Water Heaters

AO Smith vs Rheem – Water Heater Comparison

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AO Smith and Rheem are two of the most popular water heater brands on the market. Both brands offer a wide variety of water heaters to choose from, so it can be tough to decide which one is right for you.

In this article, we’ll compare AO Smith and Rheem water heaters to help you decide which brand is best for your needs. So, let’s begin

AO Smith VS Rheem – A Comparison

AO Smith vs Rheem

Company Reputation and Track Record

A Brief History of AO Smith

A. O. Smith is a water heater manufacturer corporation founded in Milwaukee, Wisconsin. The company specializes in the design, production, and marketing of water heaters and HVAC (heating, ventilation, and air conditioning) products for residential and commercial applications. The company was founded back in 1904 by Aurthur Oliver Smith and has been one of the leaders in the water heater industry ever since.

A Brief History of Rheem

Rheem Manufacturing Company was founded in Richmond, California, in 1925 by Richard “R. S.” Rheem and his brother Donald “D. L.” Rheem. The company started out as a small, family-owned business and has since grown into one of the largest manufacturers of residential and commercial water heaters in the world.

Both AO Smith and Rheem have a long history of producing quality water heaters. However, when it comes to overall company reputation, AO Smith is the clear winner. AO Smith has a long history of producing reliable water heaters, approximately 100 years which makes it a century. Whereas, when it comes to Rheem, even though it has been in business for quite a long too, yet it has spent comparatively 25 years lesser in the market than that of A.O. Smith.

Comparison Between Features and Functionality


When it comes to performance, AO Smith and Rheem both offer a wide variety of water heaters for different needs. However, the energy efficiency varies from product to product depending on how they are engineered and what features they have. Generally, Rheem water heaters tend to be more efficient than those of AO Smith, but this will vary depending on the model.

AO Smith offers a wide range of water heaters with varying tank sizes and efficiency levels to fit your heating needs. Rheem also offers many different models which are available in multiple sizes with similar features across each series, including ENERGY STAR compliant models.

Costs and Affordability: 

A.O. Smith water heaters tend to be less expensive than Rheem water heaters. However, the reason for Rheem being an expensive brand is that it offers smart technology as well as solar options. Whereas, A.O Smith unites May be cheaper, but they don’t offer as many options when compared against Rheem models; yet they’re still widely accessible due largely because most plumbing stores carry them.

Quality and Reliability: 

Both the brands claim to offer some of the highest-quality water heaters on the market. AO Smith offers a wide range of tank models, some with advanced features designed for extra durability and efficiency. 

Rheem also provides many different models that are built to last with advanced features that can save you money over time. However, when it comes to the point that which one offers better quality products than the other, we must say that Rheem takes the trophy home. 

AO Smith is a well-known, reliable brand for water heaters. However, over time Rheem has become known as one of the most reliable brands for both residential and commercial water heaters. They offer a wide range of models that come with a variety of features, making it easy to find the perfect water heater for everyone’s needs.

Energy Efficiency: 

This one is quite difficult to answer as both the brands maintain their efficiency standards well enough, but Rheem has an edge over AO Smith water heaters due to it being more up-to-date with advanced technology.

Rheem units are ENERGY STAR certified, which means they meet strict guidelines set by the United States Department of Energy to ensure that you’re receiving a highly-efficient product. AO Smith units aren’t Energy Star certified, but they offer an array of tank sizes that allow you to find the right fit for your space and energy needs.

Safety Features: 

Even though both brands have many of the same safety features, but we have to say that A.O. Smith wins the race here. it features advanced safety features that are not found in other models of various brands

AO Smith offers a variety of different models that come with several advanced safety features, such as an automatic shut-off valve and a low-water cutoff switch. Rheem also has many different models with similar safety features, but they may not be as advanced as those found in AO Smith models.

