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Rheem vs. AO Smith Comparison – What is the Best Water Heater?

Rheem and AO Smith are two of the most popular water heater companies in the US. Both offer a wide range of different water heaters for smaller and bigger households and models that are powered both by electricity and gas.

It’s only natural to wonder if Rheem might be better than AO Smith since it costs more. However, there are many other things that should be considered when selecting a new water heater besides brand name alone. If you’re in the market for a new hot water heater, here’s what you need to know to make an informed decision on which is best for your family.

It’s not surprising that both Rheem and AO Smith are among the top-selling brands at Lowe’s, Home Depot, Menard’s or any other home hardware store or major retailer. Both offer reliable models that homeowners can count on to heat water and provide hot showers. That said, there are differences between the two brands that can help you determine which is best for your home.

Both Rheem and AO Smith make a great product. If you go by online reviews, many will say they love both their AO Smith water heater and their Rheem water heater. The reason to choose one over the other often comes down to price. Consumers typically choose the lower-priced unit over a more expensive model from either company.

But, which one is the best for you?

Rheem vs. AO Smith – Which One is Better?

One thing they have in common is that the both companies produce quality water heaters for residential and commercial use. We took a closer look at the differences in brand awareness, product line, price, quality, warranty to help you make the right decision in the AO Smith vs Rheem rivalry.

Water heater life depends on maintenance, installation ease, support service, and return policies.

First off, AO Smith is solely focused on the water heaters while Rheem has a broader range of products including air conditioning, heating, and cooling systems.

AO Smith Water HeatersGenerally, AO Smith water heaters are the preferred choice of many plumbers and it speaks thousands of words. AO Smith’s solid reputation comes from owners and plumbers of the US-made tools seeing them replaced only after 30+ years of service.

That said, they are of a very high-quality and should last you a while. AO Smith offers an up-to-12-year warranty on most models, which is unmatched by some rivals. AO Smith also has a very extensive portfolio of heaters and it should be easy to find one that fits your needs best.

rheem water heatersRheem water heaters have been available to the general public for almost 100 years. They also offer a comprehensive variety of different water heaters and are known to be of very high quality and very practical as well. However, while AO Smith is known for its customer service, Rheem is not.

This is very important for water heaters, as you wouldn’t want to be left without warm water for longer than one day. Rheem is a good, mid-level water heater brand that’s not too costly. Its reputation for manufacturing durable, reliable water heaters makes it a good choice for most homes.

Rheem water heaters are medium-priced water heaters that are designed to last. They are made in China, which is not necessarily a bad thing because of the high quality of manufacturing there. Lots of people prefer the mid-level option that Rheem offers because it provides them with a solid combination of dependability and affordability.

While AO Smith and Rheem offer comparable warranties (12 years on most products), if you want to be absolutely sure to have no issues with your water heater for at least four decades, we suggest going with an older brand such as Bradford White or Richmond.

The $399 to $599 price range means the units sold by both companies should be well within reach for most homeowners. Both companies are known for producing very reliable products that will last you for years.

Our Opinion
Overall, AO Smith is probably the better choice for gas water heaters, but only by a fraction. You should still be well served by Rheem if you take care of it regularly. Rheem is the major player in the US amongst Electric Tankless Water Heaters with a market share of 22%.

Is AO Smith a good water heater ?

The ao smith water heater is one of the top brands, but it is not right for everyone. It’s important to consider how you will be using your water heater before buying one, because different models have different features.

Generally a ao smith water heater is reliable and has good reviews from previous buyers. However, it is possible to find a better water heater that meets your needs.

If you want a reliable water heater that performs well, the AO Smith is a good choice. This brand is known for being tough and long lasting . It has worked well in different weather conditions without rusting, staining or corroding.

Some of them have included features that allow you to reduce energy usage when it’s not necessary. These heaters are also reasonably priced. However, some models do not work at high altitudes.

Is Rheem a good water heater?

Rheem is one of the most common brands of water heaters in America. Rheem offers a wide range of electric heaters for homes and businesses, including gas-powered tankless models. The durability, reliability and efficiency of Rheem products have made them popular with homeowners looking to save money on their energy bills while prolonging their heater’s lifespan.

The main complaint about Rheem is that it costs too much compared to other brands. However, it could be worth the extra cost when considering the Manufacturer’s Warranty provided by Rheem – which can last up to 12 years or longer! Many people feel this warranty provides peace of mind in knowing they are protected against repairs for many years down the road should they encounter difficulties.

Rheem is simple to install, even for non-plumbers. It also makes no noise which means you can go about your daily business without worrying about the water heating up.

