Best AO Smith Gas Water Heater? (2021 Review)

Last Updated On October 19, 2021
best AO Smith gas water heater

The name AO Smith appears quite often in consumer searches for a new gas water heater. 

AO Smith makes some of the most popular products in the water heating industry, and many people sing the company’s praises while enjoying a hot shower. 

If you want to try an AO Smith gas water heater, you need to pick the product that suits your needs the best by comparing the most popular products on the market.

In this PlumbingNav guide, we will cover: 

  • Different types of AO Smith water heaters
  • How AO Smith water heaters work
  • What to look for in a new AO Smith gas water heater
  • Top 5 AO Smith gas water heaters reviewed

ImageProduct
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AO Smith 50 Gallon Vertex GDHE-50 Water Heater
  • Everlasting, quick hot water 
  • 96% efficiency 
  • Touchscreen control panel
  • Everlasting, quick hot water 
  • 96% efficiency 
  • Touchscreen control panel
View on Amazon
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AO Smith 40 Gallon ProMax GCR-40 Water Heater
  • Low NOx electronic push-button ignition
  • Blue Diamond glass coating in tank
  • Short design
  • Low NOx electronic push-button ignition
  • Blue Diamond glass coating in tank
  • Short design
View on Amazon
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AO Smith Commercialist BT-80 Tank Type Water Heater
  • High temperatures up to 180°
  • Insulated tank
  • Corrosion protection
  • High temperatures up to 180°
  • Insulated tank
  • Corrosion protection
View on Amazon
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AO Smith ATI-540H-N Condensing Tankless Water Heater
  • 12 year warranty 
  • .93 UEF
  • Flexible installation
  • 12 year warranty 
  • .93 UEF
  • Flexible installation
View on Amazon
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AO Smith ATO-310-P Non-Condensing Tankless Heater
  • Remote control included
  • 15-year warranty 
  • Convertible from propane to natural gas
  • Remote control included
  • 15-year warranty 
  • Convertible from propane to natural gas
View on Amazon

Our Overall #1 Rated Pick

Updated On May 21, 2021

AO Smith 50 Gallon Vertex GDHE-50 Water Heater

Never run out of hot water again with this hybrid 50 gallon water gas heater that produces hot water at 4 gallons per minute even after you empty the tank.

The condensing technology allows the device to run off of natural gas at 96% efficiency and earn a .88 UEF rating (as well as an Energy Star certification). This product also meets ultra-low NOx requirements. 

AO Smith offers a six-year limited warranty on this product. It also comes with a digital touchscreen display, spiral heat exchanger that encloses the heating element, and recirculating technology. 

Perfect for large families that take long showers and households that prefer to spend a little more upfront in exchange for utility savings and advanced comfort.

Our Top 5 AO Smith Gas Water Heaters?

Need hot water now? Here is a quick list of the top 5 AO Smith gas water heaters!

  1. AO Smith 50 Gallon Vertex GDHE-50 Water Heater (Our Top Pick)
  2. AO Smith 40 Gallon ProMax GCR-40 Water Heater(Best Budget)
  3. AO Smith Commercialist BT-80 Tank Type Water Heater  (Best High End)
  4. AO Smith ATI-540H-N Condensing Tankless Water Heater (Best Tankless)
  5. AO Smith ATO-310-P Non-Condensing Tankless Heater(Best Point of Use)

What's In This Guide?

      Overview Of AO Smith Gas Water Heaters

      Founded in 1895, the respected AO Smith brand has made water heaters for over 125 years and maintains the same passion for high-quality and accessible products to this day. 

      You can see the trust in the brand by simply looking at the numbers. 

      AO Smith generated 532.9 million in sales in North America during the first quarter of 2020 with no signs of slowing down. 

      All of these factors place AO Smith at the top of the list of reliable and recognizable water heater manufacturers with names like General Electric, Whirlpool, Bradford White, Rheem, and EcoSmart.

      All of the major brands create quality products with variations regarding materials, technology, selection, warranty, and user-friendliness.

      AO Smith carries a wide range of water heaters for all needs. Some of the various types of water heaters they make include:

      • electric water heater
      • heat pump water heater/hybrid water heater
      • gas tankless water heater
      • electric tankless water heater
      • commercial water heater
      • storage tank water heater

      In this article, we will focus on the gas water heaters available to eliminate the need to rely on electricity.

      What Are The Different Types Of AO Smith Gas Water Heaters?

      Storage Tank Water Heaters 

      Conventional storage tank water heaters use a tank to store hot water until you need it. 

