40-Gallon Water Heaters

ENERGY STAR certified tank water heaters in the nominal 40-gallon class. Tank size alone doesn't determine capacity — the first-hour rating (how much hot water the unit delivers in its first hour from full) is the number to size by.

34 certified models in this category.

Model Uniform Energy Factor (UEF)FuelFirst-hour ratingMax flow rateRated storage volumeSmart / connected capable
A. O. Smith GC6-PS4050-V 1 40-Gallon 0.9Natural Gas86 gal—38 galNo
A. O. Smith GPCC-40L 1 40-Gallon 0.9Natural Gas, Propane86 gal—38 galNo
A. O. Smith Heat Pump 40-Gallon (CAHP-40 2) 3.6Electric55 gal—36 galYes
A. O. Smith Split System Heat Pump 40-Gallon (HPACO-45 1-+AXST-50T 1) 3.52Electric67 gal—45 galYes
AMERICAN STANDARD WATER HEATERS Heat Pump Water Heater 40-Gallon (ASHPWH-40) 3.58Electric66 gal—37 galYes
AMERICAN STANDARD WATER HEATERS Heat Pump Water Heater 40-Gallon (ASHPWH-50) 3.75Electric68 gal—45 galYes
Arctic-HP-Hot Water-KA06-50 40-Gallon 3.88Electric65 gal—44.5 galNo
Ariston Heat Pump Water Heater 40-Gallon (ARIHPWH-40-T) 3.55Electric65 gal—37 galYes
Ariston Heat Pump Water Heater 40-Gallon (ARIHPWH-50-T) 3.83Electric69 gal—45 galYes
Bradford White RE2H50S 40-Gallon 3.44Electric65 gal—45 galNo
Bradford White RE2HP50-1NCTT 40-Gallon 3.89Electric65 gal—45 galNo
Envirosense ENV-40P 1 40-Gallon 0.9Propane86 gal—38 galNo
Friedrich 12PROG 40-50P FD HE EC3 40-Gallon 0.9Propane88 gal—40 galNo
Friedrich 12PROG 40-50U FD HE EC3 40-Gallon 0.9Natural Gas88 gal—40 galNo
Friedrich Heat Pump 40-Gallon (PROH40 T0 FD120-M) 2.8Electric45 gal—36 galNo
Friedrich Heat Pump 40-Gallon (PROH40 T2 FD310BM) 3.5Electric60 gal—36 galNo
Friedrich Heat Pump 40-Gallon (PROH40 T2 FD350BM) 3.5Electric60 gal—36 galNo
Friedrich Heat Pump 40-Gallon (PROH40 T2 FD400-30) 3.83Electric60 gal—36 galNo
Friedrich Heat Pump 40-Gallon (PROH50 T2 FD310BM) 3.5Electric67 gal—45 galNo
Friedrich Heat Pump 40-Gallon (PROH50 T2 FD350BM) 3.5Electric67 gal—45 galNo
Friedrich Heat Pump 40-Gallon (PROH50 T2 FD400-15) 3.75Electric52 gal—45 galNo
Friedrich Heat Pump 40-Gallon (PROH50 T2 FD400-30) 3.88Electric67 gal—45 galNo
GE Profile Heat Pump 40-Gallon (PF40S10FPY01) 3.1Electric46 gal—40 galYes
GE Profile Heat Pump 40-Gallon (PH40S10BPY01) 4.2Electric64 gal—40 galYes
Navien NWP500 40-Gallon 3.85Electric65 gal—44 galNo
Rheem Heat Pump 40-Gallon (PRO H40 T2 RH310BM) 3.5Electric60 gal—36 galNo
Rheem Heat Pump 40-Gallon (PROPH40 T0 RH120-M) 2.8Electric45 gal—36 galNo
Rheem Heat Pump 40-Gallon (PROPH40 T2 RH375-30) 3.83Electric60 gal—36 galNo
Rheem Heat Pump 40-Gallon (PROPH50 T2 RH375-15) 3.75Electric52 gal—45 galNo
Rheem Heat Pump 40-Gallon (PROPH50 T2 RH375-30) 3.88Electric67 gal—45 galNo
Rheem PROP G40-50-CN HE 40-Gallon 0.9Natural Gas, Propane88 gal—40 galNo
Richmond Heat Pump 40-Gallon (10E40-HP530) 3.83Electric60 gal—36 galNo
Richmond Heat Pump 40-Gallon (10E40-HP5S30) 3.83Electric60 gal—36 galNo
SANCO2 40-Gallon (GS5-45HPC-D HP + ECO-43SSAQB) 3.7Electric73 gal—43 galNo