The only downside of Rheem heater is that they are large and bulky so do not fit well in small spaces or where the user wants to save space (such as apartments). You should ensure that enough ceiling height exists for installation purposes. Ensure that if you have low ceilings that engineered wood beams be checked for structural integrity before attempting any installation work.

How much do Ao Smith Water Heaters Cost?

Ao smith water heaters cover a wide range of prices. The price depends on the features you want and your location. Generally, a mid-range ao smith water heater costs around $300 or more. This price is for a standard electric water heater. There are also natural gas and propane models that cost more. The cheapest ao smith water heaters cost around $200. However, these tanks do not have an energy factor greater than 0.60 or an energy factor of 2.0 or higher

The most expensive ao smith tankless water heaters cost upwards of $1800 depending on the features and size desired by the customer such as resettable breakers and digital metering technology as opposed to mechanical meters found on some models.

How much do Rheem Water Heaters Cost?

The cost of Rheem water heaters varies widely, depending on the size and type that you choose. The price for this highly popular brand ranges from $500 to almost $2,000 for an electric model or natural gas unit. Hybrid models come at similar prices but lack some of the features like tankless heating. Upgrades include glass lining (to prevent corrosion), which will cost up to $200 extra; stainless steel options are more expensive at around $1,500; and higher energy efficient units can hit up to $3,000 in total costs.

A high-efficiency electric Rheem tankless heater is available for under $1,000 (May 2017). A 40-gallon power vent type retails for $800 and a 50-gallon model can even be found for just $400. A gas heater that is Energy Star-rated costs between $1,500 to $2,000.

How long do Ao Smith Water Heaters Last?

Ao Smith lasts anywhere from 13-20 years with proper maintenance and care, even longer if you live in an area where there is low mineral content in your water supply.

How long does Rheem Water Heaters Last?

A Rheem water heater can last up to 20 years if well maintained and used properly. Most units come with a one year warranty which covers manufacturing defects and labor costs involved in putting your heater together and installing it at the location of your choice. The best way to make you water heater work for longer is by checking its flammable vapors sensor, anode rod, drain valve, pressure relief valve, thermopile (heat sensor), relief tube/port fitting every six months for cracks or leaks and tightening all nuts that secure the unit into place.

Beware that there is no warranty for the pressure relief valve.

What are some Top AO Smith Water Heater Features?

The ao smith electric water heater is made in the United States and has good reviews. A lot of models come with an electric tank, digital display and a built-in thermostat.

Ao Smith gas water heaters also have good reviews; however, some people do not like that they are made in China. A mid-range model costs around $400 or more.

AO Smith Features:

  • Limited Lifetime Warranty on tank
  • 12-year warranty on glass lining
  • 10 year warranty on heating elements
  • 6 year warranty on remaining parts
  • 120% of rated energy output guarantee for first 10 years, then 100%

AO Smith Pros:

  • Reputation for high-quality products with great dependability
  • Very flexible product line
  • Very good customer service

AO Smith Cons:

  • Somewhat expensive water heaters
  • No corrosion-resistant options
  • So-so heating efficiency

Rheem Features:

  • 12 year warranty on tank and parts
  • Limited 7 year warranty on glass lining
  • No transferable warranty

Rheem Pros:

  • Very affordable water heaters that are well within reach for most homeowners.
  • High-end delivery valves, reliability and corrosion-resistant materials used in construction.

Rheem Cons:

  • Slightly worse heating efficiency when compared to other brands in the industry.
  • Availability of corrosion-resistant models is limited.

Rheem vs. AO Smith – Product Line

Read on to learn about the different types of water heaters, and have a look at what these companies have to offer in their portfolios.

Gas Tanked & Tankless Water Heaters

🏆 Winner: AO Smith

According to consumer reports, 37% of households prefer AO Smith gas tanked water heaters against 22% going with Rheem.

The complete A. O. Smith line of natural gas and liquid propane tank water heaters comprise around 60 different models while the Rheem brand has developed a line of 43 models.

Gas Tanked Best Sellers

In 2010, A. O. Smith introduced its full line of natural gas and propane tankless water heaters – 38 models against 10 models from Rheem.

Gas Tankless Best Sellers

Electric Storage & Tankless Water Heaters

🏆 Winner: Rheem

You definitely cannot go wrong with the Rheem electric water heater. It is a professional choice for homeowners who do not want to tend to leaky water heaters year-round even though AO Smith has a wider range of models in this category.

