NAVIEN NWP500S080AUMB vs Rheem PROPH80 T2 RH400-30: which uses less energy?
At the high draw pattern the Rheem PROPH80 T2 RH400-30 uses 1,219 kWh a year and the NAVIEN NWP500S080AUMB 1,225 — 6 kWh (0%) less, about 60 kWh over ten years. Both are filed as an electric tank, so the comparison holds. Enter your ZIP below to price the difference.
Side by side
Compared within one class only: models filed as an electric tank at the high draw pattern.
| Figure | NAVIEN NWP500S080AUMB | Rheem PROPH80 T2 RH400-30 |
|---|---|---|
| UEF (Uniform Energy Factor) | 4.05 | 4.07 (better) |
| Energy use per year (kWh) | 1,225 | 1,219 (better) |
| First hour rating (gal) | 85 | 87 |
| Rated storage volume (gal) | 74 | 72 |
| Installed cost range | $3,999–$4,974 | $3,936–$4,975 |
| ENERGY STAR certified | yes | yes |
| Refrigerant | R-134a, GWP 1430 | R-134a, GWP 1430 |
| On the market since | 2025-04-30 | 2024-06-24 |
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.
- Both are ENERGY STAR certified, which requires a manufacturer warranty of at least six years; the actual term for each model is not published.
- Time on the market, as filed with ENERGY STAR: the NAVIEN NWP500S080AUMB since 2025-04-30, the Rheem PROPH80 T2 RH400-30 since 2024-06-24. A sale date, not a lifespan.
Which should you pick?
- Pick the Rheem PROPH80 T2 RH400-30 if running cost matters most: it uses 6 kWh less a year on the same test.
- Pick the NAVIEN NWP500S080AUMB if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Rheem PROPH80 T2 RH400-30.
- Neither if your household's busiest hour needs more than 87 gallons of hot water — neither lists more. Check whether a 75-gallon heater is enough.
Each model on its own
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NAVIEN NWP500S080AUMB
Its filed figures, class position and running cost on your ZIP.
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Rheem PROPH80 T2 RH400-30
Its filed figures, class position and running cost on your ZIP.