Rheem vs AO Smith Head-to-Head Comparison for Homeowners
Quick Answer: Rheem leads in energy efficiency (UEF 3.45–4.07) and innovation (EverKleen sediment reduction, smart features). AO Smith wins on warranty (12-year parts on premium models) and product breadth. For Utah’s hard water, Rheem’s EverKleen self-cleaning system justifies the $300–$500 premium. For soft-water regions or budget-conscious buyers, AO Smith offers excellent value. Both are industry-leading; your choice depends on priorities.
Head-to-Head Specs
FeatureRheemAO SmithWinnerEnergy Efficiency (UEF)3.45–4.07 (heat pump)3.5–3.88 (heat pump)RheemAverage Lifespan12–15 years10–12 yearsRheemWarranty (tank)6–10 years6–12 yearsAO Smith (longer on premium)Warranty (parts)6–10 years6–12 yearsAO SmithLabor warranty1–5 years1–5 yearsTiePrice (electric 50 gal)$1,200–$1,500$1,000–$1,300AO Smith (cheaper)Smart featuresEcoNet (WiFi) standardLimited on entry modelsRheemSediment handlingEverKleen self-cleaningStandard filterRheemTankless optionsFewer modelsMore varietyAO SmithUtah hard-water ratingExcellent (EverKleen)Good (standard)Rheem
Round 1: Efficiency & Operating Costs
Rheem’s advantage:
Rheem’s heat pump models achieve UEF 3.45–4.07, meaning they generate 3.45–4.07 units of heat for every unit of electricity consumed. AO Smith’s comparable models (Vertex series) reach 3.5–3.88 UEF.
Real-world impact: A Rheem 80-gallon heat pump costs approximately $400–$500/year in energy. Same capacity AO Smith costs $450–$550/year. Over 15 years, Rheem saves $750–$1,500 in energy costs.
AO Smith’s response: Condensing gas models (Vertex series) are highly efficient. For gas heaters specifically, the brands are nearly tied.
Winner: Rheem for heat pump (electric) and overall efficiency. AO Smith competitive for gas.
Utah impact: Lower energy costs matter less than sediment problems. Hard water reduces efficiency on all brands. See Round 5 below.
Round 2: Warranty Coverage
AO Smith’s advantage:
AO Smith offers 12-year tank warranty on premium models (vs. Rheem’s 6–10). If your tank rusts through in year 8, Rheem won’t cover replacement cost; AO Smith will.
Rheem’s response: 10-year warranty on heat pump models is competitive. Six-year warranty on entry models is industry-standard.
Real-world: Tank rust-through occurs in 2–5% of heaters, usually due to improper installation or neglect. For well-maintained heaters, warranty length matters less. But if you want peace of mind, AO Smith’s 12-year coverage is superior.
AO Smith catches: Parts warranty also extends to 12 years on premium, meaning if a thermostat fails in year 9, AO Smith covers parts. Rheem’s parts warranty typically ends at year 6–8.
Winner: AO Smith for warranty length. However, Rheem’s reputation for longevity means claims are rarer.
Round 3: Features & Innovation
Rheem’s advantage:
EcoNet WiFi integration: Monitor tank temperature, adjust schedules, set vacation mode, receive leak alerts. Critical for freeze prevention in Utah winter.
EverKleen self-cleaning: This is Rheem’s biggest differentiator for Utah. A self-cleaning system continuously flushes sediment away from the heating element. Over 15 years, this prevents sediment buildup that would reduce efficiency by 20–30% on untreated tanks.
AO Smith’s response:
Vertex technology: Advanced condensing on gas models. Captures heat from exhaust gases, increasing efficiency. Standard filtration but no “self-cleaning” automation.
Smart features: Lower-tier AO Smith models lack WiFi. You need to buy premium to get smart connectivity. Rheem bundles it across more models.
Winner: Rheem for innovation and standard-across-lineup smart features. AO Smith requires premium models for WiFi.
Utah impact: EverKleen justifies Rheem’s premium for hard-water homeowners. If water is soft (mountain areas), EverKleen’s value decreases.
Round 4: Product Range
AO Smith’s advantage:
AO Smith offers 15+ distinct product lines:
Electric tank (entry to premium)
Gas tank (traditional to condensing Vertex)
Heat pump
Hybrid (electric + heat pump)
Tankless (multiple flow rates)
Commercial/industrial
Indirect heating (for boiler systems)
Rheem’s range is narrower (6–8 lines). If you need a specific size or fuel type, AO Smith likely has more options.
Winner: AO Smith for variety.
Practical impact: For most Utah homeowners, this doesn’t matter. Both brands have your size/fuel type. But contractors appreciate AO Smith’s breadth for complex jobs (boilers, multi-unit buildings).
Round 5: Utah Hard Water Performance
This is the deciding factor for Utah buyers.
Utah’s Wasatch Front has 14–22 GPG hardness. Spanish Fork, Payson, and Uinta Basin reach 22+ GPG. Hard water mineral (calcium and magnesium) accumulates on heating elements and inside tankless heat exchangers.
Rheem’s EverKleen:
A self-cleaning dip tube inside the tank slowly drains sediment toward the drain valve. Over years, this prevents massive accumulation. Result:
Year 1–5: Element efficiency maintained at 95%+
Year 10: Element efficiency still 85–90%
Sediment drains naturally with annual flushes
AO Smith standard approach:
Normal dip tube (no self-cleaning feature). Sediment settles at the bottom. Requires annual flushing to remove.
