Top 10 AO Smith Hot Water Heater 2019

Imagine, it is the dead of winter, freezing cold outside. Then you definitely seek comfort in the piping hot confines of your morning shower. The AO Smith Water heater gives you the best shower in cold winters. With the lights dimmed, the water touches your face and rolls over your shoulders. Your muscles relax one by one as the warmness of the water finds its way down your chilly, restless feet. Lathered with soap and shampoo, you slump against the warming tile, eyes closed. You consider falling back asleep standing fully upright when it happens. Your water heater has just bought the farm.

Best AO Smith Water Heater Reviews 2019

AO Smith, you may hear about this brand as it is popular in producing the best AO Smith water heaters. It stood as one of the worlds leading manufacturer of Commercial and Residential Water Heater equipment. You can also get the boilers, water purification system from this AO Smith brand. You can use these water purification products for residential and also for a light commercial purpose. Keeping aside the AO Smith story, let us now go into the AO Smith Water Heater reviews. As you know it is a top brand, there will be many water heaters available under this AO Smith brand. Each one is designed, developed and provided with separate features, specifications, and requirements. Not all users have the same requirement. So, there are many AO Smith Water Heaters available for different consumers. Among all, we have picked the best and listed those top 10 AO Smith Water Heater reviews below.


AO Smith Vertex GPHE-50 Water Heater

The AO Smith GPHE-50 is an Energy Star-certified gas water heater designed for a household of about four people. This AO Smith hot water heater has a thermal efficiency of 90 percent, that can mean more money in your pocket and can generate a constant flow of water at 3 gallons per minute. With its 76,000-Btu gas burner, the AO Smith Vertex GPHE-50 delivers a continuous and constant hot water flow to your home, rather than the sporadic flow of some gas water heaters. The AO Smith 50-gallon gas water heater is designed to take up minimal floor space. Hence, it is taller than a lot of competitors, standing about 68 inches below the draft hood. However, the GPHE-50 is only 27 inches in diameter. Hence you can put it in any corner and still have more storage space.

AO Smith GPHE-50

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AO Smith GPHE-50 gets the water hot when the pilot light is on for the gas-fueled burner at the bottom of the tank. However, this AO Smith water heater uses a spiral heat exchanger to retain heated combustion gases within the tank for long periods. This exchanger is strategically placed in the middle of your tank to better distribute heat and operate at 96 percent thermal efficiency. moreover, this is significantly higher than the standard heaters that operate at 80 percent. The Intelli-Vent Gas Control option of this gas water heater makes it easy for you to manage your water temperature and to adjust the system diagnostics. The AO Smith water heater includes a Green Choice gas burner and a brass drain valve. This 50-gallon gas water heater has a six-year limited tank and parts warranty.

  • More reliable.
  • Very efficient.
  • Cost saving.
  • Very compact.
  • Green choice gas burner.

  • Complex install.
  • Expensive.


AO Smith Vertex GAHH-50 Water Heater

The AO Smith Vertex GAHH-50 features the latest in atmospheric-vented water heating. Hence, becomes the best choice for those looking to replace out of date, inefficient water heaters. A patented pressurized combustion chamber and advanced air intake blower of this AO Smith water heater help deliver an optimal air-to-gas mixture. Hence, giving you top of the line water heating efficiency. This results in a .70 energy factor and more dollars in your pocket. The 50-gallon tank and 43 gallons per hour recovery rate of this best water heater means it can easily keep up with the hot water needs of an average household. The Effex line features an atmospheric vent system, that allows the AO Smith water heater to distribute an optimal air-to-gas mixture. This makes it one of the most efficient gas-powered water heaters on the market.

