Five heat-pump water heaters, scored out of 100 — 240V hybrids and the 120V plug-in
A heat-pump water heater is a tank with a small air conditioner running backwards on top of it: instead of making heat with a resistance wire, it moves heat out of the room air and into the water. That is how a water heater posts a UEF above 3.0 — three-plus units of hot water for every unit of electricity — in a category where a good standard electric tank manages 0.93. The trade is written into the physics: it needs air to steal heat from (about 700 cubic feet of it, or ducting), it cools and dries the room it sits in, and its recovery is slower than a big resistance element, so the first-hour rating matters more here than the gallon count. We score these from manufacturer spec sheets and the DOE database only. We do not bench-test, and we will not pretend otherwise.
The rubric is the house rubric from How We Rate, adapted to the category: heating performance 30, efficiency 25, running cost 25, warranty and parts 20. One structural fact before the scores: the federal 25C credit that used to pay 30% of a heat-pump install expired on December 31, 2025 — so the math below closes on efficiency and state or utility rebates, not on a credit that no longer exists. Any quote you get in 2026 that still leans on 25C is using last year’s numbers.
The shortlist
| Model | Size | UEF | Score |
|---|---|---|---|
| Rheem ProTerra 50 (XE50T10HS45U1) | 50 gal · 240V | 3.88 | 88 |
| Bradford White AeroTherm G2 65 (RE2HP6510) | 65 gal · 240V | 4.20 | 85 |
| A. O. Smith Voltex 50 (HPTU-50N) | 50 gal · 240V | 3.45 | 82 |
| Rheem ProTerra 80 (XE80T10HS45U1) | 80 gal · 240V | 4.07 | 81 |
| Rheem ProTerra Plug-In 50 (PROPH50 T0 RH120) | 50 gal · 120V | 3.00 | 78 |
UEF and first-hour ratings from each maker’s published spec sheet; the AeroTherm figures are Bradford White’s G2 specification sheet values. Specs checked 2026-11-09.
The picks, scored
Rheem ProTerra 50-Gallon Hybrid
88/100
The default answer for an all-electric house, and the hybrid our tank flagship already scores at 86 against gas and electric tanks — on a heat-pump-only field, with efficiency weighted the way this category lives or dies, it takes the top spot. The 3.88 UEF is near the top of the 50-gallon class, LeakGuard leak detection with automatic shutoff is the feature owners actually write home about, and EcoNet scheduling lets the tank heat when your power is cheapest. The honest trade-offs are the category’s, not this model’s: it wants roughly 700 cubic feet of air or a duct kit, it will cool and dehumidify the room it sits in, and its 67-gallon first hour trails the big gas burners. Sold through Home Depot and plumbing channels.
- ModelXE50T10HS45U1
- First-hour rating67 gal
- Recovery (90°F rise)27 gal/hr
- UEF3.88
- Warranty10 yr tank & parts
Bradford White AeroTherm G2 65-Gallon
85/100
The highest efficiency number on this page: 4.20 UEF on Bradford White’s G2 specification sheet, with an 82-gallon first hour that embarrasses most 50-gallon tanks and an operating range down to 37°F before the elements take over. The G2 also carries a CTA-2045 demand-response port, so a utility can pay you for letting it shift heating off peak hours where programs exist. Why is the efficiency leader second? Channel. Bradford White sells only through licensed plumbers — there is no shelf to buy it from and no Amazon listing we would send you to — so the value of that 4.20 depends entirely on the installed quote you can negotiate, and the parts warranty is the field’s shorter 6-year term on the G2 spec sheet’s warranty columns. If your plumber is a Bradford White house, this is the hybrid to ask for by model number.
- ModelRE2HP6510
- First-hour rating82 gal
- UEF4.20
- Air range37–120°F
- Warranty10 yr tank · 6 yr parts
A. O. Smith Voltex 50-Gallon Hybrid
82/100
The Voltex trails the ProTerra on the two numbers that lead this category — 3.45 UEF against 3.88, 66 gallons first hour against 67 — and matches it where it counts in year nine: the same 10-year tank and parts warranty. That gap in efficiency is worth real money over a decade, which is why it sits third; it is also small enough that channel should break the tie. The Voltex is A. O. Smith’s ProLine XE line, sold through plumbing wholesalers rather than the Lowe’s Signature shelf, so if your installer is an A. O. Smith house or the Rheem is out of stock, this is the pick — the two are close enough that the quote, not the badge, should decide. Our flagship scores it 80 on the mixed-fuel field; here it is scored against hybrids only.
