DoesTheMath

LOCHINVAR HPTU-66N 1** vs RELIANCE WATER HEATERS FPTU-66 1**: which uses less energy?

At the high draw pattern the LOCHINVAR HPTU-66N 1** uses 1,438 kWh a year and the RELIANCE WATER HEATERS FPTU-66 1** 1,451 — 13 kWh (1%) less, about 126 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.

Filed and computed figures
LOCHINVAR HPTU-66N 1** RELIANCE WATER HEATERS FPTU-66 1**
UEF (Uniform Energy Factor) 3.45 (better) 3.42
Energy use per year (kWh) 1,438 (better) 1,451
First hour rating (gal) 79 79
Rated storage volume (gal) 67 67
Installed cost range $3,703–$4,308 $3,699–$4,278
ENERGY STAR certified yes yes
Refrigerant R-134a, GWP 1430 R-134a, GWP 1430
On the market since 2019-04-05 2019-04-05
DOE CCD · 2026-09-19

What it costs to run

LOCHINVAR HPTU-66N 1**: 1,438 kWh a year RELIANCE WATER HEATERS FPTU-66 1**: 1,451 kWh a year

LOCHINVAR HPTU-66N 1** — 1,438 kWh a year RELIANCE WATER HEATERS FPTU-66 1** — 1,451 kWh a year

LOCHINVAR HPTU-66N 1** is 13 kWh a year lower than RELIANCE WATER HEATERS FPTU-66 1**.

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.
  • 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 LOCHINVAR HPTU-66N 1** since 2019-04-05, the RELIANCE WATER HEATERS FPTU-66 1** since 2019-04-05. A sale date, not a lifespan.

Which should you pick?

  • Pick the LOCHINVAR HPTU-66N 1** if running cost matters most: it uses 13 kWh less a year on the same test.
  • Pick the RELIANCE WATER HEATERS FPTU-66 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the LOCHINVAR HPTU-66N 1**.
  • Neither if your household's busiest hour needs more than 79 gallons of hot water — neither lists more. Check whether a 65-gallon heater is enough.

Each model on its own

Other comparisons

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