Rheem vs. AO Smith (Which One Is The Better Water Heater?)

Trying to decide between a Rheem or an AO Smith water heater for your home? Don’t worry, we know how tough the choice can be! Keep reading to find out a little bit about both brands and let us help you select the perfect one for you.

Rheem vs. AO Smith

In finding the best water heater company, both Rheem and AO Smith are easy contenders for the top. Both of them have a couple of hundred years of experience under their belts. They have also produced an impressive line of products. But when comparing the two, which of these water heater companies is the best?

Both AO Smith and Rheem are great names in the water heater industry. Rheem has a better overall product offering with a higher reach in the industry. But AO Smith is known to have a better customer experience. Regardless of what type of water heater you choose, both options will provide you with excellent longevity.

In this review, we will be looking over the details behind each company. We will be breaking them down into different best of categories based on product as well.

Don't want to do it yourself?
Get free, zero-commitment quotes from pro contractors near you.


A Review of Rheem

Rheem has been around since 1925. Over the past 100 years, they established themselves as one of the largest water heater companies in North America. They also have locations in Australia, New Zealand, and Mexico.

While they cover a wide variety of cooling and heating needs, their company is creates everything from tankless to standard tank water heaters. They also support gas, electric, and solar water heaters.

You can even have them apply to your commercial applications. Because of their long-standing commitment to excellence, you will regularly find them on “best of” lists. Their Professional and Prestige lines comprise a wide variety of highly-rated heaters.

Some of their heaters are known for being a bit high in the noise-level department. Some have concerns about them being made outside of the United States. Whatever the case may be, Rheem has a history of high-quality products.

Best-Selling & Rated Rheem Water Heaters

SaleBestseller No. 1
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
  • External digital thermostatic control with LED display (+/1 degree accuracy)
Bestseller No. 2
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
  • ON/OFF Dial Control with adjustable digital temperature display
Bestseller No. 3
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
  • External adjustable digital thermostatic control with LED display (+/1 degree accuracy

A Review Of AO Smith

AO Smith is another company that has been around for quite some time. It has produced its first water heater in 1939. They are known to be a company of innovation, as they made a glass-lined tank in the 1950s.

They have also joined the solar water heater market as of 2010, which brings them to be at the same high level of technology as others. They also offer the standard gas, electric, and tankless water heaters. If you work in the commercial area, you can also purchase their commercial heaters and boilers.

They have manufacturing locations in China, Europe, India, and the US. Some will express concerns with the international focus, but others feel it can improve their product.

One of their most robust lines includes the Proline, where they have produced the XE, which boasts enough energy efficiency for continuous heat during an unlimited shower.

Best-Selling A.O. Smith Water Heaters

Bestseller No. 1
A.O. Smith GPVL-50 ProMax Power Vent Gas Water Heater, 50 gal
  • Features an exclusive 3-position rotatable blower outlet which adds flexibility
SaleBestseller No. 2
A.O. SMITH 9003542005 Water Heater FV Pilot, 190-Degree C, Natural
  • 9003542 natural gas pilot assembly, works on the following water heater

Who Offers The Best Gas Heater?

We are comparing two different water heaters. First, we will be looking at the ProLine XE 50-Gallon Gas Water Heater by AO Smith and the Professional Classic Plus 48 Gallon Natural Gas Water Heater by Rheem.

Our findings have indicated that AO Smith’s ProLine provides better customer experiences.

Below, we will run a comparison telling you why we feel that AO Smith wins this section.

ProLine XE 50-Gallon Gas Water Heater Professional Classic Plus 48-Gallon Water Heater
50-gallon tank 48-gallon tank
6-year warranty 6-year warranty
.72 Uniform Energy Factor (UEF) .80 UEF
Energy star qualified Energy star qualified
51x24x24” (HxWxD) 60x22x22”

The Unified Energy Factor (UEF) is the Department of Energy’s method of communicating the energy efficiency of a water heater. The higher the number, the higher the energy efficiency.

The UEF varies a bit by size between your different options. Given that these are both the same size, the UEF is the right measurement of what to expect. The UEF on the Professional Classic Plus is a bit higher.

These water heaters are both Energy Star certified, which can potentially lead you to tax breaks in the right state. Not sure which water heater size you need? Check out our guide about Short vs. Tall Water Heaters!

The Proline also boasts of being able to handle more back-to-back showers. Customer experience also seems to match this based on online reviews from around the web.

It is because of that customer experience that we selected AO smith, as these two are pretty handy water heaters in any case.

Who Offers The Best Electric Heater?

This section will have us compare the Professional 50-Gallon Electric Water Heater by Rheem and the Vortex Hybrid Electric Heat Pump by AO Smith. Our choice goes to the Professional Classic Plus by Rheem.