Installation and Ease of Use: 

When it comes to users’ convenience, AO Smith water heaters stand out. AO Smith units are easier to install, allowing the average homeowner to do it themselves rather than having to hire a professional. Plus, it can be installed anywhere in the house.

It also comes with clear instructions that are easy to follow and understand. Rheem’s installation instructions aren’t quite as straightforward or detailed, but their manual is still relatively easy to follow.

Both brands offer a variety of models with different installation options, so you can find the perfect one for your needs. However, AO Smith is the clear winner when it comes to user convenience.

Required Space: 

We can say that it’s a tie here, as both brands have a wide range of tank sizes that can fit in a variety of spaces

When it comes to the amount of space required, both brands have a variety of different tank sizes that can fit in a range of spaces. This makes it easy to find the perfect water heater for your needs, regardless of the size of your home or garage.


Here, AO Smith takes it home without much of a problem. AO Smith offers several models with different tank sizes and colors, so you can easily find the perfect match for your home’s exterior décor. Rheem also has many options to choose from in terms of color and style, but they aren’t as customizable or numerous as those found in AO Smith units.


AO Smith has one of the best warranties on the market, while Rheem is very close behind. AO Smith units come with a 10-year limited warranty that covers materials and workmanship errors for all components except the heat exchanger. The heat exchanger only comes with a three-year warranty.

Rheem units, on the other hand, feature a relatively limited lifetime warranty (approximately 9 years) on the heat exchanger out of which only 3 years cover the full-time warranty. This puts Rheem at a close second to AO Smith when it comes to warranty coverage.

Types of Water Heater – Which One offers the Best Types?

Electric Water Heater: 

When it comes to electric heaters, AO Smith is the clear winner because it has extra features like a double copper heating element and a concealed heating element that enables it to heat water more quickly than most other models. Moreover, it also offers almost 30 different models of electric heater whereas Rheem, on the other hand, is only able to provide 20+ models of the electric heater by now.

Gas Water Heater: 

Again, for the gas ones, AO Smith wins the race one more time because the gas heaters of this company come in approximately 60 different models while that of Rheem are only available in 40 variations. What adds more to it is that AO Smith uses natural gas as well as liquid propane in some of their models.

Tankless Water Heater:

For the Tankless water heaters, we’ll have to say that Rheem takes all the scores from here by featuring 35+ models of these heaters and becoming one of the recognizable names in the market for their tankless heaters. While on the other hand, AO Smith, which is not quite popular for its tankless heaters only features 20 models of them, thus letting the Rheem take the numbers.

A Few Notable Products from A.O. Smith

A.O. SMITH 9003542005 Water Heater FV Pilot, 190-Degree C, Natural

A.O. SMITH 9003542005 Water Heater
257 Reviews
A.O. SMITH 9003542005 Water Heater
  • 9003542 natural gas pilot assembly, works on the following water heater
  • This product adds a great value

If you’re looking for a replacement natural gas pilot assembly for your A.O. Smith water heater, we’ve got just what you need. This 190-degree C model is compatible with the following water heater models of the AO Smith brand: 9003542005, 6-30-yours, 6-30-yours-d, and a few more.

This natural gas pilot assembly is perfect for your A.O. SMITH water heaters. With a temperature setting of 190°, this assembly is just what you need to keep your water heater to the perfect temperature. This clever little product is easy to install and comes with easy-to-follow installation instructions. Simply match the corresponding tag on the original pilot assembly to find the right one for your new unit! The corresponding tag on the original pilot assembly makes installation a breeze.

This FV Pilot is manufactured in china so you know that you’re getting a quality product. The AO Smith 9003542005 Water Heater FV Pilot is also backed by a one-year limited warranty, just in case something goes wrong with your unit. So, what are you waiting for? Order your replacement natural gas pilot assembly today!

A.O. Smith by Honeywell Gas Control Valve 100262939 2″ Cavity Natural

A.O. Smith by Honeywell Gas Control Valve 100262939 2
378 Reviews
A.O. Smith by Honeywell Gas Control Valve 100262939 2
  • Salt-Free Scale Prevention - The AO-WH-DSCLR naturally reduces scale build up in pipes and...
  • Works For All Your Water Needs - System works effectively on water for use in drinking,...

