A.O. Smith Voltex MAX 66 Gal
#3 in 65 GallonFull review
A solid 240 V heater with leak protection included, sold at Lowe’s as the Signature 900 line.
Lowe's $2,579$2,579
The A.O. Smith Voltex MAX 66 Gal and the Rheem ProTerra 65 Gal are evenly matched, rated 3.8 and 3.8. The A.O. Smith Voltex MAX 66 Gal leads on hot water. The Rheem ProTerra 65 Gal wins on efficiency. The Rheem ProTerra 65 Gal costs $290 less ($2,289 vs $2,579).
Rheem ProTerra 65 Gal
#4 in 65 GallonFull review
A strong 240 V choice with Wi-Fi, widely stocked at Home Depot. GE Profile beats it on efficiency and noise.
Home Depot $2,289$2,289
Prices were last checked October 21, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the A.O. Smith Voltex MAX 66 Gal for hot water (83 gallons in the first hour vs 75 gallons in the first hour).
- Choose the Rheem ProTerra 65 Gal for efficiency (4.05 UEF vs 3.84 UEF).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 65 gallon heat pump water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | A.O. Smith Voltex MAX 66 Gal | Rheem ProTerra 65 Gal |
|---|---|---|
| Overall rating | 3.8/5 | 3.8/5 |
| Efficiency 35% | 60 3.84 UEF | 75 4.05 UEF |
| Hot water 20% | 92 83 gallons in the first hour | 60 75 gallons in the first hour |
| Warranty 20% | 75 10-year tank, 10-year parts, 1-year labor | 75 10-year tank, 10-year parts, 1-year labor |
| Cold rooms 15% | 32 heat pump runs down to 37 °F room air | 32 heat pump runs down to 37 °F room air |
| Noise 10% | 69 45 dB(A) | 69 45 dB(A) |
Specifications
| A.O. Smith Voltex MAX 66 Gal | Rheem ProTerra 65 Gal | |
|---|---|---|
| Ratings (ENERGY STAR) | ||
| Size (nominal) | 66 gal | 65 gal |
| Tank volume (measured) | 68 gal | 59 gal |
| Uniform Energy Factor | 3.84 | 4.05 |
| First-hour rating | 83 gal | 75 gal |
| Draw pattern | High | High |
| Yearly energy use | 1,292 kWh | 1,184 kWh |
| Heat pump cut-off (low) | 37 °F | 37 °F |
| Sound level | 45 dB(A) | 45 dB(A) |
| ENERGY STAR ID | 3417561 | 3554223 |
| Installation | ||
| Power | 240 V | 240 V |
| Circuit | 30 A, 208/240 V | 30 A, 208/240 V |
| Backup element | 4,500 W | 4,500 W |
| Operating air range | 37 to 120 °F | 37 to 145 °F |
| Minimum room size | 450 cu ft | 700 cu ft |
| Size | 61 in tall, 23 in across | 64.2 in tall, 24.3 in across |
| Weight | 284 lb | 245 lb |
| Refrigerant | R-134a | R-134a |
| Features | ||
| Wi-Fi | Built in | Built in |
| App | A. O. Smith (iCOMM) | EcoNet |
| Demand response port (CTA-2045) | Yes | Yes |
| Leak detection | Yes | No |
| Modes | Hybrid, Heat Pump, Hot Water+ (3 levels), Guest, Electric, Vacation | Energy Saver, Heat Pump, High Demand, Electric, Vacation |
| Warranty and models | ||
| Warranty | 10 yr tank, 10 yr parts, 1 yr labor | 10 yr tank, 10 yr parts, 1 yr labor |
| Also sold as | American HPA10266H045DV, Lochinvar HPPA065KD, Reliance 10-66-DHPTA, State HPAX-66-DHPT | Friedrich PROH65 T2 FD400-30, Friedrich PROH65 T2 FD400-SO, Rheem PROPH65 T2 RH375-30, Rheem PROPH65 T2 RH375-SO, Rheem PROPH65 T2 RH400-30, Rheem PROPH65 T2 RH400-SO, Richmond 10E65-HP530, Richmond 10E65-HP5S30, Richmond 10E65-HP5U30, Richmond 10E65-HP5US30, Ruud PROUH65 T2 RU375-30, Ruud PROUH65 T2 RU375-SO, Ruud PROUH65 T2 RU400-30, Ruud PROUH65 T2 RU400-SO |
| Released | 2024-03 | 2024-06 |