AO Smith GAHH-50

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This AO Smith heater is designed with optimized performance in mind, and hence the GAHH-40 uses intelligent control logic to control the flow of fuel into the geyser. That means better performance and a more efficient heating rate. A built-in easy to read controller on the GAHH-40 gives you easy access to temperature settings, operating mode, and multiple diagnostics to make sure your geyser is running exactly how you want it. The diffuser dip tube of this best geyser helps reduce lime and sediment buildup by redirecting incoming cold water to create turbulence. Hence, helps your water heater to run longer and better. These hot water heaters feature powered anode rods that are non-sacrificial, so they do not deplete over time. This also enables them to operate in all water conditions.

  • User-friendly electronic interface.
  • Electronic gas control.
  • Durable hot surface ignitor.
  • Easy installation.
  • Gives plenty of hot water.

  • Expensive.


AO Smith ATI-540H-N Hot water review

The ATI-540H-N tankless water heater uses up to 199,000 BTU/hr of natural gas. Hence, it delivers an endless supply of hot water for a 3 bath home in northern climates and up to a 4 bath home in southern climates. Utilizing condensing technology, this AO Smith Water heater is extremely efficient with a Uniform Energy Factor of 0.93. With an industry leading 15-year limited warranty, the AO Smith ATI-540H-N tankless water heater provides years of hot water through quality and innovation. The ATI-540H-N geyser features the latest in water heating condensing technology. This means that the hot water heater can deliver some of the highest efficiency standards on the market, keeping bucks in your pocket. The AO Smith ATI-540H-N heater is designed to qualify for the most stringent Low-NOx standards.

AO Smith ATI-540H-N

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However, these standards coincide with SCAQMD rules and other air quality management districts. The primary heat exchanger of this best water heater is built out of copper, offering better heat transfer than stainless steel and designed to be more flexible against corrosion. Moreover, A.O. Smith water heaters are built to last and save you money in the process. These ATI models come with a long list of safety features standard. These include built-in freeze protection, manual reset hi limit, inlet, and outlet thermistors to monitor temperatures, an overheat cutoff fuse and a built-in flame sensor. Furthermore, A.O. Smith tankless heaters take up less space than other conventional counterparts. The convenient wall mount design of this AO Smith electric water heater can fit in nearly any home layout and offer additional flexibility.

  • Space saving design.
  • More safety features.
  • Heavy duty heat exchanger.
  • Easy and simple to use.
  • High efficiency Condensing technology.
  • Easy installation.

  • A bit expensive.


AO Smith GDHE-50-NG

The AO Smith GDHE-50 Vertex 100 Power Direct Vent Gas Water Heater is a new type of hot water heater, that offers up to 96% efficiency and almost endless supplies of hot water. This is a gas condensing water heater, that starts out as a regular water heater with a burner under the tank. The A.O. Smith Vertex features a 50-gallon tank water heater with an output that exceeds regular gas atmospheric vent 75-gallon water heaters. Moreover, this AO Smith GDHE-50 has a 100,000 Btu burner, that in combination with the high efficiency can supply a seemingly endless supply of hot water at 4 gallons per minute. The AO Smith GDHE 50 NG can be vented with up to 120’ of PVC, ABS, or CPVC pipe and can also be concentric vented with an optional kit.

AO Smith GDHE-50-NG

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The Vertex is equipped with a condensate drain tee, factory installed T&P valve, and equipped with side mounted hot and cold recirculation tap. This permits hot water through recirculation loops. The AO Smith GDHE-50 hot water heater has an electronic control panel with an LCD display that gives diagnostics and temperature control. Plus, the interior of the tank, as well as the heat exchanger coil both inside and outside, are coated with a glass lining to give corrosion protection for the tank and heat exchanger in addition to the 2 anode rods. The burner on the A.O. Smith GDHE-50-NG can be fired on natural gas or, propane. This best ao smith vertex water heater is a green burner complies with the ultra-low NOx standards coming in 2012. The ao smith GDHE 50 ng comes with a 6-Year Limited Tank and Parts Warranty.

  • Power direct vent.
  • Advanced electronic controls.
  • Gives continuous hot water.
  • Easy installation.
  • Very efficient.