Need a new gas control valve for your hot water heater? Look no further than A.O. Smith by Honeywell! This handy little device comes with an LED status indicator that monitors system operation, making it the perfect choice for anyone looking for added peace of mind. 

Best of all, there’s no external power source needed – the thermopile generates all the power you need to operate the electronic gas control. Installation is a breeze, too – just follow the simple instructions and you’ll be up and running in no time.

The AO Smith Gas Control Valve is made with quality materials, making it a great replacement part for your water heater. This handy little device comes with a 3-year limited warranty. 

This high-quality product has been certified by a third party to be compliant with all the necessary regulations, so you can rest assured knowing your water is safe. Plus, it’s made from durable materials that will withstand the test of time, making it a wise investment for your home or business. 

This gas control valve is compatible with a variety of A.O. Smith branded heaters, making it the perfect choice for any homeowner looking for a quick and easy upgrade. With a simple installation process, you’ll be able to enjoy all the benefits of this intuitive gas control valve in no time!

AO Smith Whole House Salt-Free Water Descaler

AO Smith Whole House Salt-Free Water Descaler
39,651 Reviews
AO Smith Whole House Salt-Free Water Descaler
  • 20-Micron Hose Filter: Our GAC (Granular Activated Carbon) camper water filter reduces bad...
  • Secure Installation: This RV water filter system features a flexible hose protector that...

Do you want to prevent scale build-up in your pipes without all the cleaning and hassle? Then we recommend trying AO Smith Water Descaler, a non-toxic formula that works fast to eliminate stubborn limescale build-up.

This innovative product uses a salt & chemical-free system to reduce scaling, meaning you can enjoy clean, clear water without any of the hassles. Plus, there’s no cleaning or backwashing required – just plug it in and let it do its thing. Sounds easy enough!

This system is perfect for households of four or more people, as it effectively removes scale build-up from drinking, cooking, showering, and bathing water. What’s more is that it won’t reduce TDS (total dissolved solids), sulfur or iron levels in your water supply. 

You’ll be amazed that this ingenious device is engineered to work with both well and city water systems, making it the perfect choice for anyone looking to improve their water quality. It’s also salt-free, so you can rest assured that your family’s health won’t be compromised in any way.

This long-lasting and cost-efficient descaler reduces scale build-up for up to 6 years or 600,000 gallons. Plus, it comes with a 6-year warranty. So whether you’re dealing with a calcium build-up or magnesium deposits, the whole house Descaler is here to help.

A Few Notable Products From Rheem

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater
1,172 Reviews
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater
  • External digital thermostatic control with LED display (+/1 degree accuracy)
  • Most advanced self-modulation, adjust power to meet hot water demand

Looking to keep your plants well hydrated during those hot summer months? This bad boy is capable of heating up to 7 gallons of water at once, perfect for large greenhouses, grow tents, or small houses. 

The Rheem RTEX-18 tankless water heater is perfect for homes with up to three bathrooms. Featuring external digital thermostatic control and LED display, this system ensures pinpoint accuracy (+/1 degree) for your ideal temperature.

This advanced unit features self-modulation, so it adjusts power to meet your household’s hot water demand. Plus, with its durable copper immersion elements and field serviceable design, this water heater is built to last. The flow rate of up to 4.4 GPM makes it perfect for larger households.

This sleek and efficient unit installs easily, with bottom 3/4 inch NPT water connections and threaded fittings for simple replacement. The digital temperature display ensures accurate temperature readings, while the auto-shutoff feature keeps your home safe and energy-efficient. So why wait, Give your home the gift of never-ending hot showers with the Rheem RTEX-18!

