waterheaterspecs

Heat pump · split system

A. O. Smith HPACO-45 1 with AXST tanks

The A. O. Smith HPACO-45 1 with AXST tanks line holds four certified rating sets of split system heat-pump water heaters, 59 model numbers sold under eight brand names, listed by A.O. Smith. Rated volume runs from 45 to 73 gal, and the first-hour rating runs from 67 to 95 gal. UEFs compare only within a draw pattern; the two high-draw sets rate UEF from 3.70 to 3.80. A. O. Smith HPACO-45 1+AXST-80 1, the set with the most model numbers, rates 0.08 below the median UEF of the 58 high-draw heat-pump sets (3.88).

Certified as of October 27, 2026 · EPA ENERGY STAR data, public domain · Compare in the Heater finder

Size by size

Certified values of A. O. Smith HPACO-45 1 with AXST tanks
Rating setRated volume, galFirst hour, galPer rated galUEFUEF rankkWh/yr
A. O. Smith HPACO-45 1+AXST-50T 114 model numbers45671.493.52 medium15th lowest of 38, two tied923
A. O. Smith HPACO-45 1+AXST-50LBTTP 19 model numbers48721.503.55 medium17th lowest of 38, three tied915
A. O. Smith HPACO-45 1+AXST-66 118 model numbers60821.373.70 high20th lowest of 58, two tied1,341
A. O. Smith HPACO-45 1+AXST-80 118 model numbers73951.303.80 high24th lowest of 58, three tied1,306

UEF ranks compare sets of the same draw pattern only.

