AO Smith vs Rheem Water Heater

Your water heater is one of the most important appliances in your home. It provides hot water for showers, dishes, laundry, and more. So when it’s time to buy a new one, you need to get it right—because the wrong choice can cost you in energy bills, repairs, or a frustrating lack of hot water.

Two of the biggest names in the water heater market are AO Smith and Rheem. Both brands have long-standing reputations and offer a wide range of water heaters for various home sizes, fuel types, and budgets. But which one is better?

This comparison dives deep into each brand’s strengths and weaknesses. We’ll look at everything from product offerings and efficiency to durability, pricing, and customer satisfaction. By the end, you’ll know which brand fits your needs best.

AO Smith and Rheem at a Glance

At first glance, AO Smith and Rheem look pretty similar. Both offer:

• Electric, gas, tank, tankless, and hybrid models
  
• ENERGY STAR® certified units
  
• Strong warranties
  
• Residential and commercial options
  

However, there are key differences in build quality, innovation, and long-term reliability. Some models may be better suited for high-demand households, while others shine in energy savings or smart home compatibility.

Let’s explore what each brand brings to the table.

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Brand Overview

AO Smith – History and Reputation

AO Smith has been around since 1874, originally starting in metal products before transitioning into water heater manufacturing. Today, they are one of the leading manufacturers of residential and commercial water heaters in the U.S. and globally.

Key facts about AO Smith:

• Headquartered in Milwaukee, Wisconsin
  
• Manufactures in the U.S., Canada, Mexico, and China
  
• Owns popular sub-brands like State Water Heaters and American Water Heaters
  
• Focuses heavily on innovation and high-efficiency systems
  

AO Smith is particularly well-known for its long-lasting tank models and cutting-edge hybrid heat pump water heaters. Their models are frequently used in commercial applications, lending extra credibility to their durability claims.

Customers praise AO Smith for:

• Reliable performance
  
• Long lifespan (especially with proper maintenance)
  
• Competitive energy efficiency
  

They’ve built a name as a dependable, mid- to high-tier brand that delivers quality across a wide range of price points.

Rheem – History and Reputation

Founded in 1925, Rheem is one of the largest manufacturers of water heating products in North America. The company is known for both residential and commercial systems and also produces HVAC equipment and pool/spa heaters.

Key facts about Rheem:

• Headquartered in Atlanta, Georgia
  
• Parent company: Paloma Industries (based in Japan)
  
• Offers water heating products under Rheem and Ruud brand names
  
• Focuses on affordability and innovation
  

Rheem is especially popular among homeowners who want affordable yet efficient water heaters. Their Performance Platinum line is a top-seller at Home Depot, thanks to strong features at a competitive price.

Customers like Rheem because:

• Their units are easy to find and install
  
• The brand offers excellent support for DIYers
  
• They offer smart models with Wi-Fi connectivity and energy monitoring
  

While not always considered the most “premium” option, Rheem has earned a reputation for offering value-driven solutions without compromising too much on quality.

Product Range Comparison

1. Tank Water Heaters

Both AO Smith and Rheem offer traditional tank-style water heaters in a wide range of capacities—from compact 20-gallon units to high-demand 80-gallon models.

AO Smith:

• Offers more high-recovery models suited for large households
  
• Available in electric, natural gas, propane
  
• More commonly found in plumbing supply stores and through contractors
  

Rheem:

• Very accessible at big-box retailers like Home Depot
  
• Strong focus on ease of installation
  
• Better for homeowners looking for budget-friendly models
  

Verdict: If you want a basic, reliable tank heater that’s easy to find and install, Rheem may be the way to go. But if you’re looking for commercial-grade quality or higher recovery rates, AO Smith has the edge.

2. Tankless Water Heaters

Tankless models are where these brands start to separate more clearly.

AO Smith:

• Offers both condensing and non-condensing units
  
• Emphasizes commercial-grade heat exchangers
  
• Higher GPM options for large homes
  
• Advanced venting configurations
  

Rheem:

• More consumer-friendly tankless units
  
• Easy digital controls, Wi-Fi available
  
• Widely available and generally more affordable
  
• Includes RTEX electric tankless models for smaller homes or apartments
  

Verdict: For most homes, Rheem’s tankless options are more budget-friendly and easier to find, while AO Smith’s higher-end tankless units deliver better performance for larger households.

