AO Smith Voltex Hybrid Heat Pump 50-Gallon Water Heater

The AO Smith Voltex Hybrid Heat Pump 50-Gallon Water Heater (HPTU-50N) is AO Smith's flagship in the heat-pump-water-heater category — the model that competes directly with the Rheem ProTerra for the premium electric heat-pump dollar. 3.42 UEF. 67 GPH first-hour delivery in hybrid mode. 10-year warranty. Federal IRA tax credit + state/utility rebates eligible. The Voltex's distinguishing characteristics: quieter operation (~48 dBA vs ProTerra's 55 dBA), and AO Smith's plumber-distributor network that some buyers prefer over Rheem's big-box-channel distribution.

Headline specifications

• Capacity: 50 gallons
• Fuel: Electric (heat pump primary + 4,500W resistance backup)
• First Hour Delivery: 67 GPH (hybrid mode)
• Energy Factor (UEF): 3.42
• Sound level: ~48 dBA (quieter than competing Rheem ProTerra at ~55 dBA)
• Warranty: 10-year tank + sealed heat-pump system
• Operating modes: Heat Pump, Hybrid, Electric, Vacation
• Connectivity: iCOMM app via optional WiFi module
• Dimensions: 64" H × 22.25" diameter, ~217 lbs dry
• Ambient air: 700+ cubic feet required; condensate drain required

Where the Voltex beats the ProTerra

Noise. The Voltex runs at about 48 dBA at typical user distance — roughly the noise level of a quiet dishwasher. The ProTerra runs at about 55 dBA — closer to a window AC. The 7 dB difference is significant. For installs adjacent to bedrooms or living spaces (basements with finished areas above), the Voltex is the better neighbor.

Plumber-distributor network. AO Smith has stronger relationships with independent plumbers in many regions; Rheem has stronger consumer-channel availability at Home Depot. If your plumber sources from an AO Smith distributor, the Voltex install pipeline is smoother.

Slightly lower profile. The Voltex is 64" tall vs the ProTerra's 65.5" — a small but sometimes-decisive difference for installs with tight vertical clearance.

Where the ProTerra beats the Voltex

UEF (3.55 vs 3.42). Rheem's slight efficiency edge translates to about 4% lower operating cost over the unit's life. On a $100/year electric bill that's $4/year — not decisive but real.

EcoNet WiFi built-in vs Voltex's optional iCOMM module. The ProTerra ships WiFi-enabled out of the box with leak detection and scheduling. The Voltex requires a separately purchased WiFi module ($80–$120) for app connectivity, and the iCOMM ecosystem is less mature than EcoNet.

Consumer-channel availability. The ProTerra is widely stocked at Home Depot. The Voltex is more plumber-channel oriented.

Who this model is for

Same general buyer profile as the ProTerra:

• 700+ cubic feet ambient air install space (basement, garage, utility room)
• Condensate drain available or installable
• Existing 30-amp 240V electric water heater circuit
• Willing to absorb $1,500–$1,800 upfront for the rebate-eligible efficiency upgrade
• Long ownership horizon (8+ years) where the operating-cost savings compound

Choose the Voltex over the ProTerra if: (a) install is acoustically sensitive (basement with finished space above, near bedrooms), (b) your plumber recommends AO Smith specifically based on their distributor relationships, or (c) you're indifferent on WiFi integration and care about the noise differential.

Where it falls short

UEF 3.42 vs ProTerra 3.55. A few percent slower at the same task. Negligible to most buyers.

iCOMM WiFi module sold separately. If smart-home integration matters, expect an additional $80–$120 and a separate setup procedure.

Same install constraints as all heat pump water heaters. 700 cu ft ambient air, condensate drain required, cool air output, slower recovery in pure heat pump mode, taller and heavier than standard tanks. None of these are Voltex-specific — they're inherent to the heat-pump architecture.

Plumber-channel orientation can be a downside for DIY-leaning buyers who want to source the unit themselves. The Voltex is at Lowe's and via online plumbing distributors, but not as broadly available as the ProTerra.

Install considerations

Same as ProTerra: 700+ cu ft ambient air, condensate drain, dedicated 30-amp 240V circuit, clearance for 64" height and 22.25" diameter, and permits in most jurisdictions.

The lower noise level of the Voltex makes it more forgiving of installs in semi-finished spaces — but install in finished living areas is still not recommended.

Install cost: $1,800–$3,000 typical. Net cost after IRA tax credit + state/utility rebates often $500–$1,200.

Rebates and tax credits

Same eligibility as the ProTerra and other ENERGY STAR-rated heat pump water heaters:

• Federal IRA Tax Credit: 30% of installed cost, up to $2,000, through 2032
• State rebates: CA, MA, NY, ME, MD, OR, WA programs apply
• Utility rebates: $200–$500 from most major US utilities

The Voltex's UEF 3.42 clears every major rebate threshold. Confirm rebate stacking eligibility on DSIREUSA.org for your specific state.

Maintenance

• Annual flush — standard tank flushing procedure
• Annual air filter clean — washable filter, 5-minute task
• Anode rod check at year 3–4, replace at year 6
• Condensate drain inspection
• Optional iCOMM module firmware updates if installed

Bottom line

The AO Smith Voltex Hybrid Heat Pump 50-Gallon is the equivalent-tier alternative to the Rheem ProTerra in the heat-pump-water-heater category. The Voltex wins on noise level and AO Smith distributor relationships; the ProTerra wins on UEF, WiFi-out-of-the-box, and Home Depot availability. For most buyers either unit is an excellent choice — the deciding factor is usually local distributor pricing and acoustic sensitivity of the install location. Both qualify for the same federal and state rebates. Click through to Amazon for live pricing; for plumber-channel pricing, contact an AO Smith distributor in your area.