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- AO Smith Water Heater vs Rheem: A Detailed Comparison
Water heaters are essential appliances for various household purposes, especially during chilly weather. When it comes to water heaters, AO Smith and Rheem water heaters are well-known brands that manufacture high-quality products and offer a wide array of heaters from gas heaters or electric heaters to tankless or water heaters with tanks.
If you’re looking to install a water heater in your home, you might be wondering which brand is the best value for money. In this review, we’ll walk you through a detailed comparison between AO Smith water heater vs Rheem. This comparison will help you decide on choosing the best water heater that meets your hot water needs.
AO Smith Water Heater vs Rheem: A Detailed Comparison
Before getting into the comparison details of AO Smith water heater vs Rheem water heater, let’s talk about the history and background of both these companies briefly.
About Rheem

Rheem company was established in Richmond, California in 1925. At first, it started manufacturing packaging materials. But later in 1931, this company started producing water heaters when it was bought by the John Wood Company.
Now, Rheem is the leading water heater manufacturing company that produces high-quality different types of water heaters.
About AO Smith
AO Smith also has a long history of producing quality water heaters. It was established in 1874. The company manufactured bicycle parts, baby carriages, and glassed-lined brewery tanks before it started manufacturing water heaters in 1960.

Rheem and AO Smith have earned the reputation for manufacturing high-quality and reliable water heaters. Both these brands produce different types of water heaters such as electric, gas, or tankless water heaters giving their customers many options to choose from according to their needs.
Comparison Table: Ao Smith vs Rheem Water Heater
Rheem | AO Smith |
---|---|
This company manufactures efficient and high-performing electric tankless water heaters | AO Smith is famous in the water heater industry due to its large range of gas water heaters |
This company provides water heaters mainly for household rather than commercial purposes. | AO Smith brand offers high-quality water heaters for both residential and commercial purposes |
Rheem brand offers a 6-8 years warranty on its products which is less than AO Smith water heaters warranty | AO Smith provides a longer product warranty which is 6-12 years |
Rheem specializes in manufacturing a wide variety of tankless water heaters | AO Smith only produces limited models of tankless water heaters |
Rheem water heaters are a little more expensive than AO Smith products. But the price depends on the type of model you’re buying | AO Smith provides many budget-friendly water heater models |
AO Smith Vs Rheem: Comparison Performance and Features
While looking to purchase a new water heater for your home you should consider some features such as the water heater’s reliability, energy efficiency, affordability, warranty, safety features, and ease of use.
Let’s compare AO Smith vs Rheem keeping in mind the above-mentioned features and aspects.
1. Reliability
AO Smith is well-reputed in manufacturing water heaters that are made from high-quality materials and components. This aspect gives their products increased longevity. Their reliability is proven by the fact that many customers who already have an AO Smith water heater want to replace their old water heater with the same brand. AO Smith water heaters and their parts are accessible in the major centers of the country.
Rheem is also reliable for manufacturing durable and best-built quality products. Rather than using stainless steel for their water heater production, Rheem uses durable plastics that make their products lightweight and easy to install. Rheem’s units are readily available and their spare parts are widely distributed across the country.
2. Energy Efficiency
Energy efficiency is an important feature to consider while buying a water heater. An energy-efficient water heater can help you reduce your energy costs in the long run.
While AO Smith is popular for manufacturing energy-efficient and energy-saving water heaters, Rheem water heaters are better when it comes to energy efficiency. Rheem has adopted innovative designs to develop highly energy-efficient products. They also produce hybrid water heaters that include various fuel types for increased efficiency.
Rheem water heaters are also Energy Star Certified which means that Rheem units meet energy efficiency guidelines set by EPA which is the US Environmental Protection Agency.
3. Affordability
When it comes to price, Rheem water heaters are more costly than AO Smith. The reason is that Rheem water heaters provide advanced and innovative technology. They also offer many solar options for their customers.

On the other hand, AO Smith units are less expensive than Rheem models and they are readily available. AO Smith also offers a wide range of quality gas water heaters.
4. Installation and Customer Convenience
AO Smith has an edge over Rheem water heaters because AO Smith units are easy to install. They provide easy-to-understand instructions and guidelines on the installation. AO Smith also offers great customer convenience as the householders can easily install the unit on their own without the need for a professional.
5. Safety Features
Both AO Smith and Rheem water heaters provide many safety features. Many models of Rheem offer great safety features but AO Smith units have more advanced and innovative safety options that are not present in other brands of water heaters.
AO Smith units are equipped with amazing safety options such as an automatic shut-off valve and a low-water cut-off switch. Thus, when it comes to safety features, AO Smith clearly stands out.