A. O. Smith HPACO-45 1 with AXST tanks: first-hour rating against rated volume

A. O. Smith HPACO-45 1 with AXST tanksOther heat-pump sets

First-hour rating, gal

A. O. Smith HPACO-45 1 with AXST tanks: first-hour rating against rated volume40608010012014030405060708090100110120Rated volume, gal1×1.5×A. O. Smith CAHP-40 2A. O. Smith CAHP-50 2A. O. Smith CAHP-66 2A. O. Smith CAHP-80 2A. O. Smith FPTU-50 1A. O. Smith FPTU-66 1A. O. Smith FPTU-80 1A. O. Smith HP1050H45DV 1A. O. Smith HP1080H45DV 1A. O. Smith HPS10-50H45DV 2A. O. Smith HPS10-66H45DV 2A. O. Smith HPS10-80H45DV 2A. O. Smith HPTU-66CTA 1A. O. Smith HPTV-50 2A. O. Smith HPTV-66 2A. O. Smith HPTV-80 2American Standard ASHPWH-40American Standard ASHPWH-50American Standard ASHPWH-65American Standard ASHPWH-80Arctic Arctic-HP-Hot Water-KA06-50Arctic Arctic-HP-Hot Water-KA06-80Ariston ARIHPWH-40-TAriston ARIHPWH-50-TAriston ARIHPWH-65-TAriston ARIHPWH-80-TBradford White RE2H50S-Bradford White RE2H65T-Bradford White RE2H80T-Bradford White RE2HP50-1NCTTBradford White RE2HP65-1NCTTBradford White RE2HP80-1NCTTCarnot Labs N51Eco-Logical OMNI-50HP1-1AEco-Logical OMNI-50HP2-1AEco-Logical OMNI-80HP2-1AFriedrich PROH40 T2 FD310BMFriedrich PROH50 T2 FD310BMFriedrich PROH65 T2 FD310BMFriedrich PROH80 T2 FD310BMGE Profile PF40S10FPY01GE Profile PF50S10FPY01GE Profile PF65S10FPY01GE Profile PF80S10FPY01GE Profile PH40S10BPY01GE Profile PH50S10BNY01GE Profile PH50S10BPY01GE Profile PH65S10BNY01GE Profile PH65S10BPY01GE Profile PH80S10BNY01GE Profile PH80S10BPY01Giant GTHPCO-45 1+GTXST-50S 1Gree GRS-3.0Pd/TD50GANhA-DGree GRS-3.0Pd/TD70GANhA-DLG APHWC501DLG APHWC502DLG APHWC801DLG APHWC802DMidea CAN3-RSJ-15/190RDVN3-L3Midea CAN3-RSJ-15/190RDVN3-L4Midea CAN3-RSJ-15/250RDVN3-L3Midea CAN3-RSJ-15/250RDVN3-L4Midea CAN3-RSJ-15/300RDVN3-L3Midea CAN3-RSJ-15/300RDVN3-L4Navien NWP500S050AUMBNavien NWP500S065AUMBNavien NWP500S080AUMBReclaim Energy MP120F-RCReclaim Energy MP80F-RCRheem PROPH40 T0 RH120-MRheem PROPH40 T2 RH375-15Rheem PROPH40 T2 RH375-30Rheem PROPH50 T0 RH120Rheem PROPH50 T0 RH120-MRheem PROPH50 T2 RH375-15Rheem PROPH50 T2 RH375-30Rheem PROPH65 T0 RH120-MRheem PROPH65 T2 RH375-15Rheem PROPH65 T2 RH375-30Rheem PROPH80 T0 RH120-MRheem PROPH80 T2 RH375-15Rheem PROPH80 T2 RH375-30Rinnai REHP50Rinnai REHP80SanCO2 GS5-45HPC HP + ECO-119GLBKSanCO2 GS5-45HPC HP + ECO-43SSAQBSanCO2 GS5-45HPC HP + ECO-83SSAQBSmart Solar SSG2-ES 120Smart Solar SSG2-ES 65Smart Solar SSG2-ES 80Vaughn Thermal ME120HPTVaughn Thermal ME50HPTVaughn Thermal ME65HPTVaughn Thermal ME80HPTVaughn Thermal MP120FHPTVaughn Thermal MP55FHPTVaughn Thermal MP80FHPTA. O. Smith HPACO-45 1+AXST-66 1A. O. Smith HPACO-45 1+AXST-80 1A. O. Smith HPACO-45 1+AXST-50T 1A. O. Smith HPACO-45 1+AXST-50LBTTP 1
A. O. Smith HPACO-45 1 with AXST tanks: first-hour rating against rated volume406080100120140306090120Rated volume, galA. O. Smith CAHP-40 2A. O. Smith CAHP-50 2A. O. Smith CAHP-66 2A. O. Smith CAHP-80 2A. O. Smith FPTU-50 1A. O. Smith FPTU-66 1A. O. Smith FPTU-80 1A. O. Smith HP1050H45DV 1A. O. Smith HP1080H45DV 1A. O. Smith HPS10-50H45DV 2A. O. Smith HPS10-66H45DV 2A. O. Smith HPS10-80H45DV 2A. O. Smith HPTU-66CTA 1A. O. Smith HPTV-50 2A. O. Smith HPTV-66 2A. O. Smith HPTV-80 2American Standard ASHPWH-40American Standard ASHPWH-50American Standard ASHPWH-65American Standard ASHPWH-80Arctic Arctic-HP-Hot Water-KA06-50Arctic Arctic-HP-Hot Water-KA06-80Ariston ARIHPWH-40-TAriston ARIHPWH-50-TAriston ARIHPWH-65-TAriston ARIHPWH-80-TBradford White RE2H50S-Bradford White RE2H65T-Bradford White RE2H80T-Bradford White RE2HP50-1NCTTBradford White RE2HP65-1NCTTBradford White RE2HP80-1NCTTCarnot Labs N51Eco-Logical OMNI-50HP1-1AEco-Logical OMNI-50HP2-1AEco-Logical OMNI-80HP2-1AFriedrich PROH40 T2 FD310BMFriedrich PROH50 T2 FD310BMFriedrich PROH65 T2 FD310BMFriedrich PROH80 T2 FD310BMGE Profile PF40S10FPY01GE Profile PF50S10FPY01GE Profile PF65S10FPY01GE Profile PF80S10FPY01GE Profile PH40S10BPY01GE Profile PH50S10BNY01GE Profile PH50S10BPY01GE Profile PH65S10BNY01GE Profile PH65S10BPY01GE Profile PH80S10BNY01GE Profile PH80S10BPY01Giant GTHPCO-45 1+GTXST-50S 1Gree GRS-3.0Pd/TD50GANhA-DGree GRS-3.0Pd/TD70GANhA-DLG APHWC501DLG APHWC502DLG APHWC801DLG APHWC802DMidea CAN3-RSJ-15/190RDVN3-L3Midea CAN3-RSJ-15/190RDVN3-L4Midea CAN3-RSJ-15/250RDVN3-L3Midea CAN3-RSJ-15/250RDVN3-L4Midea CAN3-RSJ-15/300RDVN3-L3Midea CAN3-RSJ-15/300RDVN3-L4Navien NWP500S050AUMBNavien NWP500S065AUMBNavien NWP500S080AUMBReclaim Energy MP120F-RCReclaim Energy MP80F-RCRheem PROPH40 T0 RH120-MRheem PROPH40 T2 RH375-15Rheem PROPH40 T2 RH375-30Rheem PROPH50 T0 RH120Rheem PROPH50 T0 RH120-MRheem PROPH50 T2 RH375-15Rheem PROPH50 T2 RH375-30Rheem PROPH65 T0 RH120-MRheem PROPH65 T2 RH375-15Rheem PROPH65 T2 RH375-30Rheem PROPH80 T0 RH120-MRheem PROPH80 T2 RH375-15Rheem PROPH80 T2 RH375-30Rinnai REHP50Rinnai REHP80SanCO2 GS5-45HPC HP + ECO-119GLBKSanCO2 GS5-45HPC HP + ECO-43SSAQBSanCO2 GS5-45HPC HP + ECO-83SSAQBSmart Solar SSG2-ES 120Smart Solar SSG2-ES 65Smart Solar SSG2-ES 80Vaughn Thermal ME120HPTVaughn Thermal ME50HPTVaughn Thermal ME65HPTVaughn Thermal ME80HPTVaughn Thermal MP120FHPTVaughn Thermal MP55FHPTVaughn Thermal MP80FHPTA. O. Smith HPACO-45 1+AXST-66 1A. O. Smith HPACO-45 1+AXST-80 1A. O. Smith HPACO-45 1+AXST-50T 1A. O. Smith HPACO-45 1+AXST-50LBTTP 1
Filled: the four sets of A. O. Smith HPACO-45 1 with AXST tanks; open circles: the other 97 heat-pump sets. Dashed lines mark 1× and 1.5× the rated volume; the highest ratio in the line is 1.50×, on A. O. Smith HPACO-45 1+AXST-50LBTTP 1.

