Rheem PROG40-40N RH62 vs Ruud PROG48-48U RH EC1: which uses less energy?
At the high draw pattern the Rheem PROG40-40N RH62 uses 256 therms a year and the Ruud PROG48-48U RH EC1 264 — 8 therms (3%) less, about 80 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.
| Figure | Rheem PROG40-40N RH62 | Ruud PROG48-48U RH EC1 |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.66 (better) | 0.64 |
| Energy use per year (therms) | 256 (better) | 264 |
| First hour rating (gal) | 84 | 88 |
| Rated storage volume (gal) | 38 | 46 |
| Installed cost range | $1,760–$3,064 | $1,761–$3,058 |
| ENERGY STAR certified | not matched | not matched |
What it costs to run
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 PROG40-40N RH62 if running cost matters most: it uses 8 therms less a year on the same test.
- Pick the Ruud PROG48-48U RH EC1 if you need more hot water in your busiest hour: it lists a first hour rating of 88 gallons against 84.
- Neither if your household's busiest hour needs more than 88 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
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Rheem PROG40-40N RH62
Its filed figures, class position and running cost on your ZIP.
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Ruud PROG48-48U RH EC1
Its filed figures, class position and running cost on your ZIP.