6. Performance and Efficiency
AO Smith and Rheem both manufacture excellent quality water heaters. But if we talk about performance then Rheem is the clear winner. Depending on the type or model of water heaters, Rheem units are more efficient and effective than those of AO Smith models. Also, Rheem models are Star Energy Certified and highly energy efficient.
However, it doesn’t mean that AO Smith is less effective by any means. AO Smith company provides an array of models with different tank sizes and varying levels of efficiency to meet the household’s heating demands.
7. Warranty
Both AO Smith and Rheem offer warranties on their water heater products. Rheem provides a limited 6 to 8-year product warranty covering select parts and tank leakage.
On the other hand, AO Smith water heaters also offer a 6-12 year brand warranty that is longer than Rheem. The warranty covers tank leakage and other parts of the unit. The brand warranty has the advantage in that it offers repair of the unit or some of its parts free of cost.
Which Brand Offers Best Electric Water Heaters?
In terms of electric water heaters, AO Smith stands out as it offers incredible features that are not present in many other models. These features consist of a dual copper heating element and a concealed heating element which allows the water heater to instantly heat water.
Also, Rheem only offers almost 20 or more models of electric water heaters whereas AO provides about 30 electric heater models providing their customers a variety of options to choose from.
Which Brand of Gas Water Heaters is Best?
When it comes to gas water heaters, AO is a clear winner because this company manufactures about 60 models of gas water heaters. On the other hand, Rheem only offers 40 different types of gas heater models.
Also, AO Smith is superior with regard to gas heaters as they make use of natural gas and liquid propane in many of their gas heater models.
Which Company Offers the Best Tankless Water Heaters?

Rheem clearly wins the race when we talk about the tankless water heaters. The reason is that Rheem has become a well-reputed company in the country for their tankless water heaters. It offers approximately 35 or more different tankless heater models.
AO Smith, on the other hand, isn’t as noticeable as Rheem in terms of tankless water heaters. It only manufactures 20 different models of tankless water heaters.
Some Popular Water Heater Models of Rheem
Rheem RTEX-24 Electric Tankless Water Heater

Rheem RTEX-24 is highly energy efficient and provides instant hot water for your household needs. It has a user-friendly On/Off dial control and a programmable digital temperature display. Unlike other models, it provides a continuous supply of hot water for the entire house.
With this tankless water heater model, you can save up to 50% on energy costs. Also, this unit has a compact design and it saves a lot of storage space in your house.
Rheem Tankless water heater manuals can be found here.
RTEX-24 is highly efficient and delivers 5.9 gallons of hot water per minute (GPM). It features amazing Smart Energy Technology and only utilizes the amount of power that is needed to heat the required water. This unit can be installed easily in any place of your house and requires no venting.
Rheem Heating Chamber RTEX-13 Residential Tankless Water Heater

Rheem RTEX-13 is the popular residential tankless water heater that provides instant and continuous hot water and meets the entire home’s hot water demands. This unit is equipped with an adjustable digital thermostat as well as an LED display.
RTEX-13 features self-modulating power control and has two copper immersion heating elements that are efficient and durable. This unit is highly energy efficient and reduces your energy costs. RTEX-13 features external controls to regulate the temperature in increments of 1°F.
Some Popular AO Smith Water Heater Models
AO Smith 50 Gallon ProMax Gas Water Heater

AO Smith 50 Gallon ProMax is built to deliver ample amounts of continuous hot water for your whole family’s demands. This water heater has a Blue Diamond glass coating that provides protection from corrosion.
AO Smith 50 Gallon ProMax is equipped with a Dynaclean diffuser dip tube that is designed to decrease the accumulation of sediment and lime. This unit is energy-efficient and helps reduce your energy bills. AO Smith ProMax meets all guidelines set by NAECA (National Appliance Energy Conservation Act).
AO Smith 80 Gallon Voltex Hybrid Electric Water Heater

AO Smith Voltex Hybrid is a well-known water heater brand that can save energy costs by up to 71%. This unit features Heat Pump Technology which means that instead of using heating elements, it produces heat through heat pump technology and offers immense savings.
If you’re interested in electric water heaters, read about the 5 Best 80-Gallon Electric Water Heaters.
AO Smith 80 Gallon Voltex Hybrid comes with amazing features such as an easy-to-use display, a heavy-duty anode to increase the lifespan of your water heater’s tank, and a vacation mode to reduce energy bills when you’re away from home. This water heater meets all standards set by Northwest Energy Efficiency Alliance (NEEA). You can read about other best
Final Thoughts
We have seen that both Rheem and AO Smith water heaters have some advantages and downsides as well. Choosing a perfect water heater depends on your needs and preferences. It all comes down to what kind of water heater you’re looking for and how much you’re willing to spend on it.
If you’re looking for efficient tankless water heaters you should go for Rheem products. However, when it comes to gas water heaters, then you should definitely choose AO Smith gas water heaters. Also, AO Smith offers a longer product warranty and is a little less expensive as opposed to Rheem water heaters.
Richard is a retired HVAC specialist and air quality enthusiast! With decades of experience in the field, this author has seen it all when it comes to air-related issues and knows just what it takes to keep your surroundings clean and healthy.