A. O. Smith HPACO-45 1**+AXST-50T 1**
A. O. Smith HPACO-45 1**+AXST-50T 1** is in the DOE listing as of Oct 26, 2026 and is in the ENERGY STAR list as of Oct 26, 2026.
It has a labeled size of 45 gallons, a certified storage volume of 45 gallons, a certified UEF of 3.52, and a certified first-hour rating of 67 gallons of hot water.
- Heat pump water heater
- 4 listed models
Certified figures
- Storage volume
- 45gallons
- UEF
- 3.52Uniform energy factor
- First-hour rating
- 67gallonsHot water in the first hour
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Change your hourProduct history
A. O. Smith HPACO-45 1**+AXST-50T 1** was in the DOE listing by Oct 1, 2026.
A. O. Smith HPACO-45 1**+AXST-50T 1** has a recorded ENERGY STAR market-availability date of Feb 13, 2026. It first appeared in the ENERGY STAR list between February 2026 and August 2026.
Certified figures by listed model
| Model number | Storage volume (gal) | UEF | First-hour rating (gal) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|---|
| HPACO-45 1**+AXST-50T 1** | 45 | 3.52 | 67 | 413% | Medium |
| HPACO-45 1**+AXST-50TTTP 1** | 45 | 3.52 | 67 | 413% | Medium |
| HPACO-45C 1**+AXST-50TC 1** | 45 | 3.52 | 67 | 413% | Medium |
| HPACO-45C 1**+AXST-50TCTTP 1** | 45 | 3.52 | 67 | 413% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
ENERGY STAR certified models
| Model number | Storage volume (gal) | UEF | First-hour rating (gal) | Recovery efficiency |
|---|---|---|---|---|
| HPACO-45 1**+AXST-50T 1** | 45 | 3.52 | 67 | 413% |
| HPACO-45 1**+AXST-50TTTP 1** | 45 | 3.52 | 67 | 413% |
| HPACO-45C 1**+AXST-50TC 1** | 45 | 3.52 | 67 | 413% |
| HPACO-45C 1**+AXST-50TCTTP 1** | 45 | 3.52 | 67 | 413% |
Sold as 45 gallons, it holds 45 gallons in the test. Over one hour from a full tank, it gave 67 gallons in the test (its first-hour rating). That is 22 gallons more than its tank holds, since it reheats during the hour. In the first hour, 287 of the 481 heat pump models give more hot water. Among heat pump models, the median first-hour rating is 72 gallons.
Under this basic model, 4 model numbers are ENERGY STAR certified. In the test, it delivered 3.52 units of hot water energy for each unit used (its UEF). Pulling heat from the air lets its UEF pass 1. The daily hot water use in the test, called its draw pattern, was medium. Of 226 heat pump models with the same draw pattern, 143 have a higher UEF and 68 a lower one. For its type and draw pattern, the median UEF is 3.68. While it reheats, the water gains 413% of the energy it uses (its recovery efficiency).
All 4 of its model numbers carry the same certified figures. All of its test figures are shared by 5 other basic models. They are listed under 5 other brands, one each.
It may qualify for 17 rebate programs. Another 5 rebate programs may accept it if it meets their other terms.
Also listed as
They carry every figure in the table above.
Rebates
Programs change their terms. Check the program's own page before you buy.
- Every A. O. Smith basic model
- Every 40-gallon heat pump water heater
- Every heat pump water heater
- The most-searched heat pump models side by side
Not covered
- Advertised figures. We have none on file for this model.