT-50RL 4** — 269 therms a year Ruud PROP G50-50* RH HE EC3 — 192 therms a year

Ruud PROP G50-50* RH HE EC3 is 77 therms a year lower than A. O. SMITH GURT-50RL 4**.

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 Ruud PROP G50-50* RH HE EC3 if running cost matters most: it uses 76 therms less a year on the same test.
  • Pick the A. O. SMITH GURT-50RL 4** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Ruud PROP G50-50* RH HE EC3.
  • Neither if your household's busiest hour needs more than 95 gallons of hot water — neither lists more. Check whether a 50-gallon heater is enough.

Each model on its own

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