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A.O. Smith Water Heater Reviews: 2024 Guide

A.O. Smith is a top water heating brand, here’s why you might choose a unit.

If you’re looking for a new water heater but don’t know which brand to choose, you might have seen the name A.O. Smith. The company is one of the oldest water heater brands in the United States and is still making heaters today.

A.O. Smith has been around since the 1870s and introduced many of the innovations that made water heaters more efficient. What is the company doing today? Is A.O. Smith a good water heater brand in the 21st Century?

To answer these questions, we have researched the company’s current offerings and written three A.O. Smith water heater reviews. After reading them, you might decide that an A.O. Smith water heater is the right option for you.

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Product Comparison Table

Product Image of the A.O. Smith Voltex® Hybrid Electric Pump
Best Hybrid
A.O. Smith Voltex® Hybrid Electric Pump
  • Energy-saving
  • User-friendly digital display
  • Heavy-duty anode rod & heating elements
Product Image of the A.O. Smith ATI-540H-N Tankless NG
Best Tankless
A.O. Smith ATI-540H-N Tankless NG
  • Commercial-grade copper alloy
  • NOx regulation complaint
  • Freeze & overheat protection
Product Image of the A.O. Smith GPVL-50 ProMax
Best Gas
A.O. Smith GPVL-50 ProMax
  • Features a hot-surface igniter
  • Glass-lined tank
  • Internal dip-tube feature

Review Methodology: At Sensible Digs, we provide you with a comprehensive analysis and assessment of the best AO Smith water heaters, ensuring you make an informed decision. Our experienced professionals conduct thorough research, hands-on testing, and compare performance benchmarks to evaluate each product from a user’s perspective. We measure and rank water heaters based on crucial factors such as energy efficiency, durability, and capacity. Additionally, we explore design choices, offering first-hand evidence and quantitative data to help you understand what sets these AO Smith heaters apart from competitors. Our in-depth review process aims to simplify your decision-making by identifying key areas of concern and scoring each product accordingly. Trust Sensible Digs to guide you in finding the ideal AO Smith water heater that meets your needs.

The Best A.O. Smith Water Heaters of 2024

As A.O. Smith is one of the innovators in the water heater industry, finding suitable products wasn’t a problem. The real challenge was narrowing them down to the top three. After a lot of research, here are our reviews of the best A.O. Smith water heaters:

A.O. Smith Voltex® Hybrid Electric Heat Pump Water Heater

Best A.O. Smith Hybrid Water Heater

A hybrid water heater is a perfect appliance for any homeowner looking to reduce their utility bills. We chose the Voltex 80-gallon electric heat pump water heater.

When it comes to cutting costs, this model delivers. A.O. Smith claims it can reduce your water heating costs by up to 71% compared to traditional heaters.

It features advanced technology that pulls the surrounding heat in while dehumidifying the remaining air. This also cools down the room.

One great feature of hybrids is their multiple user settings and the Voltex is no exception. It has hybrid, efficiency, vacation, and electric modes. You can change the settings on the digital screen, which also shows the temperature and lets you adjust it.

The digital display is very user-friendly with no more buttons than necessary. Another useful feature is the heavy-duty anode rod. This will reportedly keep your tank safe for up to 6 years.

This hybrid can provide enough hot water for simultaneous showers. Thanks to its two heating elements, the unit also has a relatively quick recovery time.


  • Highly efficient.
  • Features energy-saving settings.
  • User-friendly digital display.
  • Includes a heavy-duty anode rod and two heating elements.


  • Louder than other hybrids.
  • Might not be as effective in colder regions.

Product Specs

Uniform Energy Factor 3.45
Recovery rate Not specified
Measurements 69 inches by 27 inches by 27 inches
Energy Star Rated Yes
Warranty 6-year limited warranty on tank and parts

Our Ratings

4 / 5
Energy Efficiency
5 / 5
4 / 5
3.5 / 5
Total Rating
4 / 5

User Experience

Definitely not the best experience with this hybrid electric heat pump water heater so far. In just three years, it has stopped working multiple times, forcing me to replace it and pay for a plumber each time. Although it's still under warranty, the extra costs are really adding up, making me wish I had opted for a traditional water heater instead. I highly recommend looking into other options to save yourself from the hassle and expenses we've encountered.