3. Hybrid and Heat Pump Models

This category is increasingly popular as energy costs rise.

AO Smith:

• Industry leader in hybrid technology
  
• Offers Voltex Hybrid water heaters with up to 3.45 UEF (Uniform Energy Factor)
  
• Quiet operation, built-in diagnostic tools, ENERGY STAR® certified
  

Rheem:

• Offers the ProTerra Hybrid Electric with similar features
  
• Includes smart home integration (EcoNet app)
  
• Slightly more affordable than AO Smith’s comparable models
  

Verdict: AO Smith is known for heat pump innovation, but Rheem’s models are more accessible and offer nearly identical features for less money.

4. Solar and Eco-Friendly Options

AO Smith:

• Offers complete solar kits with backup tanks
  
• Typically sold through contractors or specialty suppliers
  

Rheem:

• Limited solar options but strong in hybrid electric and gas condensing models
  

Verdict: AO Smith is stronger for solar-specific systems, but Rheem competes well on overall eco-friendliness through hybrid and tankless efficiency.

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Product Line Comparison

Performance and Efficiency

Energy Efficiency Ratings

When it comes to energy efficiency, both AO Smith and Rheem are solid contenders—but their strengths lie in slightly different areas.

AO Smith water heaters tend to offer higher Uniform Energy Factor (UEF) ratings across their hybrid and high-efficiency tank models. For instance, the Voltex Hybrid Electric models boast UEF ratings as high as 3.45, making them one of the most energy-efficient options on the residential market. AO Smith also produces high-recovery gas units that maximize heat transfer and reduce standby losses.

Rheem, on the other hand, focuses more on affordable ENERGY STAR® qualified options, especially in their Performance and Performance Platinum lines. Rheem’s ProTerra Hybrid series still holds its own with UEF ratings up to 3.75, making it a viable competitor to AO Smith’s hybrids.

Both brands also offer condensing tankless units that maximize heat efficiency by recycling exhaust gases, with UEFs above 0.90.

Verdict: It’s nearly a tie, but AO Smith edges out slightly in raw efficiency, particularly in commercial-grade and hybrid models. Rheem leads in user-friendly efficiency—models that offer smart features and ENERGY STAR® ratings at a lower upfront cost.

Recovery Rate and First-Hour Rating

The recovery rate refers to how quickly a water heater can replenish hot water. The first-hour rating (FHR) combines tank size and recovery rate to show how much hot water you can expect in an hour of continuous use.

• AO Smith generally delivers higher first-hour ratings, especially in its Signature Premier and Commercial ProLine series. Their gas heaters are engineered for faster heat-up time, making them ideal for large families or high-demand usage.
  
• Rheem tank heaters have decent recovery rates, but prioritize steady, moderate performance over speed. However, their EcoNet smart models allow users to schedule heating cycles, boosting hot water availability during peak hours.
  

Verdict: AO Smith wins in terms of raw performance and fast recovery—ideal for homes with multiple bathrooms or large water usage needs.

Smart Technology Integration

This is where Rheem takes a clear lead. Their EcoNet platform offers:

• Wi-Fi enabled controls
  
• Leak detection and alerts
  
• Energy usage tracking
  
• Remote temperature adjustment
  

Rheem has been proactive in developing user-friendly apps that integrate seamlessly with smart homes, including Alexa and Google Assistant compatibility.

AO Smith also offers connected water heaters, especially in its Voltex line, but lacks the same app polish and smart ecosystem Rheem provides.

Verdict: If smart tech matters to you, Rheem is the clear winner with its EcoNet suite.

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Durability and Lifespan

Materials and Build Quality

Durability often comes down to materials—and both AO Smith and Rheem use premium-grade steel for their tanks, with glass lining to resist corrosion.

