Appliances / Heat pump water heaters / A. O. Smith
A. O. Smith HPTA-40 2 series
36 gal · 240-volt integrated heat pump water heater
Check the price at the store, then add $2,133 of electricity to get the true cost. We may earn a commission if you buy through these links; as an Amazon Associate we earn from qualifying purchases.
- Price. Check what it costs at the store.
- Plus running cost. Add $2,133 of electricity over 13 years. That is the part the price tag hides.
- Compare. Pick your state below, then check the cheaper-to-run models of the same size.
About the A. O. Smith HPTA-40 2 series
The A. O. Smith HPTA-40 2 series is a 36 gal 240-volt integrated heat pump water heater certified by ENERGY STAR. Its official test figure is 902 kWh of electricity a year, which at the U.S. average price of 18.19¢ per kWh comes to $164 a year, or $2,133 over a typical 13-year life.
For the same hot water, a standard electric tank water heater would use about 3,530 kWh a year, so this model uses 74% less electricity and saves about $478 a year.
Among 371 240-volt integrated models it ranks #129 for running cost. The cheapest model of this type would save $612 in electricity over 13 years, though it may differ in size and features.
If you want the same type and a similar size for less to run, the Friedrich PROH40 T2 FD400-15 uses 643 kWh a year and would save about $612 over 13 years.
Listed features: smart / app control.
Cost to run where you live
902 kWh a year (ENERGY STAR test figure) × 18.19¢ per kWh, the average residential price in the U.S. for Jan–Aug 2026 (EIA). Your bill depends on your utility and how you use it.
Cheaper to run, same type and size
Or see every under 50 gallons model ranked.
| Friedrich PROH40 T2 FD400-15 | 36 gal | $117/yr | saves $612 |
| Rheem PROPH40 T2 RH375-15 | 36 gal | $117/yr | saves $612 |
| Rheem PROPH40 T2 RH400-15 | 36 gal | $117/yr | saves $612 |
| Rheem XE40T10H22U0 | 36 gal | $117/yr | saves $612 |
Specs
| Brand | A. O. Smith |
| Model | HPTA-40 2** |
| Type | 240-volt integrated |
| Energy use | 902 kWh / year |
| Federal maximum for this type | 3530 kWh / year |
| Size | 36 gal |
| Width | 20 in |
| Features | Smart / app control |
| Tank size | 36 gal |
| First-hour rating | 55 gal |
| Efficiency (UEF) | 3.60 |
| Usage pattern | Medium-Usage |
| Voltage | 240 |
| Tank height | 66 in |
| Tank diameter | 20 in |
Specs and energy use from the ENERGY STAR certified products list (U.S. EPA). An asterisk in a model number stands for colour or finish codes. HouseholdLeak is not affiliated with ENERGY STAR or the EPA.
Questions people ask
How much does the A. O. Smith HPTA-40 2 series cost to run?
About $164 a year at the U.S. average electricity price (18.19¢/kWh), based on its ENERGY STAR rating of 902 kWh a year. In a state with expensive power it can be much more; pick your state on this page to see your number.
How much will the A. O. Smith HPTA-40 2 series cost in electricity over its life?
About $2,133 over 13 years, a typical life for a heat pump water heater. Add that to the price you pay to get the true cost to own.
Is the A. O. Smith HPTA-40 2 series energy efficient?
Yes. It is ENERGY STAR certified and uses 74% less electricity than a standard electric tank water heater.
Is there a cheaper water heater to run of the same type and size?
Yes. The Friedrich PROH40 T2 FD400-15 uses 643 kWh a year, about $612 less in electricity over 13 years.
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