A.O. Smith ATI-540H-N Tankless NG Water Heater

Best A.O. Smith Tankless Water Heater

If you have a larger household and are looking for a space-saving solution, A.O. Smith’s 540 series is excellent for residential use. We chose the ATI-540H-N tankless water heater.

Like the rest of the 540 series, this model uses commercial-grade copper alloy in its heat exchanger. This durable material is also what makes it suitable for a high-demand household. It delivers an indefinite supply of hot water to three to four bathrooms at once, depending on your local climate.

The unit is fuelled by natural gas and uses no more than 199,000 BTU per hour. It complies with the Ultra-Low NOx regulations and has a uniform energy factor of 0.93. It uses condensing technology, making it super-efficient.

The incorporated safety features include overheat and freeze protection, as well as troubleshooting codes. It also includes an Easy-Link System, meaning you can connect it with up to four other units.

This tankless water heater is fairly easy to install. A.O. Smith recommends that you mount it indoors but it can also be installed outdoors. Keep in mind that outdoor installation is only recommended if you live in a warm climate.


  • Heat exchanger fitted with commercial-grade copper alloy for durability.
  • Unit complies with the Ultra-Low NOx regulations.
  • Includes safety features such as freeze and overheat protection.
  • Can be installed indoors or outdoors.


  • Flow sensors require a higher flow to activate which may cause cold water.
  • Quite loud while working.

Product Specs

Uniform Energy Factor 0.93
Recovery rate 10 gallons per minute
Measurements 23.625 inches by 17.75 inches by 11.25 inches
Energy Star Rated Yes
Warranty 15-year heat exchanger warranty and five years on parts

Our Ratings

4.5 / 5
Energy Efficiency
4.5 / 5
4.5 / 5
4 / 5
Total Rating
4.25 / 5

Personal Perspective

I've been using this tankless water heater in my home and have experienced an endless supply of hot water, although I have to wait about a minute before it arrives. The installation process was fairly easy, requiring only minor plumbing adjustments and the use of PVC ducting for exhaust; even the exhaust fan noise is barely noticeable. I opted for this product over a traditional water heater, mainly because I was finishing my basement and wanted to ensure a continuous supply of hot water in the future. So far, it has exceeded my expectations and led to a lower utility bill.

A.O. Smith GPVL-50 ProMax Power Vent Gas

Best A.O. Smith Gas Water Heater

A.O. Smith’s gas water heaters work on either natural gas or liquid propane. We chose to review the GPVL-50 ProMax, part of the ProLine series.

This unit is excellent for a household with a higher demand for hot water. It has several useful features and functions, including its internal dip-tube.

The cold water enters through the dip-tube, which reaches down to the bottom of the tank. It puts pressure on the cold water, preventing it from influencing the temperature of the heated water. This results in less energy being wasted on reheating.

To further save energy, the unit has a hot-surface igniter instead of a pilot light. A hot-surface igniter is generally more reliable and robust than a pilot light.

The tank itself is quite durable. Instead of a standard steel tank, A.O. Smith lined theirs with glass, eliminating the risk of rust and corrosion. To top it all off, they insulated it with 2-inch thick environmentally-friendly foam to minimize standby heat loss.


  • Delivers enough hot water for a five-person household.
  • Features a robust hot-surface igniter.
  • Glass-lined tank with 2-inch thick environmentally-friendly foam insulation.


  • Some customers complained that it is too tall for a 50-gallon water heater.

Product Specs

Uniform Energy Factor 0.72
Recovery rate 79 gallons per hour
Measurements 60.1 inches by 24 inches by 24 inches
Energy Star Rated Yes
Warranty Six-year limited warranty on tank and parts

Our Ratings

4 / 5
Energy Efficiency
3.5 / 5
4 / 5
3.5 / 5
Total Rating
3.75 / 5

Community Feedback

I've recently installed this water heater, and by now, it has been working great, providing a consistent temperature stream of water. Although I felt the price was a bit high, I am overall very satisfied with the performance. In the future, I hope it lasts longer than the previous model I had, which unfortunately sprang a leak after 6 and a half years.