AO Smith:

• Uses Blue Diamond® glass coating for superior corrosion resistance
  
• High-end models feature brass drain valves, which last longer than plastic
  
• More models with commercial-grade heat exchangers
  

Rheem:

• Uses EverKleen™ self-cleaning systems to reduce sediment buildup
  
• Offers resistored heating elements in electric models to combat scale
  
• Slightly more plastic components in budget models
  

AO Smith’s emphasis on heavy-duty materials gives their units a longer reputation for toughness—especially in hard water conditions.

Warranty Length and Coverage

Both brands offer strong warranties, but there are key differences:

AO Smith tends to offer longer warranties on mid-range and commercial models, while Rheem’s warranty is more uniform across all residential lines.

It’s also worth noting that warranty terms may require professional installation or registration—so read the fine print.

Verdict: AO Smith slightly outpaces Rheem in terms of long-term durability and premium material use. For homeowners in hard water areas or seeking long-term value, this could be a deciding factor.

Installation and Maintenance

Installation Ease and Requirements

Both brands are designed with standardized fittings and connections, but Rheem is generally considered easier to install, especially for DIYers.

• Rheem models are widely available at Home Depot and come with user-friendly manuals, plus access to a massive library of online tutorials and tech support.
  
• AO Smith units are more likely to be sold through plumbing supply houses, meaning they’re often installed by licensed professionals. Some models may have more specific space, venting, or clearance requirements.
  

Tankless units from both brands require special venting and gas line upgrades, making professional installation almost mandatory.

Verdict: For DIY installs or simple replacements, Rheem has the edge. For more complex installs or top-tier performance, AO Smith shines with contractor-grade builds.

Maintenance Needs and Serviceability

All water heaters need routine maintenance like:

• Flushing the tank (for sediment removal)
  
• Checking the anode rod
  
• Cleaning burners (gas units)
  

Rheem simplifies this with their EcoNet app, which can send reminders and alerts. Some models also include built-in leak sensors.

AO Smith models don’t always offer the same smart reminders but are built for longevity. Their commercial-grade components typically need less frequent service, especially in high-efficiency or hybrid units.

Verdict: Rheem offers easier maintenance and better user communication, while AO Smith units tend to require fewer repairs over time due to higher-grade parts.

Smart Features & Connectivity

Price and Value for Money

Initial Cost of Units

When comparing similar models head-to-head, Rheem tends to be more affordable, especially at retail:

• Rheem tank models: $400–$1,000
  
• AO Smith tank models: $500–$1,200
  

For tankless and hybrid models:

• Rheem tankless: $700–$2,000
  
• AO Smith tankless: $900–$2,500
  
• Rheem hybrid: $1,200–$2,000
  
• AO Smith hybrid: $1,500–$2,800
  

AO Smith generally positions itself as a mid- to high-tier brand, while Rheem offers a broader price range with more entry-level options.

READ MORE: What Size Tankless Water Heater Do I Need?

Installation Costs

Professional installation fees are similar for both brands, but since AO Smith models are often installed by contractors, they may come with higher labor costs. Rheem models from Home Depot may include flat-rate installation packages, making the process more predictable.

Long-Term Operating Costs

AO Smith may have higher upfront costs, but their units often last longer and cost less to run, especially in hybrid and high-efficiency models. Rheem is more accessible and affordable initially but may require slightly more frequent maintenance depending on the model.

Verdict: For budget-conscious buyers, Rheem wins. For those thinking long-term in terms of efficiency and longevity, AO Smith delivers more value over time.

Pros & Cons Summary Table

Customer Reviews and Satisfaction

What Homeowners Are Saying

When it comes to customer feedback, both AO Smith and Rheem receive solid marks—but for slightly different reasons.

AO Smith is often praised for:

• Durability and longevity – Users report systems lasting well beyond the 10-year mark.
  
• Quiet operation – Especially in hybrid and electric models.
  
• Consistent hot water supply – With few complaints about running out, even in large households.
  

Homeowners who opt for AO Smith tend to be more experienced or working with a contractor. As such, reviews often come from those who appreciate reliability and build quality, especially for larger homes or higher hot water demand.