Year 1–5: Element efficiency maintained at 95%+
Year 10: Element efficiency 70–80% (unless flushed every 6 months in hard water)
Sediment can clog inlet or outlet connections without discipline
Real-world Utah performance:
Rheem heat pump: Annual maintenance, steady efficiency, 15-year lifespan common.
AO Smith standard: Requires 6-month flushing in hard water to avoid 20%+ efficiency loss. Same lifespan but requires more discipline.
Cost comparison over 15 years in hard water:
Rheem EverKleen: $1,400 purchase, $100/year × 15 = $1,500 maintenance, $7,200 energy = $10,100 total
AO Smith standard: $1,100 purchase, $200/year × 15 = $3,000 maintenance (more frequent flushing + higher energy due to sediment), $8,100 energy = $12,200 total
Rheem saves $2,100 over 15 years in hard-water environments.
Winner: Rheem for Utah. EverKleen’s value is immense in hard water.
Round 6: Price & Value
AO Smith’s advantage for budget buyers:
Entry-level AO Smith electric tank: $1,000–$1,100
Entry-level Rheem electric tank: $1,200–$1,300
AO Smith is $200–$300 cheaper upfront. If you’re replacing and keeping costs minimal, AO Smith is appealing.
Rheem’s advantage for long-term value:
Higher purchase price offset by:
Better efficiency (lower energy bills)
Longer lifespan (less frequent replacement)
EverKleen (less maintenance in hard water)
Over 15 years, Rheem is cheaper despite higher initial cost.
Winner: AO Smith for upfront cost. Rheem for total cost of ownership in hard water.
Which Should You Choose?
Choose Rheem if:
You live in Utah’s hard-water areas (Wasatch Front, Spanish Fork, Provo)
You want WiFi/smart features
You prioritize energy efficiency
You plan to stay 10+ years (long-term value)
You want minimal maintenance hassles
Choose AO Smith if:
You’re budget-conscious and want lower upfront cost
You live in soft-water areas (mountains, northern Utah)
You need a specific product type (they have more variety)
You prioritize longest warranty coverage
You’re comfortable flushing every 6 months in hard water
Tie-breaker for Utah: Ask your local plumber which they standardize on. If they service Rheem regularly, that relationship matters. If they push AO Smith strongly, there’s likely a service reason (parts availability, reliable performance in your area). Contractor expertise > brand loyalty.
Real-World Installation Costs
TypeRheemAO SmithLabor (Both)Electric 50 gal$1,200–$1,500$1,000–$1,300$600–$900Gas 40 gal$1,100–$1,400$1,000–$1,300$600–$900Heat pump 80 gal$2,000–$2,400$1,800–$2,200$800–$1,200Tankless (gas)$2,200–$2,800$2,000–$2,700$1,000–$1,500
Note: Installation costs vary by location and complexity. Mountain areas cost 20–30% more. New construction costs less than replacement (existing plumbing).
Warranty: What Actually Matters
Rheem: Covers parts/labor for 6–10 years. Requires proof of annual maintenance. Smart features (EcoNet) have 5-year coverage.
AO Smith: Covers parts/labor for 6–12 years depending on model. Warranty is transferable to new owner if selling home (good for resale).
Reality: 70% of water heaters are replaced due to age/efficiency, not warranty claims. The “longer warranty” argument matters less than you think if the unit lasts 12+ years anyway.
Find Local Help
Deciding between Rheem and AO Smith is easier with contractor input. Ask your plumber which they recommend specifically for your water hardness and usage.
Find a local installer: Browse by city
Request quotes from both: Get Rheem and AO Smith options side-by-side
Ask the deciding question: “Which do you see last longer in our area’s water?
Frequently Asked Questions
Q: Can I go wrong with either choice?
A: No. Both are excellent brands. The $300 premium for Rheem is justified in Utah hard water but not everywhere.
Q: Is Rheem’s EverKleen worth the premium?
A: In Utah hard water (14+ GPG), absolutely. Over 15 years, it saves $2,000+ in maintenance and energy. In soft water, it’s a nice-to-have but not essential.
Q: Which has better customer service?
A: Both are excellent. Rheem has more WiFi integration (better app support). AO Smith has more local service centers in some areas. Call both 1-800 numbers and judge responsiveness yourself.
Q: Can I mix and match parts?
A: No. Parts are brand-specific. You can’t use a Rheem element in an AO Smith tank. Buy from contractors who stock your brand.
Q: What if my plumber only sells one brand?
A: That’s normal. Plumbers specialize for warranty/parts/training efficiency. If they only sell Rheem or AO Smith, ask why. If their answer is credible (hard water experience, reliable supply chain), trust their judgment.
Q: Can I save money by buying online and hiring a plumber to install?
A: Possible but risky. Online purchases may lack warranty support from retailers. Plumbers prefer you buy from them (guarantees correct parts, warranty support). Buying retail then hiring installation is a gray area—verify warranty before proceeding.
Sources and Update Policy
This article compares Rheem and AO Smith specifications, efficiency ratings, warranty terms, and Utah hard-water performance as of March 2026. Information sourced from Rheem product specs, AO Smith product specs, efficiency comparisons, and Utah contractor feedback. We update this comparison semi-annually as new models launch and efficiency ratings change.