  • Highly Expensive.


AO Smith ENT-50 Water Heater

The AO Smith ENT-50 Pro Max water heater is an updated model base on a simple design. This AO Smith water heater has two standard 4500-watt electrodes, one up high, one down low that is pretty standard fare. Standing at around 60″ tall and 20 1/2″ in diameter, this hot water heater really is designed to replace a tall, skinny water heater in a closet or a small room in the house. Installing it in a crawlspace is, however, not suggestable. The AO Smith ENT-50 heater weighs in at 125 pounds, that is also pretty standard for this class of water heater. The anode rod that counteracts the electrolysis that would eat up your tank. Hence, this best AO Smith water heater uses a stainless steel core, for longer life and better performance. Most of the companies just use zinc or magnesium.

A.O. Smith ENT-50

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All hot water heaters have a coating inside. The Blue Diamond coating is an updated glass coating truly designed for longer life. The AO Smith ENT-50 water heater uses this Blue diamond coating to give the best results. The bottom electrode of this AO Smith Water heater is an upgraded Incoloy stainless steel electrode that better resists the dirt and debris in the bottom of the tank, compared to normal copper electrodes on most basic water heaters. This best water heater from AO Smith comes with DynaClean Diffuser Dip Tube. Here, the dip tube has a different tip on it than most. This helps to clean the tank at the bottom. Also, there is less sediment build-up accumulated from the hard water. At the bottom of the geyser, the A.O Smith have installed a brass drain valve instead of plastic that some companies use.

  • LED Status indicator.
  • Eco-friendly burner.
  • Durable brass drain valve.
  • Higher energy efficiency.
  • Superior corrosion protection.

  • Poor burner plate.


AO Smith XCG-50 Water Heater

The ProMax family from AO Smith water heater offers widespread benefits for families that are eligible for gas utility rebates. Outside of the AO Smith XCG50 is a superior glass lining that reduces the need for regular maintenance flushing. Moreover, you will be thrilled by the Dynaclean diffuser dip tube that comes with this AO Smith water heater. This helps houses that have a higher mineral content with their water. However, it reduces sediment build-up very well, especially when there are high lime levels, enabling a consistent hot water output when called upon. The control panel of this best geyser is used for adjusting your settings is in a standard configuration. However, it is small compared to some other water heaters, but still easy enough to use. There is also a warning light that will flash to let you know if something is wrong.

A.O. Smith XCG-50

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Plus, the A.O Smith manufacturer’s guide has a complete list of flash codes that help you diagnose an issue that may occur. Moreover, the AO Smith XCG-50 is a direct vent water heater. Connections are in a standard configuration. Hence, if you’ve had a gas water heater in the past, the installation is quick. The internal microprocessor of this XCG-50 offers superior functional parameters and precise detectors that provide a quick heating response for performance enhancement. Moreover, the intelligent control logic of this electric water heater uses a thermopile to generate enough power to run the electronic gas control system without any demands from external power sources. Additionally, the electronic gas control of this geyser features an LED status indicator to oversee all system functions and service analytics.

  • Blue diamond glass coating.
  • Self-powered electronic gas valve.
  • Faster heating response.
  • Good quality.
  • Nice design.

  • Cycling of hot water is a bit slow.


AO Smith GCR-40 Water Heater

The AO Smith GCR-40 is a capable performer as it does its work well and is pretty reliable. It works the way most tank-style gas or propane water heaters work. You can see a cold water inlet that goes to the bottom of the geyser through the Dyna Clean diffuser dip tube. It takes the cold water all the way to the bottom of the water heater closest to the burner. In the bottom of the heater, there is a burner assembly inside the propane heater under the tank, with a gas control valve mounted to the outside of the tank that controls the amount of gas used and how hot and how often the burners heat up water.  There is also a hot water outlet on top of its tank that goes to feed the water to your plumbing system.