Product Comparison Chart

Product Award Uniform Energy Factor Recovery rate Measurements Energy Star Rated Warranty
Voltex® Hybrid Hybrid 3.45 N/A 69″ x 27″ x 27″ Yes 6-year (limited)
ATI-540H-N Tankless 0.93 60 gal/hr 23.625″ x 17.75″ x 11.25″ Yes 15-year (heat exchanger); 5 years (parts)
GPVL-50 ProMax Gas 0.72 79 gal/hr 60.1″ x 24″ x 24″ Yes 6-year (limited)

Why Choose an A.O. Smith Water Heater?

Something that is evident about A.O. Smith is that the company goes all out to help customers find their perfect unit. They provide several tools on their official website to help you find the right water heater.

If you’re looking for a specific type of heater, A.O. Smith has a wide range for both residential and commercial use.

Which A.O. Smith Water Heater Should You Choose?


A.O. Smith’s ProLine water heaters are a great fit for larger households or those living in colder regions. The company also says its heaters are designed to be suitable for use in a mobile home.

These water heaters have a very high recovery rate, with a first-hour rating of 79 gallons per hour. Most have a uniform energy factor of 70% or more. Many are even Energy Star certified.

Even so, this line isn’t as high-tech as some of A.O. Smith’s other products. The ProLine water heaters don’t have Wi-Fi compatibility or any other high-tech functions.


A.O. Smith has two lines of tankless water heaters: gas/propane and hybrid/propane. As of writing, gas/propane appears to be the more popular type.

Most of the gas/propane models are Energy Star and LEED-certified. They all have Ultra-Low NOx ratings and are very efficient.

Depending on the size of your unit, they can provide you with an indefinite flow. They would make a great addition to a three-bathroom home.


A.O. Smith’s hybrid water heaters are part of their Voltex line. These are a cross between their electric Vertex line and hybrid design.

All the models within the Voltex line are Energy Star certified. They have all the benefits of an electric boiler with the efficiency of a heat pump design. This combines to save energy and money.

The Voltex hybrid water heaters also work as dehumidifiers, drawing moisture from the surrounding air. Once inside the unit, this moisture is used to heat the water, reducing water consumption and running costs.

Despite all the positives, these units do require some extra space to work properly. If your house is on the smaller side, this line probably isn’t for you.

History of A.O. Smith

A.O. Smith is one of the oldest major water heating companies. It was founded by Charles Jeremiah Smith in 1874 but didn’t initially manufacture water heaters.

It started by making baby carriages and bicycles. The company developed a process for forming steel tubing from sheet metal to create frames for its various products. Two decades later, it was the biggest bicycle part manufacturer in North America (1).

In 1899, A.O. Smith started making frames for cars. The son of Charles Jeremiah Smith, Arthur Oliver Smith, created the first pressed steel vehicle frame.

The company soon began making frames for car manufacturers such as Cadillac, Peerless Automobile Company, and Ford Motor Company.

World War Efforts

During the First World War, A.O. Smith engineers developed a coated welding rod. This breakthrough became a major influence on the development of arc welding as a mass-production method.

A.O. Smith continued to produce military equipment during the Second World War. The company produced 16,750 sets of landing gear, 46,700 propeller blades, and even nose frames for B-25 bomber planes.

It also built 4.5 million bombs, water heaters for barracks, and jeep frames. Its staff even participated in the atomic bomb project in 1945 by building various components (2).

Water Heater Developments and Expansions

Soon after the Second World War, A.O. Smith acquired the Burkay Company of Toledo, Ohio. It was here that they officially entered the market for coil-type commercial water heaters. Five years later, A.O. Smith introduced the world to the first glass-lined commercial water heater.

At the start of the 1960s, A.O. Smith International opened a commercial water heater and boiler plant in Stratford, Canada. It was the company’s first water heater plant outside the United States.

In the early 1970s, they expanded to Europe, building a plant in Veldhoven, Netherlands. Although it was initially a sales office for Europe and the Middle East, it soon included assembly and fabrication premises.

In 1974, A.O. Smith celebrated its 100th anniversary. It also introduced its Conservationist line of residential water heaters.

