DoesTheMath

RINNAI REHP50BM vs STATE HPACO-45 1**+AXST-50LBTTP 1**: which uses less energy?

At the medium draw pattern the RINNAI REHP50BM uses 866 kWh a year and the STATE HPACO-45 1**+AXST-50LBTTP 1** 915 — 49 kWh (5%) less, about 488 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 medium draw pattern.

Filed and computed figures
RINNAI REHP50BM STATE HPACO-45 1**+AXST-50LBTTP 1**
UEF (Uniform Energy Factor) 3.75 (better) 3.55
Energy use per year (kWh) 866 (better) 915
First hour rating (gal) 73 72
Rated storage volume (gal) 46 48
Installed cost range $3,057–$4,409 $3,099–$4,228
ENERGY STAR certified yes yes
Sound level (dB) 49 not filed
Refrigerant R-134a, GWP 1430 R-744 (CO2), GWP 1
On the market since 2024-04-01 2026-02-13
DOE CCD · 2026-09-19

What it costs to run

RINNAI REHP50BM: 866 kWh a year STATE HPACO-45 1**+AXST-50LBTTP 1**: 915 kWh a year

RINNAI REHP50BM — 866 kWh a year STATE HPACO-45 1**+AXST-50LBTTP 1** — 915 kWh a year

RINNAI REHP50BM is 49 kWh a year lower than STATE HPACO-45 1**+AXST-50LBTTP 1**.

DOE CCD · 2026-09-19

Report an issue with this number

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.
  • 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 RINNAI REHP50BM since 2024-04-01, the STATE HPACO-45 1**+AXST-50LBTTP 1** since 2026-02-13. A sale date, not a lifespan.

Which should you pick?

  • Pick the RINNAI REHP50BM if running cost matters most: it uses 49 kWh less a year on the same test.
  • Pick the STATE HPACO-45 1**+AXST-50LBTTP 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the RINNAI REHP50BM.
  • Neither if your household's busiest hour needs more than 73 gallons of hot water — neither lists more. Check whether a 50-gallon heater is enough.

Each model on its own

Analytics cookies

We count page views without cookies for everyone, and that counter is what we use to decide what to build. Google Analytics is separate: it uses cookies to record how a page was used, and it loads only if you allow it. Decline and the site works exactly the same. What we collect.