Across the sizes

From A. O. Smith HPACO-45 1+AXST-50T 1 to A. O. Smith HPACO-45 1+AXST-80 1, rated volume grows by 28 gal and the first-hour rating by 28 gal: 1.00 gal of first-hour output for each added rated gallon.

The sizes test at different draw patterns (two high and two medium), so UEF and annual energy compare only between sizes that share a pattern (why).

Strongest placings, size by size

MeasureValueMedian of the groupPlacingCompared with
Rated electricity useA. O. Smith HPACO-45 1+AXST-50T 1923 kWh/yr894 kWh/yr12th highest of 38, two tied38 medium-draw heat-pump sets
Rated volumeA. O. Smith HPACO-45 1+AXST-50T 145 gal61 gal13th lowest of 101, eight tied101 heat-pump sets
Rated electricity useA. O. Smith HPACO-45 1+AXST-50LBTTP 1915 kWh/yr894 kWh/yr14th highest of 38, three tied38 medium-draw heat-pump sets
First-hour output per rated gallonA. O. Smith HPACO-45 1+AXST-50LBTTP 11.501.2516th highest of 101, two tied101 heat-pump sets
Rated electricity useA. O. Smith HPACO-45 1+AXST-66 11,341 kWh/yr1,268 kWh/yr18th highest of 5858 high-draw heat-pump sets
UEFA. O. Smith HPACO-45 1+AXST-66 13.703.8820th lowest of 58, two tied58 high-draw heat-pump sets
First-hour ratingA. O. Smith HPACO-45 1+AXST-80 195 gal77 galtenth highest of 101, three tied101 heat-pump sets
Rated electricity useA. O. Smith HPACO-45 1+AXST-80 11,306 kWh/yr1,268 kWh/yr21st highest of 5858 high-draw heat-pump sets

Model numbers

The line covers 59 model numbers under eight brand names, first certified 2026-02-25 and most recently 2026-03-24. An asterisk stands for a variant character in the model number.

