DoesTheMath

Rheem PROG40S-36N RH67 PV vs Ruud PRO+G40S-40N RH67 PD: which uses less energy?

At the medium draw pattern the Rheem PROG40S-36N RH67 PV and the Ruud PRO+G40S-40N RH67 PD use the same energy, 171 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
Figure Rheem PROG40S-36N RH67 PV Ruud PRO+G40S-40N RH67 PD
UEF (Uniform Energy Factor) 0.65 0.65
Energy use per year (therms) 171 171
First hour rating (gal) 66 69
Rated storage volume (gal) 39 39
Installed cost range $1,716–$2,950 $1,716–$2,950
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 Rheem PROG40S-36N RH67 PV if its price or availability suits you — on energy the two are level.
  • Pick the Ruud PRO+G40S-40N RH67 PD if you need more hot water in your busiest hour: it lists a first hour rating of 69 gallons against 66.
  • Neither if your household's busiest hour needs more than 69 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own