DoesTheMath

JOHN WOOD GCF-40 1** vs Rheem PROG40-40N RH67 PDV: which uses less energy?

At the medium draw pattern the JOHN WOOD GCF-40 1** uses 173 therms a year and the Rheem PROG40-40N RH67 PDV 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 JOHN WOOD GCF-40 1** Rheem PROG40-40N RH67 PDV
UEF (Uniform Energy Factor) 0.64 (better) 0.63
Energy use per year (therms) 173 (better) 176
First hour rating (gal) 70 67
Rated storage volume (gal) 38 38
Installed cost range $1,643–$2,763 $1,585–$2,613
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

JOHN WOOD GCF-40 1**: 173 therms a year Rheem PROG40-40N RH67 PDV: 176 therms a year

JOHN WOOD GCF-40 1** — 173 therms a year Rheem PROG40-40N RH67 PDV — 176 therms a year

JOHN WOOD GCF-40 1** is 3 therms a year lower than Rheem PROG40-40N RH67 PDV.

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 JOHN WOOD GCF-40 1** if running cost matters most: it uses 3 therms less a year on the same test.
  • Pick the Rheem PROG40-40N RH67 PDV if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the JOHN WOOD GCF-40 1**.
  • Neither if your household's busiest hour needs more than 70 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own