Model numberBrandRating setHeight × diameterElectricalRefrigerantConnectedCertified
HPACO-45 1**+AXST-50T 1**A. O. SmithHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45 1**+AXST-50TTTP 1**A. O. SmithHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45C 1**+AXST-50TC 1**A. O. SmithHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-03-19
HPACO-45C 1**+AXST-50TCTTP 1**A. O. SmithHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-03-19
MHPCO-45 1**+MXST-50T 1**AmericanHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
MHPCO-45 1**+MXST-50TTTP 1**AmericanHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
JWHPCO-45 1**+JWXST-50T 1**John WoodHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-03-19
JWHPCO-45 1**+JWXST-50TTTP 1**John WoodHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-03-19
LHPCO-45 1**+LXST-50T 1**LochinvarHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
LHPCO-45 1**+LXST-50TTTP 1**LochinvarHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-50T 1**RelianceHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-50TG 1**RelianceHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-50T 1**StateHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-50TG 1**StateHPACO-45 1+AXST-50T 157 × 16 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45 1**+AXST-50LBTTP 1**A. O. SmithHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45C 1**+AXST-50LBCTTP 1*A. O. SmithHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-03-24
MHPCO-45 1**+MXST-50LBTTP 1**AmericanHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-02-25
GHPCO-45 1**+GXST-50LBTTP 1**GSWHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-03-19
GTHPCO-45 1**+GTXST-50LBTTP 1*GiantHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-03-24
JWHPCO-45 1**+JWXST-50LBTTP 1*John WoodHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-03-24
LHPCO-45 1**+LXST-50LBTTP 1**LochinvarHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-50LBG 1**RelianceHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-50LBG 1**StateHPACO-45 1+AXST-50LBTTP 133 × 22.5 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45 1**+AXST-66 1**A. O. SmithHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45 1**+AXST-66TTP 1**A. O. SmithHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45C 1**+AXST-66C 1**A. O. SmithHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
HPACO-45C 1**+AXST-66CTTP 1**A. O. SmithHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
MHPCO-45 1**+MXST-66 1**AmericanHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
MHPCO-45 1**+MXST-66TTP 1**AmericanHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
GHPCO-45 1**+GXST-66 1**GSWHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
GHPCO-45 1**+GXST-66TTP 1**GSWHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
GTHPCO-45 1**+GTXST-66 1**GiantHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
GTHPCO-45 1**+GTXST-66TTP 1**GiantHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
JWHPCO-45 1**+JWXST-66 1**John WoodHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
JWHPCO-45 1**+JWXST-66TTP 1**John WoodHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-03-19
LHPCO-45 1**+LXST-66 1**LochinvarHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
LHPCO-45 1**+LXST-66TTP 1**LochinvarHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-66 1**RelianceHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-66G 1**RelianceHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-66 1**StateHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-66G 1**StateHPACO-45 1+AXST-66 159 × 18 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45 1**+AXST-80 1**A. O. SmithHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-24
HPACO-45 1**+AXST-80TTP 1**A. O. SmithHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
HPACO-45C 1**+AXST-80C 1**A. O. SmithHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
HPACO-45C 1**+AXST-80CTTP 1**A. O. SmithHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
MHPCO-45 1**+MXST-80 1**AmericanHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
MHPCO-45 1**+MXST-80TTP 1**AmericanHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
GHPCO-45 1**+GXST-80 1**GSWHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
GHPCO-45 1**+GXST-80TTP 1**GSWHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
GTHPCO-45 1**+GTXST-80 1**GiantHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
GTHPCO-45 1**+GTXST-80TTP 1**GiantHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
JWHPCO-45 1**+JWXST-80 1**John WoodHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
JWHPCO-45 1**+JWXST-80TTP 1**John WoodHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-03-19
LHPCO-45 1**+LXST-80 1**LochinvarHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
LHPCO-45 1**+LXST-80TTP 1**LochinvarHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-80 1**RelianceHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
RHPCO-45 1**+RXST-80G 1**RelianceHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-80 1**StateHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25
SHPCO-45 1**+SXST-80G 1**StateHPACO-45 1+AXST-80 158 × 20 in240 V / 20.2 AR-744yes2026-02-25

Nearest certified alternatives

Rating setFirst hourUEFRated volume
A. O. Smith HPS10-66H45DV 2compared with A. O. Smith HPACO-45 1+AXST-66 1same gal±0.00+7 gal
Bradford White RE2H65T-compared with A. O. Smith HPACO-45 1+AXST-66 1−3 gal−0.06+4 gal
A. O. Smith CAHP-66 2compared with A. O. Smith HPACO-45 1+AXST-66 1+1 gal+0.14+8 gal
Bradford White RE2H80T-compared with A. O. Smith HPACO-45 1+AXST-66 1+6 gal−0.11+15 gal
Reclaim Energy MP80F-RCcompared with A. O. Smith HPACO-45 1+AXST-80 1+3 gal±0.00+7 gal

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