AO Smith GCR-40

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As with all gas and propane water heaters, there has to be a vent on the top to let the vapor produced when burning fuel out of the heater and discharge outside the building safely. Some of these vents can be powered by a fan, or they can be double-walled to allow the exhaust gas and the intake of fresh air for combustion through the same piping system. Moreover, this AO Smith 40 gallon water heater has a standard exhaust flue. The only thing that is a bit more up to date on this water heater is its gas valve system. This gas valve, being computer controlled is much more accurate and has more settings than a standard old fashioned gas valve. This best water heater comes with an LED readout that can tell you what is wrong with the heater if it is not working right!

  • Works well.
  • Pretty reliable.
  • Does its job well.
  • Thermopile.

  • Delicate burner plate.


AO Smith EJC-6 Water Heater

With a 6-gallon tank and 1 element delivering 1650 watts, AO Smith EJC-6 is designed to fit into tight spaces. Its Coregard Anode helps shield the tank from the corrosive effects of water and comes with a 6-year limited warranty. Moreover, the Blue Diamond Glass Coating of this AO Smith water heater provides superior corrosion resistance. This AO Smith EJC-6 Residential Electric Water Heater is perfect for small homes, or even apartments in need of water heaters, who don’t have too much space available. The design of this best tankless water heater is incredibly compact (14”x14”x15”) means that it can even fit directly under a sink or in a large cupboard. Moreover, this AO Smith Electric Water Heater can also be placed in tight crawl spaces or even in small storage closets, as well.

AO Smith EJC-6

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These side-mounted additions are also immensely beneficial in trailer homes or RVs. Due to tight spacing in such homes, these side attachment options make it much easier to get everything connected and up and running. Furthermore, this AO Smith water heater EJC-6 does not require any batteries. This one relies on your existing electrical connections for power. Hence, there is no need to worry about making sure you have the right batteries all the time. This unit is hardwired with 120v. The unit can also be easily converted from hardwired to a plug connection with the right tools. This electric water heater is extremely efficient. Hence, almost no energy is wasted in the production of heating water. In fact, the smaller a water heater tank the greater the energy efficiency rating. This unit is extra small, hence gives fantastic energy efficiency.

  • Extremely efficient.
  • Very compact design.
  • Comes with a limited 6-year warranty.
  • Can last much longer.
  • Good for small families.

  • AO Smith EJ-6 only single heating element.


AO Smith EJCS-20 Water Heater

The AO Smith EJCS-20 electric water heater is designed to take up as little room as possible and is the ideal choice for when installation space is limited to tight spaces such as under counters and in crawl spaces. With a 19-gallon tank and 1 element delivering 2500 watts, the EJCS-20 AO Smith water heater is designed to fit into tight spaces. The Coregard Anode of this best electric water heater helps protect the tank from the corrosive effects of water and is accompanied by a 6-year limited warranty. moreover, this AO Smith hot water heater features a convenient flat porcelain surface at 36” height, providing extra “counter space” wherever it is installed. All plumbing and electrical connections of this 19-gallon water heater are made through the back side of the water heater.

EJCS-20 AO Smith

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However, this best water heater is equipped with a PEX cross-linked polymer dip tube. AO Smith EJCS-20 is one of the best COMPACT ELECTRIC WATER HEATERS. Hence, it comes with the Compact design, side-mounted plumbing and electrical connections (optional top-mounted water connections for field conversion). This best AO Smith water heater is mainly designed for installation under a counter, in a crawl space or in other tight spaces. The tank capacities of these range from 6 through 20-gallons and offer single heating element and durable tamper-resistant brass drain valve. Moreover, they are mainly designed for low-demand, point-of-use applications, such as buildings with remote restrooms. The Accessories of this AO Smith EJCS-20 includes a standard 110/120V cord set with 3-prong plug and wall-mounting bracket for easy installation.