      Once you use up the hot water in the tank, the water heater refills the tank and reheats the hot water so that you have it ready for the next time you need it. 

      Tankless Water Heaters 

      AO Smith tankless water heaters provide water on demand, making the units more efficient than storage tank units that must constantly run to keep the water warm. 

      You may experience an upfront cost to upgrade to a tankless water heater, but most people see a return in the lower utility bills after a couple of years. 

      Condensing Water Heaters 

      Natural gas and propane water heaters need to safely release the gases they emit when in use. Condensing water heaters absorb the heat from the gases and use the heat to help heat the water, increasing energy efficiency. The cold gas can escape through plastic, inexpensive PVC pipes.

      Less efficient non-condensing units require pipes made from more durable (and expensive) material since they must release hot gas that may damage PVC pipes. 

      Ultra Low NOx Emissions Water Heaters

      Ultra Low NOx emissions water heaters release exceptionally low amounts of toxic fumes into the air as they operate, keeping the air clean and reducing your home’s carbon footprint.

      did you know AO smith best gas water heater

      How Does An AO Smith Natural Gas Or Propane Water Heater Work?

      A gas water heater uses gas to generate heat as opposed to an electric water heater that runs on electricity.

      The gas can come from a public gas supply line or a private gas or propane tank.

      Cold water enters the hot water heater through the cold water inlet. 

      When the thermostat comes into contact with the thermostat, the thermostat activates the ignition. 

      Gas water heaters either have a pilot light ignition or electronic ignition. Most people prefer electronic ignitions for the increased safety and efficiency, but other people prefer the traditional pilot light ignition since it doesn’t require any electricity at all, meaning you can still get hot water during a power outage. 

      The ignition initiates the gas burner to heat the water until the thermostat senses it reaches the correct water temperature. The device sends hot water to the desired fixture through the hot outlet line, and it releases gases outside via pipes that lead the gas out horizontally (direct vent) or vertically (power vent).

      What Do You Look For In The Best AO Smith Gas Water Heaters? 

      Proper Size

      To pick the correct size water heater tank, you need to consider the following factors:

      • Hot water usage (especially during peak hours, such as the morning)
      • Standard or Energy Star appliances
      • Low flow or standard showerheads
      • Temperature rise

      If looking into a tankless model, pay close attention to how many fixtures may run at one time. 

      While storage tank water heaters can send water to as many devices as necessary until the tank becomes empty, tankless units deliver water based on water flow rate measured in gallons per minute (GPM). Water flow demands increase the more fixtures request water. 

      High Efficiency

      You want to buy a water heater that has high levels of both thermal efficiency and operational efficiency. They work together to reduce your utility bills every month, helping make up the cost for the new appliance. 

      Thermal efficiency refers to how well a product retains the heat inside of it so that it doesn’t constantly need to reheat the water in the tank. 

      Operational efficiency refers to how much gas and electricity the product uses. Experts measure efficiency in a measurement called the Unified Energy Factor (UEF). The higher the number, the more efficient the product. 

      See how AO Smith water heaters are made:

      Review Section Reviewed

      Now let’s explore our favorite units so you can decide on the perfect choice for your situation.

      Our #1 Rated Pick: AO Smith 50 Gallon Vertex GDHE-50 Water Heater

      AO Smith 50 Gallon Vertex GDHE-50 Water Heater

      Our #1 Top Pick

      Never run out of hot water again with this hybrid 50 gallon water gas heater that produces hot water at 4 gallons per minute even after you empty the tank.

      The condensing technology allows the device to run off of natural gas at 96% efficiency and earn a .88 UEF rating (as well as an Energy Star certification). This product also meets ultra-low NOx requirements. 

      AO Smith offers a six-year limited warranty on this product. It also comes with a digital touchscreen display, spiral heat exchanger that encloses the heating element, and recirculating technology. 

      Perfect for large families that take long showers and households that prefer to spend a little more upfront in exchange for utility savings and advanced comfort.

      Pros

      • Everlasting, quick hot water 
      • 96% efficiency 
      • Touchscreen control panel

      Cons

      • Creates condensation
      • Limited life expectancy
      • Bulky and heavy (almost 300 lbs. empty)

      Our #2 Rated Pick: AO Smith 40 Gallon ProMax GCR-40 Water Heater

      AO Smith 40 Gallon ProMax GCR-40 Water Heater

      Best Budget

      For all of the reliable features you expect and a design made for longevity as opposed to luxury, consider the ProMax series propane water heater at ⅓ the price of more expensive gas models. 

