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Ariston ARIHPWH-40-T

Ariston ARIHPWH-40-T 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 37 gallons, a certified UEF of 3.55, and a certified first-hour rating of 65 gallons of hot water.

Its advertised UEF of 3.55 from Ariston matches the certified 3.55 (Read Oct 5, 2026).

  • Heat pump water heater
  • 2 listed models
Storage volume
37gallons
UEF
3.55Uniform energy factor
First-hour rating
65gallonsHot water in the first hour
See it among every heat pump model

Product history

Ariston ARIHPWH-40-T was in the DOE listing by Oct 1, 2026.

Ariston ARIHPWH-40-T has a recorded ENERGY STAR market-availability date of Sep 1, 2025. It first appeared in the ENERGY STAR list between October 2025 and February 2026.

Advertised and certified figures

Ariston ARIHPWH-40-T: advertised and certified
Ariston ARIHPWH-40-T: advertised and certified Size: advertised 40 gal, certified 37 gal (advertised nominal size, certified storage volume). Size: advertised 37 gal, certified 37 gal (certified storage volume). UEF: advertised 3.55, certified 3.55. First-hour rating: advertised 65 gal, certified 65 gal. Size · advertised nominal size, certified storage volume Advertised 40 gal Certified 37 gal Size · certified storage volume Advertised 37 gal Certified 37 gal UEF Advertised 3.55 Certified 3.55 First-hour rating Advertised 65 gal Certified 65 gal
FigureAdvertisedCertifiedAdvertiserRead
Size 40 gal, nominal size 37 gal storage volume Ariston Read Oct 5, 2026
Size 37 gal 37 gal storage volume Ariston Read Oct 5, 2026
UEF 3.55 3.55 Ariston Read Oct 5, 2026
First-hour rating 65 gal 65 gal Ariston Read Oct 5, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
ARIHPWH-40 MAX373.5565407%Medium
ARIHPWH-40-T373.5565407%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
ARIHPWH-40-T373.5565407%

It holds 37 gallons in the test, 3 gallons less than its 40-gallon sold size. Over one hour from a full tank, it gave 65 gallons in the test (its first-hour rating). Its tank holds 37 gallons, so reheating adds 28 gallons during the first hour. Of 481 heat pump models, 346 give more hot water in the first hour. Among heat pump models, the median first-hour rating is 72 gallons.

Of its 2 model numbers, one is ENERGY STAR certified. For each unit of energy it uses, 3.55 units end up in the hot water (its UEF). It moves heat from the air rather than making it, so its UEF passes 1. Its test ran at the medium level of daily hot water use. Its UEF is lower than that of 122 of the 226 heat pump models with its draw pattern. On its draw pattern, the median heat pump UEF is 3.68. While it reheats, the water gains 407% of the energy it uses (its recovery efficiency).

It is the basic model for ARIHPWH-40 MAX and ARIHPWH-40-T. All of its test figures are shared by one other basic model. The brand name on that one is Lennox.

In 20 states, 21 rebate programs may accept it. Another 7 programs may accept it if it meets their other terms.

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.