Below is the quick side-by-side.

Voltex Hybrid Electric Heat Pump 50-Gallon Water Heater Professional Classic Plus 50-Gallon Electric Water Heater
50-gallon tank 50-gallon tank
6-year warranty 8-year warranty
3.42 UEF .93 UEF
Energy Star qualified Not Energy Star qualified
63x22x22” (HxWxD) 62x20x20”

The UEF on the Voltex is much higher. As a result, the Professional Classic Plus is not Energy Star certified based on its online claims. Being a different type of heater, they are subject to other requirements.

The Professional Classic Plus also has a bit more confidence in its product. There is an eight-year limited warranty instead of the Voltex’s six. The overall customer experience between the two is balanced. Still, the edge goes to the Professional Classic Plus Electric Water Heater. Longevity is incredibly vital in water heaters.

Who Offers The Best Electric Tankless Water Heater?

We have chosen the Electric Tankless 24kW by AO Smith and the 24kw Tankless Electric Water Heater by Rheem. Our choice goes to Rheem by a very slight margin.

Here’s the quick side-by-side:

Electric Tankless 24kW 4-Chamber Water Heater R4LA-240E 24kw Tankless Electric Water Heater
24kW 24kW
5-year warranty 5-year warranty
Unlimited shower minutes Unlimited shower minutes
5 GPM Up to 6 GPM (gallons per minute)
18x17x6” (HxWxD) 18x15x4”

Tankless water heaters are better at single appliances that use continuous water. As a result, they don’t typically work for more than one device at a time, but they do work continuously.

Both of these work similarly. The edge goes to the  Tankless Electric Water Heater by Rheem due to a higher GPM. That means it can handle more appliances. On all other fronts, they are incredibly energy efficient and can handle unlimited showers provided you don’t have them connected to one at a time. Find out here if an electric water heater can sit on the floor.

Who Offers The Best Condensing Gas Tankless Water Heater?

As you start looking at gas tankless water heaters, you begin to see some of these numbers crank up. That is because these are for three-bathroom or larger households.

Both the NOx Tankless Water Heater by Rheem and the High-Efficiency Pump by Rheem are great options. But the 15-year warranty is a significant difference-maker here, giving you five additional years of confidence.

Check out the side-by-side comparison below:

Tankless Water Heater Condensing Ultra-Low NOx High Efficiency 10.0 GPM Indoor Natural Gas Tankless Water Heater with Recirculation Pump
Energy Star certified Energy Star certified
15-year warranty 10-year warranty
.93 UEF .94 UEF
Unlimited back-to-back showers Unlimited back-to-back showers
24x18x11” (HxWxD) 29x17x15”

Both of these are incredibly close when it comes to their specifications. Also, they are both accredited by Energy Star. Their impressive UEF ratings indicate this. The real difference-maker here comes back to that 15-year warranty, but both are incredible options for your household.

Why Is Rheem A Great Choice For You?

Rheem has a fantastic selection of products that cover a wide variety of commercial and residential needs. Because of this, we have selected them to be the best brand by a slight edge.

In man cases, this edge comes from their focus in providing a useful product. They focus on what water heaters need to be helpful: efficient and simple water heaters. Rheem also tends to have a more substantial customer backing. Our findings revealed that the two are pretty close to positive responses, but Rheem covers many people.

That customer-base is a strong indicator of consistent quality. But don’t count out AO Smith as a distant second place. They are pretty close to Rheem in many ways.

Don't want to do it yourself?
Get free, zero-commitment quotes from pro contractors near you.


Why Is AO Smith A Great Choice For You?

In all of our research, we found that AO Smith won the war at energy efficiency. They are known for producing water heaters that can quickly provide a product that does not take up a sizeable electric footprint. As a result, many people pick AO Smith for a combination of good customer service and energy-efficient products.

Also, their site is far easier to understand on a consumer level. On AO Smith’s website, they simplify matters by making you think of water heaters regarding the number of showers and baths.

In many cases, simplicity is essential when it comes to getting a strong customer base. It is up to the company to educate the consumer on these matters. Rheem is good at this, but AO Smith looks to be slightly better.

While it may change in a few months, it is clear that Rheem does have an edge on their product line. Regardless, any of these options would be an excellent inclusion for your bathroom. As always, pick the water heater that works best for you, so don’t be afraid to shop around.

More Guides To Help You Pick The Best Water Heater For You

Eli Smith

I'm a guy who becomes the expert of whatever I stumble upon, writing-wise. I've written tons about cool home products, home improvement, and smart technology in the home. I'm also the proud father of a kiddo born on new years, making my holidays very busy.

Recently Published