Both companies offer ENERGY STAR-certified products that are efficient and help reduce energy bills. However, some AO Smith water heaters may use up to 30% less energy than comparable Rheem models. That’s because they use gas more efficiently and meet new regulations for pool and spa water heaters (some manufacturers of home hot water heaters believe the regulations will become stricter over time).

Electric Tankless Best Sellers

In the category of Hybrid Heat Pump Water Heaters AO Smith and Rheem are both a great deal capable of saving money on bills for electricity and boasting of good recovery time.

Rheem vs. AO Smith – BTU Capacities

Some Rheem models have a higher maximum BTU rating than AO Smith products. That means they’re capable of producing more hot water, albeit at a slightly lower flow rate, which is better suited for larger homes with multiple fixtures. On the other hand, some AO Smith models are designed to be smaller and more compact because their flow rates are faster.

Tank Design & Construction Differences

🏆 Winner: Rheem

Browsing online reviews on the specialized plumber’s forums, we have seen a few people complaining about AO Smith’s faulty design. Though, to be honest, both brands look similar in terms of gas heaters design through Rheem’s styling looks a bit more varied and modern in the category of electric water tanked heaters.

The construction materials of Rheem tanks are thicker than those used by many of their competitors. Some say this makes them more resistant to rusting over time, but that may not necessarily be true since corrosion can still happen if any part of the tank is exposed to the elements. AO Smith tanks, on the other hand, are often made of cheaper materials that can become brittle over time.

Warranty & Support

🏆 Winner: AO Smith

Both companies offer great warranties on their tank water heaters (and even better warranties for hybrid heaters). However, Rheem provides a more comprehensive warranty than some lower-priced competitors including AO Smith. This is especially true when it comes to heating elements. That means you get the longest possible protection against leaks and cracks with Rheem products compared to similar models from other manufacturers.

AO Smith and Rheem products were built to last. But even the best products can be affected by outside factors like wear, air or water conditions, environmental concerns, and yes, even issues in the manufacturing process.

AO Smith water heaters on average have a warranty of six to 10 years while Rheem often promises an extended 12-year warranty for tanks.

Rheem water heater models are also offered with Limited Warranties varying from six (6) years to as long as the original purchaser owns the home in which the unit is installed.

From what we have seen after analyzing tons of consumer reviews, Rheem has weaker support regarding the ease of reaching them and fixing the issues should they arise.

Rheem vs. AO Smith – Price Differences

The prices of many models from these companies are similar enough that the decision may come down simply to brand loyalty or availability in local stores rather than any major distinction in quality. However, some AO Smith models can be 20% to 25% less than similar Rheem models. So if you don’t want to spend the extra money on a Rheem model, get an AO Smith.

Rheem vs. AO Smith – General Recommendations

It’s best to go with either Rheem or AO Smith based on your budget and the size of your household (bigger homes need more hot water, so they generally require larger tank sizes). Then focus on warranty coverage and energy efficiency.   If one brand’s warranty is more comprehensive than another’s, that may be the best choice even if it means paying a little bit more.


Overall, AO Smith is probably the better choice for gas water heaters, but only by a fraction. You should still be well served by Rheem if you take care of it regularly. Rheem is the major player in the US amongst Electric Tankless Water Heaters with a market share of 22%.

Both Rheem and AO Smith are top brands with many similar models. However, there are some key differences that can help you make the best choice for your home. When it comes to price, energy use, BTU capacities, warranty coverage and other features like tank construction materials and heating element protection, Rheem usually provides better performance (and thus more value) than AO Smith. However, if you’re on a tight budget or don’t need as much hot water for your household of three people or fewer, an AO Smith may do the job just fine at a lower cost.

What’s the Best Type of Water Heater for Your Household?

Warm water was once a luxurious thing not available to the masses, but today it’s almost a human right to have it. With that said, there are several ways to add warm water to your apartment or house, with a central water heater being the most popular one.

water heater types

These water heaters are the most efficient because they provide warm water for the whole apartment or house. With a high-quality water heater, you can take a shower and clean the dishes at the same time, and there will still be some warm water left.

There are a lot of different water heater types and models available on the market right now. While that’s great for innovation and price, it can be hard to make a choice just by looking at the specifications.

The first thing you should do is to decide between electricity and natural gas. Water heaters that work on electricity are less expensive to buy, but they can be more costly in the long run. Also, every household has electricity but doesn’t necessarily have gas. On the contrary, natural gas water heaters are more expensive to buy, but they will cost less in the future due to the lower price of gas when compared to electricity.