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
1,000 Reviews
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
  • External adjustable digital thermostatic control with LED display (+/1 degree accuracy
  • Durable Copper immersion two heating elements, field Serviceable.Self-modulating power...

Are you in search of a water heater that can keep up with your demanding lifestyle? Then Rheem 240V Heating Chamber RTEX-13 is the one you need. This unit is capable of delivering 240V of heating power, so you can enjoy endless hot showers and baths without ever having to worry about running out of steam. 

With its external adjustable digital thermostatic control, you’ll be able to get pinpoint accuracy when it comes to your desired water temperature. Plus, the LED display accompanying it makes it easy to keep track of things even in low lighting conditions.

This state-of-the-art heater features two durable copper immersion heating elements that ensure quick and even heat distribution, making it perfect for large households or commercial businesses. 

Moreover, its self-modulating power control ensures efficient energy use, so you can save money on your monthly utility bills. And thanks to its simple installation and side 1/2 inch compression water connections, this heater can be up and running in no time flat.

It’s 99.8% energy efficient, meaning you’ll save big on your monthly utility bills. Plus, it has external controls so you can adjust the temperature in increments of 1°F, making it easy to get just the right level of heat. 

The Water-Saver Shower Head – 1.5 GPM helps reduce water consumption, and it’s threaded for easy replacement or simple installation. Finally, the digital temperature display ensures that you’re always aware of what’s happening with your water heater. With all these features and more, the Rheem 240V Heating Chamber RTEX-13 is perfect for homes with a high demand for hot water.

Rheem Prestige High-Efficiency 9.5GPM Indoor Natural Gas Tankless Water Heater

Rheem Prestige High-Efficiency 9.5GPM Indoor Natural Gas Tankless Water Heater
57 Reviews
Rheem Prestige High-Efficiency 9.5GPM Indoor Natural Gas Tankless Water Heater
  • Exclusive Water Savings technology conserving up to 1, 100 gallons per year
  • 199, 900 BTU (gas consumed per hour)

Last but not least, the Rheem Prestige High-Efficiency Natural Gas Tankless Water Heater is the unit that you need if you are just sick of those heavy bills that make their way into your house.

With exclusive Water Savings technology, you can conserve up to 1, 100 gallons of water per year – that’s enough to take a luxurious hot bath every day for a month!

This top-of-the-line tankless water heater features exclusive Hot Start Programming, which minimizes cold water bursts by staying in a ready-fire state. Plus, with its 199,900 BTU (gas consumed per hour), this unit delivers all the power you need to get through even the busiest days. 

The Rheem Natural Gas Tankless Water Heater is perfect for families with high water needs. Its recirculation pump ready kit means you can get hot water to all those hard-to-reach places in no time at all. 

keep in mind, it’s perfect for indoor use only, so make sure you have a place to install it indoors. The unit is easy to install and includes all the necessary hardware, so it’s up and running in no time flat.

Don’t wait any longer – this tankless water heater is exactly what you need to take your home’s comfort level up a notch!

A.O Smith Or Rheem – Which One Should You Go For?

Rheem and A.O Smith are two of the biggest names in water heaters, but what sets them apart from each other? Let’s take a look.

First of all, A.O Smith offers a wider range of products, from electric to gas-powered models and even heat pump systems. Rheem, on the other hand, specializes in gas-fired tankless water heaters.

A.O Smith is also a bit more affordable, making it a popular choice for those on a budget. However, Rheem’s tankless water heaters are a bit more reliable and efficient.

In the end, it all comes down to what you need. If you’re looking for a wide variety of water heater options, go with A.O Smith. If you’re looking for a reliable and efficient gas-fired tankless water heater, go with Rheem.

The Verdict

I hope you’ve found this article helpful in your search for the perfect water heater. No matter what your needs may be, there’s surely a model out there that’s perfect for you. So don’t wait any longer – take the plunge and upgrade your home’s comfort level today!

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Last update on 2022-10-04 at 09:25 / Affiliate links / Images from Amazon Product Advertising API

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