One of A.O. Smith’s greatest expansions happened in 2001 when it acquired State Industries, Inc. This almost doubled the size of the A.O. Smith water heater business.

The company made another huge acquisition in 2007 when it bought GSW Inc. and the American Water Heater Company.

A.O. Smith would soon add the Whirlpool and John Wood brands to its name, cementing its place as one of the largest water heater companies in North America. In 2008, the company became one of the first U.S water heating companies to market units in India (3).

In 2010, A.O. Smith joined forces with Takagi Industrial Company. The companies agreed that A.O. Smith would acquire the North American operations of Takagi. They would work together to manufacture and market tankless water heaters in North America (4).

Today, A.O. Smith is focused on bringing its customers clean water through its many water treatment products. The company recently unveiled a new center in Milwaukee — the L.R Smith Corporate Technology Center.

Here, engineers use advanced research to develop portable and hydronic water heaters. They also carry out water treatment and air purification (5).

Where to Buy A.O. Smith Water Heaters

If you want to purchase an A.O. Smith unit, you can do so via its official website, hotwater.com. You can also find a wide range of 40-gallon tanks and other units on Amazon.

A.O. Smith Customer Service

You can contact A.O. Smith customer support directly via its website. Forms are available online to inform them of any issues. You can also find relevant email addresses and phone numbers, including international numbers for any customers outside of the U.S.

Customers can find manuals, catalogs, and spec sheets if required. The website also features a Product Selector Tool which helps consumers find the right unit for them. You simply answer a few questions and the tool will pick out a list of products and their prices (6).

In general, customers praise A.O. Smith for the great quality of its products. Although a few have received faulty units, customer service was quick to replace them.


Where Are A.O. Smith Water Heaters Made?

A.O. Smith’s current headquarters are in Ashland City, Tennessee, which is also the location of the company’s largest water heater factory. The company has five factories in the United States, as well as plants in China and the Netherlands, making it a truly global operation.

Are A.O. Smith Water Heater Glass Lined?

A.O. Smith innovated the glass-lined hot water tank more than 80 years ago and has continued to use them ever since. By using a layer of glass instead of holding the water in a steel container, A.O. Smith has effectively eliminated the risk of rust and corrosion in their water heaters. The glass also insulates better than steel, trapping heat inside and making the heaters more efficient.

Are A.O. Smith Water Heaters Self-cleaning?

A.O. Smith water heaters feature a self-cleaning dip tube that is designed to reduce the amount of sediment that can gather in the tank. This also reduces the minerals that can gather inside the heater, which is the leading cause of scale. This might not completely eliminate the need to flush your hot water heater but it should mean you can do it infrequently.

Is A.O. Smith a Good Brand of Water Heaters?

Many experts consider A.O. Smith the best brand of water heaters serving the US market. Although the corporation only has five manufacturing plants in the United States, its influence may be felt worldwide.

The manufacturing process of the company’s high-quality, eco-friendly, technologically innovative appliances continues to undergo development and improvement.

How Long Does an A.O. Smith Water Heater Last?

The lifespan of an A.O. Smith water heater is anywhere between 10 and 15 years. Regular maintenance performed by trained specialists can extend the life expectancy of your water heater to as much as 20 years

How Long is A.O. Smith Warranty?

Every A.O. Smith water heater is accompanied by a standard warranty that lasts between 6 and 12 years. This indicates that the makers of your water heater have high confidence that it will last for at least ten years and probably for twice as long even after the warranty has expired.

Are A.O. Smith Water Heaters Better than Rheem?

The two brands are comparable, and we can’t say which is better because it depends on your needs. Both Rheem and A.O. Smith are known for producing gas and electric water heaters of a high grade. The range of available units, pricing, and availability are two key differentiating factors.

Rheem heaters are more expensive but come with intelligent technology, solar choices, and wider availability. The prices of AO Smith models are comparable to those of other brands, and they provide a wider variety of gas water heaters.


A.O. Smith has a long history of leading the way with innovative technology and design. Their products, however, don’t appear to be very highly rated on major sites such as Amazon or HomeDepot.

Fortunately, their own website is easy to get advice or shop from. We still appreciate this company, largely because they have a water heater for almost every possible set of circumstances.

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About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.