A.O. Smith Voltex MAX 80 Gal vs Rinnai REHP80

Last updated: October 21, 2026

The A.O. Smith Voltex MAX 80 Gal is the better heat pump water heater overall, rated 3.8 to 3.7. The A.O. Smith Voltex MAX 80 Gal leads on hot water and noise. The Rinnai REHP80 wins on efficiency. The Rinnai REHP80 costs $300 less ($2,699 vs $2,999).

A.O. Smith Voltex MAX 80 Gal vs Rinnai REHP80

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?

Scores side by side

Each factor is scored 0-100 against the same fixed reference points for every 80 gallon heat pump water heater; a clear win is highlighted. How we rank explains each one.

Factor weightA.O. Smith Voltex MAX 80 GalRinnai REHP80
Overall rating3.8/53.7/5
Efficiency 35%63 3.88 UEF71 4.00 UEF
Hot water 20%80 95 gallons in the first hour64 91 gallons in the first hour
Warranty 20%75 10-year tank, 10-year parts, 1-year labor75 10-year tank, 10-year parts, 1-year labor
Cold rooms 15%32 heat pump runs down to 37 °F room air30 heat pump runs down to 37.4 °F room air
Noise 10%69 45 dB(A)44 49 dB(A)

Specifications

A.O. Smith Voltex MAX 80 GalRinnai REHP80
Ratings (ENERGY STAR)
Size (nominal)80 gal80 gal
Tank volume (measured)81 gal75 gal
Uniform Energy Factor3.884.00
First-hour rating95 gal91 gal
Draw patternHighHigh
Yearly energy use1,279 kWh1,225 kWh
Heat pump cut-off (low)37 °F37.4 °F
Sound level45 dB(A)49 dB(A)
ENERGY STAR ID34175623531242
Installation
Power240 V240 V
Circuit30 A, 208/240 V30 A, 208/240 V
Backup element4,500 W4,500 W
Operating air range37 to 120 °F37 to 107 °F
Minimum room size450 cu ft700 cu ft
Size69 in tall, 27 in across74.2 in tall, 25.7 in across
Weight302 lb290 lb
RefrigerantR-134aR-134a
Features
Wi-FiBuilt inNo
AppA. O. Smith (iCOMM)-
Demand response port (CTA-2045)Yes-
Leak detectionYesNo
ModesHybrid, Heat Pump, Hot Water+ (3 levels), Guest, Electric, VacationEconomy, Heat Pump, Hybrid, E-Heater, Vacation
Warranty and models
Warranty10 yr tank, 10 yr parts, 1 yr labor10 yr tank, 10 yr parts, 1 yr labor
Also sold asAmerican HPA10280H045DV, Lochinvar HPPA080KD, Reliance 10-80-DHPTA, State HPAX-80-DHPT-
Released2024-032024-08