- ModelHPTU-50N
- First-hour rating66 gal
- Recovery (90°F rise)≈25 gal/hr
- UEF3.45
- Warranty10 yr tank & parts
Rheem ProTerra 80-Gallon Hybrid
81/100
The answer when the 50-gallon first-hour math fails a five-person house: an 80-gallon tank whose 87-gallon first hour is the biggest number on this page, at a 4.07 UEF that is somehow better than its smaller sibling’s. Same LeakGuard, same EcoNet, same 10-year warranty. What holds it to fourth is fit, not performance: at 75 inches tall before the fittings, it does not go everywhere a 50-gallon tank came out of, and a household that does not need the volume is paying to heat water it never draws. Size it first — if your peak hour genuinely runs past 70 gallons, this is the hybrid that ends the argument; if it does not, the 50 above is the smarter buy.
- ModelXE80T10HS45U1
- First-hour rating87 gal
- UEF4.07
- Height75 in
- Warranty10 yr tank & parts
Rheem ProTerra Plug-In 50-Gallon (120V)
78/100
The most interesting heater on this page, aimed at one specific house: the one replacing a gas tank whose panel cannot take a new 240V circuit without real money. The Plug-In runs on a 120V, 15-amp circuit — Rheem sells a dedicated-circuit version and a shared-circuit version with HydroBoost, a mixing valve that stores water hotter and delivers more of it at usable temperature. What you give up is written in its own spec table: no resistance backup elements, so recovery is compressor-only at about 29 gallons an hour at a 60°F rise, the first hour is 55 gallons, and the UEF is 3.00 rather than 3.88. For a small household leaving gas, that trade can be worth thousands in avoided electrical work. For a four-bathroom house, it is the wrong tool, and no rebate changes that.
- ModelPROPH50 T0 RH120
- First-hour rating55 gal
- UEF3.00
- Circuit120V · 15A
- Warranty10 yr tank & parts
The deciding numbers, charted
One chart, one question: how efficient is each unit on the DOE’s own scale? A standard electric tank sits at 0.93 UEF — every bar here is three to four times that.
UEF from manufacturer spec sheets (Bradford White: G2 specification sheet), checked 2026-11-09. UEF compares efficiency only — the first-hour ratings in the shortlist are the other half of the decision.
How the scoring works
Heating performance (30) is first-hour rating against the size class — a hybrid that cannot cover the morning peak fails at its only job. Efficiency (25) is UEF, the DOE number, with no credit for marketing multipliers. Running cost (25) works the UEF against typical electric rates and counts what ownership actually involves: a condensate drain that must exist, an air filter that needs rinsing, and the room air the unit borrows. Warranty and parts (20) weighs the 10-year standard this category has settled on, the parts term where it differs, and — decisively for the AeroTherm — whether the brand’s channel will sell you the heater at all. The ProTerra 50 wins because it gives up nothing important: top-tier efficiency, leak protection, a retail channel, and the warranty, in one box.
Why there are no prices on this page
Heat-pump pricing moves with rebates, and rebates move with your ZIP code — the same ProTerra is a different proposition under a $750 utility rebate than without one. Rather than print a number that is wrong by Friday, we print the numbers that do not move: UEF, first-hour rating, warranty terms. What the full job should cost installed — and the expired-credit trap to check in every 2026 quote — lives on Water Heater Replacement Cost.
Keep reading
From the desk
- 1Best Tank Water Heaters — the flagship comparison, where two of these hybrids compete against gas and electric tanks
- 2Tankless vs tank — the decision page, if on-demand is still in your mix
- 3What the install really costs — unit, labor, permit, and the expired 25C credit, itemized
- 4Tank hub — every tank class, graded before you need one