  • Compact design.
  • Eco-friendly.
  • Durable Drain valve.
  • Industry-leading Anode technology.
  • Highly efficient.

  • Poor burner plate.


AO Smith BT-80 Water Heater

Helical internal heat exchanger provides much greater heat transfer surface than standard straight flue tube. The AO Smith BT-80 produces 90% thermal efficiency, that saves money on operating costs, increases hot water. Moreover, it also minimizes standby losses by trapping heat in the tank. The spiral heat exchanger of this best AO Smith water heater reduces scale and sediment from forming on the water-side surface. The BT-80 heater is equipped with 120 volts, 60 Hz electrical system, 6-foot cord with a standard 3-prong connector. 2in PVC pipe, elbows and condensate drain is also supplied to connect heat exchanger outlet to a blower. Moreover, this best water heater gives High output with a small footprint of 22in diameter. Side-mounted hot and cold recirculating taps allows this AO Smith BT-80 water heater to be installed as part of combination space heating/water heating applications. Else, any system requiring a recirculating hot water loop.

AO Smith BT-80

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The AO Smith BT-80 water heater also comes with plugs for the recirculating taps. This best hot water heater comes with INTELLI-VENT gas control. Hence, it is equipped with long-lasting silicon nitride hot surface ignitor. And however, there is no standing pilot. BT-80 from AO Smith water heater also has Advanced electronics for more precise control of water temperature and easy-to-understand system diagnostics. It is also provided with Permaglas Ultra Coat glass lining. Hence, A. O. Smith tankless water heater provides superior protection against corrosion. So, it can protect all interior tank surfaces including inside and outside of helical heat exchanger. This AO Smith electric water is equipped with two heavy-duty anode rods. Moreover, the Green choice gas burner patented design of this AO Smith water heater BT-80 reduces NOx emissions.

  • Heavy duty anode rods.
  • Green choice gas burner.
  • Easy maintenance.
  • Automatic shutoff.
  • Small diameters.

  • Expensive.

How to Choose the best Water Heater?

Having a water heater in your house is a long term investment. Hence, you should be able to choose the best water heater that works perfectly for your house. With the right choice of a hot water heater, you can be able to use for about 15 years, without any difficulty. However, it is important to note in most cases, 15 to 25 percent of the energy, in most homes goes to water heating.

It is, therefore, necessary to understand the various options of water heaters that are available on the market. This would help you make a good decision so that you can find a hot water heater that would serve your needs in an efficient manner. It is worth noting that there are some heaters, that tend to consume more energy than others.

Hence, we give some important considerations when buying a water heater.

Key Considerations

How much Sufficient Space You have?

As we all know, water heaters vary in height and diameter. If you are moving up in tank size, you need to make sure that you have enough space for the larger capacity. Also, some water heaters (usually heat-pump or hybrid types) need a certain amount of surrounding air. Hence, you need to plan for appropriate cubic square footage requirements. Water heaters that comply with current NACEA regulations may have more insulation than older heaters. Hence, these might be taller or wider than a heater they are replacing. However, check the specifications before buying if clearances are tight.

Energy Efficiency

Natural gas is more affordable in most areas of the country than electricity. And because as it is more efficient, gas water heaters cost less to run. Among all electric water heaters, those heaters that use heat pump capacity offer considerable energy savings. However, that is certainly enough to offset their higher cost in just a few years. Tankless water heaters are another energy efficient option. But they have some negative points that might not make them a perfect fit for every situation. Regardless of the type of fuel source, all new hot water heaters are subject to the current NACEA energy efficiency regulations, that went into effect in April 2015.

Do you have a natural-gas service in your home?

If you are choosing a gas water heater, you definitely need natural gas service to your home. If you don’t have it, consider the additional installation costs of running a gas line. However, this is a work that is best left to plumbing professionals for safety reason. Gas heaters that run on liquid propane are also available but may cost more to operate in the long run.

