waterheaterspecs

Heat pump · 240 V integrated

A. O. Smith CAHP-xx 2

The A. O. Smith CAHP-xx 2 line holds four certified rating sets of 240 V integrated heat-pump water heaters, 36 model numbers sold under five brand names, listed by A.O. Smith. Rated volume runs from 36 to 81 gal, and the first-hour rating runs from 55 to 95 gal. UEFs compare only within a draw pattern; the two high-draw sets rate UEF from 3.84 to 3.88. A. O. Smith CAHP-80 2 sits exactly on 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 CAHP-xx 2
Rating setRated volume, galFirst hour, galPer rated galUEFUEF rankkWh/yr
A. O. Smith CAHP-40 29 model numbers36551.533.60 medium18th highest of 38902
A. O. Smith CAHP-50 29 model numbers46651.413.68 medium17th highest of 38883
A. O. Smith CAHP-66 29 model numbers68831.223.84 high27th lowest of 581,292
A. O. Smith CAHP-80 29 model numbers81951.173.88 high29th highest of 58, two tied1,279

UEF ranks compare sets of the same draw pattern only.

A. O. Smith CAHP-xx 2: first-hour rating against rated volume

A. O. Smith CAHP-xx 2Other heat-pump sets

First-hour rating, gal

A. O. Smith CAHP-xx 2: first-hour rating against rated volume40608010012014030405060708090100110120Rated volume, gal1×1.5×A. 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 HPACO-45 1+AXST-50LBTTP 1A. O. Smith HPACO-45 1+AXST-50T 1A. O. Smith HPACO-45 1+AXST-66 1A. O. Smith HPACO-45 1+AXST-80 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 CAHP-40 2A. O. Smith CAHP-50 2A. O. Smith CAHP-66 2A. O. Smith CAHP-80 2
A. O. Smith CAHP-xx 2: first-hour rating against rated volume406080100120140306090120Rated volume, galA. 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 HPACO-45 1+AXST-50LBTTP 1A. O. Smith HPACO-45 1+AXST-50T 1A. O. Smith HPACO-45 1+AXST-66 1A. O. Smith HPACO-45 1+AXST-80 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 CAHP-40 2A. O. Smith CAHP-50 2A. O. Smith CAHP-66 2A. O. Smith CAHP-80 2
Filled: the four sets of A. O. Smith CAHP-xx 2; 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 1.53×, on A. O. Smith CAHP-40 2.

Across the sizes

From A. O. Smith CAHP-40 2 to A. O. Smith CAHP-80 2, rated volume grows by 45 gal and the first-hour rating by 40 gal: 0.89 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 volumeA. O. Smith CAHP-40 236 gal61 gallowest of 101, five tied101 heat-pump sets
First-hour ratingA. O. Smith CAHP-40 255 gal77 galtenth lowest of 101, three tied101 heat-pump sets
UEFA. O. Smith CAHP-50 23.683.5617th highest of 3838 medium-draw heat-pump sets
Rated electricity useA. O. Smith CAHP-50 2883 kWh/yr894 kWh/yr18th lowest of 3838 medium-draw heat-pump sets
Compressor cut-offA. O. Smith CAHP-66 237 °F36.3 °F19th highest of 90, 27 tied90 heat-pump sets that report one
Rated electricity useA. O. Smith CAHP-66 21,292 kWh/yr1,268 kWh/yr24th highest of 5858 high-draw heat-pump sets
First-hour ratingA. O. Smith CAHP-80 295 gal77 galtenth highest of 101, three tied101 heat-pump sets
Rated volumeA. O. Smith CAHP-80 281 gal61 gal11th highest of 101101 heat-pump sets

Model numbers

The line covers 36 model numbers under five brand names, first certified 2025-12-12 and most recently 2026-08-13. An asterisk stands for a variant character in the model number.

Model numberBrandRating setHeight × diameterElectricalRefrigerantConnectedCertified
CAHP-40 2**A. O. SmithCAHP-40 266 × 20 in240 V / 22 AR-134ayes2026-08-13
HPA10-40H45DV 2**A. O. SmithCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
HPTA-40 2**A. O. SmithCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
HPA10240H045DV 2**AmericanCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
CHPA-40 2**LochinvarCAHP-40 266 × 20 in240 V / 22 AR-134ayes2026-08-13
HPPA040KD 2**LochinvarCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
10-40-DHPTA 2**RelianceCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
CSHP-40 2**StateCAHP-40 266 × 20 in240 V / 22 AR-134ayes2026-08-13
HPAX-40-DHPT 2**StateCAHP-40 266 × 20 in240 V / 22 AR-134ayes2025-12-12
CAHP-50 2**A. O. SmithCAHP-50 263 × 15 in240 V / 22 AR-134ayes2026-08-13
HPA10-50H45DV 2**A. O. SmithCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
HPTA-50 2**A. O. SmithCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
HPA10250H045DV 2**AmericanCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
CHPA-50 2**LochinvarCAHP-50 263 × 15 in240 V / 22 AR-134ayes2026-08-13
HPPA050KD 2**LochinvarCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
10-50-DHPTA 2**RelianceCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
CSHP-50 2**StateCAHP-50 263 × 15 in240 V / 22 AR-134ayes2026-08-13
HPAX-50-DHPT 2**StateCAHP-50 263 × 15 in240 V / 22 AR-134ayes2025-12-12
CAHP-66 2**A. O. SmithCAHP-66 261 × 23 in240 V / 22 AR-134ayes2026-08-13
HPA10-66H45DV 2**A. O. SmithCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
HPTA-66 2**A. O. SmithCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
HPA10266H045DV 2**AmericanCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
CHPA-66 2**LochinvarCAHP-66 261 × 23 in240 V / 22 AR-134ayes2026-08-13
HPPA065KD 2**LochinvarCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
10-66-DHPTA 2**RelianceCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
CSHP-66 2**StateCAHP-66 261 × 23 in240 V / 22 AR-134ayes2026-08-13
HPAX-66-DHPT 2**StateCAHP-66 261 × 23 in240 V / 22 AR-134ayes2025-12-12
CAHP-80 2**A. O. SmithCAHP-80 269 × 27 in240 V / 22 AR-134ayes2026-08-13
HPA10-80H45DV 2**A. O. SmithCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12
HPTA-80 2**A. O. SmithCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12
HPA10280H045DV 2**AmericanCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12
CHPA-80 2**LochinvarCAHP-80 269 × 27 in240 V / 22 AR-134ayes2026-08-13
HPPA080KD 2**LochinvarCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12
10-80-DHPTA 2**RelianceCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12
CSHP-80 2**StateCAHP-80 269 × 27 in240 V / 22 AR-134ayes2026-08-13
HPAX-80-DHPT 2**StateCAHP-80 269 × 27 in240 V / 22 AR-134ayes2025-12-12

Nearest certified alternatives

Rating setFirst hourUEFRated volume
Rheem PROPH65 T2 RH375-15compared with A. O. Smith CAHP-40 2−1 gal−0.05+23 gal
Friedrich PROH40 T2 FD310BMcompared with A. O. Smith CAHP-40 2+5 gal−0.10same gal
Vaughn Thermal ME50HPTcompared with A. O. Smith CAHP-40 2+3 gal−0.14+11 gal
Rheem PROPH50 T2 RH375-15compared with A. O. Smith CAHP-40 2−3 gal+0.15+9 gal
Rheem PROPH80 T2 RH375-15compared with A. O. Smith CAHP-50 2+2 gal+0.02+26 gal

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