      The 40 gallon tank can support approximately 3 showers back to back, or 2 showers simultaneously, which accommodates the needs of the average household. If you do run out of water, it will only take about an hour to heat up the full tank again. 

      This product uses propane, which some people prefer to natural gas, and non-condensing technology to earn a .66 UEF energy efficiency rating, which doesn’t quite make it an Energy Star certified product. However, it does have a low-NOx electronic push-button ignition. 

      The tank contains Blue Diamond glass coating and a CoreGuard anode rod to prevent corrosion as well as a Dynaclean diffuser dip tube to prevent sediment buildup (not a substitution for regular maintenance) that give AO Smith the confidence to provide a six-year limited warranty. 

      Perfect for someone on a budget who likes practicality over flash. 

      Pros

      • Low NOx electronic push-button ignition
      • Blue Diamond glass coating in tank
      • Short design

      Cons

      • Limited standard vent options
      • Low energy efficiency rating of .66 UEF
      • Only suitable up to 150 psi

      Our #3 Rated Pick: AO Smith Commercialist BT-80 Tank Type Water Heater

      AO Smith Commercialist BT-80 Tank Type Water Heater

      Best High End

      If you need power, high temperature (up to 180°), and a large tank, this 80 gallon natural gas commercial water heater from the AO Smith Commercialist line can provide 80 gallons of water at operation levels that meet national efficiency and low emissions requirements. 

      The tank has insulation to prevent the heat from escaping, and it contains Blue Diamond glass coating and anodic protection to prevent corrosion. 

      Due to the high temperature capabilities, AO Smith gives this product a 3 year limited warranty. 

      Pros

      • High temperatures up to 180°
      • Insulated tank
      • Corrosion protection

      Cons

      • No digital display
      • 3 year warranty 
      • Not suitable for over 150 psi water pressure

      Our #4 Rated Pick: AO Smith ATI-540H-N Condensing Tankless Water Heater

      AO Smith ATI-540H-N Condensing Tankless Water Heater

      Best Tankless

      Get everything you could want from a modern unit at a great price with the 50 gal tankless natural gas water heater 540 series. 

      This unit generates up to 9 GPM of endless water, enough to comfortably support three showers at once. 

      The condensing technology allows the device to run at .93 UEF, and it comes with an ultra-low emissions electronic ignition. 

      You can also install the device in many locations thanks to its small size, power vent design, and long vent length (70’ at 3 diameter and 100’ at 4 diameter). 

      The device comes with a 12-year warranty, and an air-fuel ratio (AFR) sensor.

      Perfect for someone who wants to cut down on utility costs and save space without spending too much money.

      Pros

      • 12 year warranty 
      • .93 UEF
      • Flexible installation

      Cons

      • High installation costs (if upgrading)
      • No propane/natural gas conversion kit
      • Indoor only 

      Our #5 Rated Pick: AO Smith ATO-310-P Non-Condensing Tankless Heater

      AO Smith ATO-310-P Non-Condensing Tankless Heater

      Best Outdoor / Point of Use

      If you want to install your water heater outside to avoid having gases inside of your home, the outdoor 310 series propane tankless water heater was made to withstand the elements thanks to the stainless steel casing and freeze protection. 

      While the device isn’t as efficient as condensing units, it runs at a respectable .81 UEF.  It also has a maximum water flow of 8 GPM, enough to support 2.5 baths in cold weather. 

      AO Smith offers a 15-year warranty on the heat exchanger. 

      Perfect for outdoor installation for a cabin or a whole-home solution for a small home. 

      Pros

      • Remote control included
      • 15-year warranty 
      • Convertible from propane to natural gas

      Cons

      • .81 UEF 
      • May not provide enough water for whole home solution
      • Professional installation may be required

      FAQs About AO Smith Gas Water Heaters

      Which brand of gas water heater is best?

      AO Smith makes a great gas water heater. However, so do brands such as Rheem, Rinnai, American Standard, EcoSmart, and a number of others. 

      Is A.O. Smith a good brand for a water heater?

      AO Smith has experience, variety, technology, and high-end materials that allow them to give a great warranty on their products. You can rely on your AO Smith water heater to work properly. 

      How long do A.O. Smith gas water heaters last?

      Commercial products come with a 3-year warranty. 

      Residential storage tank products come with a 6-year or 10-year warranty. 

      Tankless water heaters come with a 15-year warranty. 

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