Consider your Electrical Needs

Residential water heaters require electricity to run. In case of a gas water heater, that is standard 115-volt service for the ignition system. However, some just plug into a convenient outlet. Electric heaters, including tankless electric heaters, need 240-volt service, and a dedicated line that is rated sufficiently to handle their current draw.

Consider your Venting

Gas water heaters have to be vented to the outside of your house. This can be handled in many ways. Be aware that even while replacing one gas water heater with another, local building codes might have changed from your last installation. The best recommendation is to consult a licensed plumber to be sure that venting is done safely and adequately.

Heat pump Water heaters

These are water heaters that capture heat from the air and then pass it on to the water. As a result, they will end up using about 60% less energy than other conventional water heaters. While the initial price appears to be more, you will recoup this within a very short period of time, through the energy costs that you save. However, it is important to note that these may not be effective in cold places. Moreover, they would only be effective in areas where the temperatures range from 40 to 90 degrees Fahrenheit. When installing the hybrid water heater, you need the clearance of about 7 feet from the floor to the ceiling. This is to be able to accommodate the heat pump, that is usually on top. You can choose this type of water heater as an extension to the storage water heater.

Ample Hot water Capacity

The right-sized water heater can provide your family with all the hot water it needs when costing less in terms of upfront price and energy consumption. As an example, a 50-gallon hot water heater can supply enough to meet the needs of a typical family of four. When sizing a tankless hot water heater, consider both your climate and your family’s needs.

Sufficient First Hour Rating

The first-hour rating is based on the hot water stored in the tank and the amount of incoming cold water that can be heated within an hour. The higher the rating, the more hot water you can receive during peak usage times in your house. However, online calculators can help you determine what FHR you need.

Low NOx

Natural gas fuels generate nitrogen oxide pollutants. Hot water heaters with a low NOx rating shoot less into the surrounding air. However, some areas of California needs ultra-low NOx water heaters. Hence, California residents need to check the regulations before selecting the best water heater. However, AO Smith water heater is one of the best choices that can be suggested to the people living in such areas.

High recovery rate

The recovery rate relates to how quickly the hot water heater can produce more hot water after the initial supply has decreased. A low recovery rate means you may be waiting a while or taking a cold shower once you use the initial power.

High Flow rate

The High flow rate refers to the number of gallons of hot water per minute (GPM) the hot water heater can produce. Clearly, higher flow rates are useful in many situations.


You are suggested to choose a water heater with at least a six-year warranty. Some warranties cover only the tank and parts, and most brands that cover labor limit it to just one year (though some high-end water heaters offer better labor coverage). The best water heaters like AO Smith Water Heaters, come with warranties of 10 to 12 or more periods.

AO Smith Hot Water Heater for Sale

A. O. Smith Corporation is one of the best leading manufacturers of residential and commercial water heaters and boilers, offering a comprehensive product line featuring the best-known brands in India, North America, and China. The company was founded in 1874 and is headquartered in Milwaukee, Wisconsin. A. O. Smith hires approximately 16,100 men and women at operations in India, Mexico, United States, Canada, United Kingdom, the Netherlands, Turkey, and China. Moreover, they also have sales and distribution in more than 60 countries around the world. As a global leader, the company’s main goal is to be a leading global water technology company worldwide.


AO Smith is one of the oldest and largest water heater manufacturers. That is the reason nowadays, why most of the offices and outlets of reputed organizations like McDonald’s, Procter & Gamble, Goldman Sachs, Pizza Hut etc use water heating solutions from AO Smith. Another major plus point is that AO Smith has been the pioneer in water heater innovations. Patented Blue Diamond Glass Coating and concept Air2Heat heaters are the best examples of that. But if you are the one who is looking for a quality electrical water heater, AO Smith water heater should be your definitive choice.

Hope you all enjoyed this best AO Smith water heater reviews. Stay in touch with us to get updated water heater reviews. Thank you!! Stay cool with this Hot Water Heater.

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