Rheem is frequently lauded for:

• Affordability and ease of purchase – Easy to find at Home Depot or Lowe’s.
  
• User-friendly controls – Especially models with digital thermostats and the EcoNet app.
  
• Quick installation – Both for DIYers and pros.
  

Many Rheem users mention the value for money and the variety of models available for every budget. However, a few users note minor issues like leaking fittings or difficulty finding replacement parts on older models.

Common Complaints and Praise

Both brands have extensive customer service departments, though AO Smith is often preferred by professionals due to their deeper technical support and documentation.

Verdict: For professional-grade quality and fewer issues long-term, AO Smith stands out. For ease of access, lower cost, and smart features, Rheem wins consumer favor.

Availability and Accessibility

Where to Buy

Here’s where the buying experience really differs.

Rheem is heavily featured in:

• Home Depot
  
• Lowe’s
  
• Amazon
  
• Online retailers and local hardware stores
  

This makes it incredibly convenient for the average homeowner to browse, compare, and buy without involving a contractor.

AO Smith is mostly sold through:

• Plumbing supply stores
  
• Wholesale distributors
  
• Contractors and installers
  

While you can find AO Smith units at certain Lowe’s locations, the best selection is through professional channels.

Verdict: Rheem is more DIY-friendly and widely available to the average consumer. AO Smith is best accessed via pros, which can increase quality but reduce convenience.

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Which Water Heater Is Best for You?

Best for Budget Buyers

If you’re working with a tight budget and want a solid water heater that’s easy to install and maintain, Rheem is the clear winner. Their broad range of options—from basic tank models to smart hybrids—makes it easy to find something under budget without sacrificing too much quality.

• Easy to purchase
  
• Simple to install
  
• Wide price range
  

Best for Energy Efficiency

If your goal is long-term savings through energy efficiency, both brands offer solid contenders—but AO Smith takes the crown with its high UEF-rated Voltex hybrids and high-efficiency tankless systems.

• Commercial-grade heat exchangers
  
• Exceptional UEF ratings
  
• Lower operating costs over time
  

Best for Long-Term Investment

If you’re planning to stay in your home for the long haul and want a heater that will last 10+ years with minimal issues, AO Smith’s superior durability and build quality give it the edge.

• Higher-grade materials
  
• Extended warranties
  
• Preferred by contractors for reliability
  

Summary Verdict:

Conclusion

When it comes down to choosing between AO Smith and Rheem, there’s no one-size-fits-all answer—it all depends on what you value most.

If you’re looking for a budget-friendly, user-friendly, and tech-savvy solution, Rheem has an edge. It’s easier to buy, install, and manage, especially for the everyday homeowner or a DIY enthusiast. Their smart features and wide availability make them a solid choice for smaller homes and moderate usage.

On the other hand, AO Smith offers superior performance, durability, and long-term value. It’s the better option for large households, long-term homeowners, or those working with a professional. With a stronger focus on energy efficiency and high-demand applications, AO Smith is ideal if you’re looking to invest in a water heater built to last.

Whichever brand you choose, make sure it fits your home’s size, hot water demand, and installation preferences. And don’t forget—proper maintenance and timely inspections will ensure your water heater serves you well for years to come.

FAQs

1. Which brand lasts longer, AO Smith or Rheem?

AO Smith models are generally built with higher-quality materials and tend to have a longer lifespan, especially in hard water areas or high-demand households.

2. Are AO Smith water heaters made in the USA?

Yes, many AO Smith water heaters are made in the USA, with major manufacturing facilities located in Tennessee and Kentucky.

3. Is Rheem better for electric water heaters?

Rheem offers excellent electric water heaters, especially for DIY buyers. Their models are often easier to install and come with smart controls like the EcoNet system.

4. Can I install an AO Smith or Rheem unit myself?

Yes, but Rheem is generally more DIY-friendly. AO Smith units are often designed for professional installation and may require more specific setup or parts.

5. Which is more energy-efficient, Rheem or AO Smith?

Both brands offer ENERGY STAR® certified models, but AO Smith has a slight advantage in hybrid and high-efficiency tankless categories with higher UEF ratings.