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GSW WATER HEATERS HPACO-45 1**+AXST-66 1**

GSW WATER HEATERS HPACO-45 1**+AXST-66 1** is in the DOE listing as of Oct 22, 2026. GSW WATER HEATERS HPACO-45 1**+AXST-66 1** is in the ENERGY STAR list as of Oct 22, 2026.

  • Heat pump water heater
  • 2 listed models

Its figures are also listed under A. O. Smith HPACO-45 1**+AXST-66 1**.

Storage volume
60gallons
UEF
3.70Uniform energy factor
First-hour rating
82gallonsHot water in the first hour
See it among every heat pump model

Product history

GSW WATER HEATERS HPACO-45 1**+AXST-66 1** was in the DOE listing by Oct 1, 2026.

GSW WATER HEATERS HPACO-45 1**+AXST-66 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 numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
GHPCO-45 1**+GXST-66 1**603.7082435%High
GHPCO-45 1**+GXST-66TTP 1**603.7082435%High

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
GHPCO-45 1**+GXST-66 1**603.7082435%
GHPCO-45 1**+GXST-66TTP 1**603.7082435%

It holds 60 gallons in the test, 6 gallons less than its 66-gallon sold size. Over one hour from a full tank, it gave 82 gallons in the test (its first-hour rating). Its tank holds 60 gallons, so reheating adds 22 gallons during the first hour. Among 481 heat pump models, 127 have a higher first-hour rating. The median heat pump model gives 72 gallons in the first hour of the test.

All 2 of its model numbers are ENERGY STAR certified. In the test, it gives 3.70 units of hot water energy per unit it uses (its UEF). Pulling heat from the air lets its UEF pass 1. Its test simulated a day of high hot water use (its draw pattern). Its UEF is lower than that of 145 of the 237 heat pump models with its draw pattern. On its draw pattern, the median heat pump UEF is 3.88. Its recovery efficiency is 435%, because it takes heat from the air as it reheats water.

Its 2 model numbers are GHPCO-45 1**+GXST-66 1** and GHPCO-45 1**+GXST-66TTP 1**. Its test figures match those of 7 other basic models. They are listed under 7 other brands, one each. For the full group, see the A. O. Smith HPACO-45 1**+AXST-66 1** page.

It may qualify for 17 rebate programs. It may qualify for 5 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
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
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
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
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
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 22, 2026 · Methodology

Not covered

  • Advertised figures. We have none on file for this model.