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A. O. Smith HPTA-40 2**

A. O. Smith HPTA-40 2** 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 40 gallons, a certified storage volume of 36 gallons, a certified UEF of 3.60, and a certified first-hour rating of 55 gallons of hot water.

Its advertised UEF of 3.60 from A. O. Smith matches the certified 3.60 (Read Oct 4, 2026).

  • Heat pump water heater
  • 3 listed models
Storage volume
36gallons
UEF
3.60Uniform energy factor
First-hour rating
55gallonsHot water in the first hour
See it among every heat pump model

Advertised and certified figures

A. O. Smith HPTA-40 2**: advertised and certified
A. O. Smith HPTA-40 2**: advertised and certified Size: advertised 40 gal, certified 36 gal (advertised nominal size, certified storage volume). Size: advertised 37 gal, certified 36 gal (certified storage volume). UEF: advertised 3.60, certified 3.60. First-hour rating: advertised 55 gal, certified 55 gal. Size · advertised nominal size, certified storage volume Advertised 40 gal Certified 36 gal Size · certified storage volume Advertised 37 gal Certified 36 gal UEF Advertised 3.60 Certified 3.60 First-hour rating Advertised 55 gal Certified 55 gal
FigureAdvertisedCertifiedAdvertiserRead
Size 40 gal, nominal size 36 gal storage volume A. O. Smith Read Oct 4, 2026
Size 37 gal 36 gal storage volume A. O. Smith Read Oct 4, 2026
UEF 3.60 3.60 A. O. Smith Read Oct 4, 2026
First-hour rating 55 gal 55 gal A. O. Smith Read Oct 4, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
CAHP-40 2**363.6055426%Medium
HPA10-40H45DV 2**363.6055426%Medium
HPTA-40 2**363.6055426%Medium

UEF is the uniform energy factor. A dash means the model has no such figure.

ENERGY STAR certified models

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiency
CAHP-40 2**363.6055426%
HPA10-40H45DV 2**363.6055426%
HPTA-40 2**363.6055426%

It holds 36 gallons in the test, 4 gallons less than its 40-gallon sold size. It delivers 55 gallons of hot water in the test's first hour. That is 19 gallons more than its tank holds, since it reheats during the hour. Of 481 heat pump models, 418 give more hot water in the first hour. Among heat pump models, the median first-hour rating is 72 gallons.

It has 3 model numbers that are ENERGY STAR certified. In the test, it delivered 3.60 units of hot water energy for each unit used (its UEF). Pulling heat from the air lets its UEF pass 1. Its test simulated a day of medium hot water use (its draw pattern). Among 226 heat pump models on its draw pattern, 115 have a higher UEF. On its draw pattern, the median heat pump UEF is 3.68. While it reheats, the water gains 426% of the energy it uses (its recovery efficiency).

Its 3 model numbers are CAHP-40 2**, HPA10-40H45DV 2**, and HPTA-40 2**. All of its test figures are shared by 4 other basic models. Each of them is listed under a different brand.

It may qualify for 21 rebate programs. It may qualify for 7 more if it meets terms its figures do not show.

Also listed as

They carry every figure in the table above.

Rebates

ProgramStateStatusProgram page
Efficiency Arizona AZ May qualify Its own page
SRP Heat pump water heater rebate AZ May qualify Its own page
CleanPowerSF Electrify Your Home bill credits CA May qualify Its own page
Los Angeles Department of Water and Power Consumer Rebate Program CA May qualify Its own page
SMUD Heat pump water heater CA May qualify if it meets the other terms Its own page
SVCE Home Rebates CA May qualify if it meets the other terms Its own page
TECH Clean California HEEHRA Phase I CA May qualify Its own page
Colorado Springs Utilities Water heater rebate (heat pump) CO May qualify Its own page
DC Sustainable Energy Utility DCSEU Residential Heating & Cooling Rebates DC May qualify if it meets the other terms Its own page
Delaware Electric Cooperative Heat Pump Water Heating Rebate DE May qualify Its own page
Hawai‘i State Energy Office eHale Energy Saver Rebate Program HI May qualify Its own page
Idaho Power Hybrid Heat Pump Water Heater – Existing Homes ID May qualify Its own page
Ameren Illinois Instant Incentives IL May qualify Its own page
DTE Energy Water Heaters (heat pump) MI May qualify Its own page
Entergy Mississippi Residential Appliances Program MS May qualify Its own page
NC DEQ Energy Saver North Carolina NC May qualify Its own page
NHSaves Heat Pump Water Heater NH May qualify if it meets the other terms Its own page
PNM Home Energy Checkup Rebates NM May qualify Its own page
Energy Trust of Oregon OR May qualify Its own page
PECO Appliance Rebates PA May qualify Its own page
Rhode Island Energy Heat Pump Water Heater Rebate RI May qualify if it meets the other terms Its own page
TVA EnergyRight TN, AL, MS, KY, GA, NC, VA May qualify Its own page
Dominion Energy Virginia Water Energy Savings Program VA May qualify Its own page
Virginia Energy Home Energy Rebates VA May qualify if it meets the other terms Its own page
Puget Sound Energy Heat Pump Water Heater Rebate WA May qualify Its own page
Seattle City Light Heat Pump Water Heater Rebates WA May qualify Its own page
Focus on Energy (heat pump) WI May qualify if it meets the other terms Its own page
Focus on Energy Home Electrification and Appliance Rebates WI May qualify Its own page

Programs change their terms. Check the program's own page before you buy.

Updated Oct 26, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.