DoesTheMath

A. O. SMITH HPTS-66 2** vs LOCHINVAR HPTA-66 2**: which uses less energy?

At the high draw pattern the LOCHINVAR HPTA-66 2** uses 1,292 kWh a year and the A. O. SMITH HPTS-66 2** 1,341 — 49 kWh (4%) less, about 489 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
A. O. SMITH HPTS-66 2** LOCHINVAR HPTA-66 2**
UEF (Uniform Energy Factor) 3.7 3.84 (better)
Energy use per year (kWh) 1,341 1,292 (better)
First hour rating (gal) 82 83
Rated storage volume (gal) 67 68
Installed cost range $3,732–$4,558 $3,780–$4,707
ENERGY STAR certified yes yes
Refrigerant R-134a, GWP 1430 R-134a, GWP 1430
On the market since 2022-06-06 2024-03-01
DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH HPTS-66 2**: 1,341 kWh a year LOCHINVAR HPTA-66 2**: 1,292 kWh a year

A. O. SMITH HPTS-66 2** — 1,341 kWh a year LOCHINVAR HPTA-66 2** — 1,292 kWh a year

LOCHINVAR HPTA-66 2** is 49 kWh a year lower than A. O. SMITH HPTS-66 2**.

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 A. O. SMITH HPTS-66 2** since 2022-06-06, the LOCHINVAR HPTA-66 2** since 2024-03-01. A sale date, not a lifespan.

Which should you pick?

  • Pick the LOCHINVAR HPTA-66 2** if running cost matters most: it uses 49 kWh less a year on the same test.
  • Pick the A. O. SMITH HPTS-66 2** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the LOCHINVAR HPTA-66 2**.
  • Neither if your household's busiest hour needs more than 83 gallons of hot water — neither lists more. Check whether a 65-gallon heater is enough.

Each model on its own

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