Then, you should decide on what type of water heater you need. Here are all the classifications:

  • Storage water tank heater – this type consists of an insulated tank and a water heating element. When the storage tank water heater achieves a certain temperature, it stops working. This one is recommended for bigger households;
  • Tankless Water Heater – heats the water when you need it. Given the fact that they don’t store the hot water and only use power when you need it, they are more efficient. However, they can’t heat a lot of water at a time and thus are not suitable for bigger households;

    Best Tankless Gas Water Heater

  • Heat Pump or Hybrid Water Heater – captures the heat from the air and uses it to heat the water. Also very efficient, but more expensive as well. Besides, they don’t work in cold spaces;

    Best Electric Heat Pump Water Heater

  • Condensing Water Heater – uses the exhaust gasses from the burning of the natural gas, which makes them more efficient. They are great for very big households.

    Best Condensing Water Heater

Rheem in spotlight

Rheem LogoFounded in 1925, Rheem is among the largest manufacturers in the North American water heating market. Rheem is headquartered in Atlanta and has spread its presence into 14 countries. The company’s most famous water heater brands embrace Rheem, Ruud, Richmond, EcoSmart and many others.

The company sells water heater models in gas, electric, tankless, solar and hybrid styles. You can control or monitor it as part of your smart home using the included EcoNet Wi-Fi Kit and smartphone app. This EcoNet system can even send you alerts if there is a leak or other complication. To protect you, the device automatically turns off if potentially flammable vapor builds up. You won’t have to worry about cleaning a filter either, as this unit is made to operate without one.

A.O. Smith brief information

AO Smith LogoAO Smith used to be the preferred choice of plumbers before they moved their production to Mexico in 1996 to reduce the manufacturing costs. Present-day Mexico-made AO Smith water heaters are still good but cannot compete against their ancestors in terms of longevity.

Additionally, the original AO Smith water heaters’ quality was further questioned after they acquired the Whirlpool brand and started selling their models under the AO Smith label.

Producing residential water heaters since 1939, AO Smith company now serves the water heating needs of people in 60 countries through a bunch of brands like American Water Heaters, Aquasana, GSW, Hague, John Wood, Lochinvar, Reliance, State Water Heaters, Takagi, and U.S. Craftmaster.

AO Smith patented a glass-lined brewery tank back in 1933 to become the industry standard.

The popularity of A.O. Smith vs Rheem in the U.S.

Assessing the popularity of AO Smith vs Rheem brands we have reverted to a couple of methodologies backed by the statistics from the open sources.

We are inclined to think that sales numbers are the eloquent indicator of popularity.

A survey, conducted by the Energy Star in 2018, concluded AO Smith and Rheem dominate the residential water heaters market in the U.S.

A.O. Smith accounted for 40 percent of residential water heater shipments while Rheem had a share of 33%.

AO Smith vs Rheem residential water heaters market share

Easy to install and Value for money

Statista survey has put A.O. Smith to be the most used water heater brand among construction firms in the United States in 2018. In the same report, 10.6 percent of the respondents used Rheem brand water heaters.

Brand of water heater used the most by construction firms in the United States in 2018

Brand of water heater used the most by construction firms

Alternatively, we have checked out the popularity of both brands from the perspective of water heaters in Google Trends.

It seems that ordinary people google for Rheem more frequently rather than A.O. Smith. Over the last year, customers were searching extensively for A.O. Smith recalls and water heater reviews and Rheem top searches were related to tech support.

What is the best Rheem gas water heater?

If you are pressed for time but need a quick tip on the best performing Rheem gas water heater, we suggest you pay attention to their Professional Prestige line. The Rheem models in this group comprise Energy Star tankless and storage gas water heaters with an extended 12-year warranty equipped with such cool features like condensing tech, self-cleaning system, an improved self-diagnostic system, high First Hour Rating.

3 thoughts on “Rheem vs. AO Smith Comparison – What is the Best Water Heater?

  1. Ao smith mops the floor with rheem. I am a professional installer of plumbing in new jersey. Ao smith bought out state water heaters. Who had been around for a really long time. Actually, 2021 and still taking out old state water heaters. Even still sometimes repairing them. Rheem water heaters are bottom of the line for water heaters. Cant even put a number on how many rheems i have taken out before or just after there warranty period. Never have any issue with an ao smith.

  2. I bought An AO Smith 50g tank heater in 2010. Started leaking just under the 6 year warranty. Replaced under warranty. The replacement was only warranted for the remainder of time on the first warranty. The replacement just started leaking at 5 years 2 months. I don’t consider that a long lasting product.

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