5 Best A.O. Smith Water Heaters in 2021 – Reviews and Buyer’s Guide
By Anna A. MadsenLast Updated on 
Having to take a cold shower is perhaps everyone’s biggest fear, especially during the winter season. On top of that, chores like cleaning, doing dishes, and laundry turns the situation into a nightmare.
Hot water has become a modern-day staple of every household, be it small or large.
If you have been facing similar problems and have been looking around for a high-quality water heater, I’m sure you must have come across the name ‘A.O. Smith’ several times. It is simply not possible to talk about water heaters and not mention A.O. Smith, a company highly responsible for revolutionizing the water heater industry.
A.O Smith is undoubtedly one of the top brands in the water heater industry. With over 140 years of experience, the company has come up with hundreds of innovative ideas and tons of different water heating products.
The best features of the A.O. Smith water heaters are high performance and advanced technology with minimum energy consumption. Although these water heaters are relatively expensive, they make every penny worth the investment with their performance, efficiency, and durability.
In this article, we have reviewed five of the best A.O. Smith Water Heaters so that you can have some prior knowledge before you replace an old water heater with their products. Along with the detailed review, we have also included a comparison chart of each product and FAQs about the water heaters.
Let’s dive into it!
A.O. Smith ATI-540H-N
As one of the leading water heater companies, A.O. Smith produces several high-quality products, be it gas, electric, or even solar. Among all the different models, we rank A.O. Smith ATI-540H-N as the best A.O. Smith water heater available in the market.
Especially designed for residential purposes, the ATI-540H-N model is capable of delivering hot water at rate of 10 GPM. It is constructed with commercial-grade copper which is guaranteed to last for a long time. In addition to that, this unit qualifies the Energy Star requirements and is certified to ultra-low NOx regulations.
Quick Summary of Best A.O. Smith Water Heaters
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Top Pick for Excellent Performance
A.O. Smith ATI-540H-N Tankless Heater
A.O. Smith ATI-540H-N is simply a beast of a system when it comes to water heaters. With the capacity to deliver 10 gallons of hot water every minute, this unit is perfect for a medium household. Besides, it also exceeds the requirements of Energy Star and is recognized as an ultra low-NOx product. |
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Top Pick for Overall Performance
A.O. Smith BTR-200 Water Heater
Master-Fit BTR-200 is a gas-fueled tank-type heating system that delivers up to 8 gallons of hot water every minute, which is sufficient for a medium-sized family. Additionally, it is powered by self-cleaning technology that eliminates the sediment build-up inside the container. It also meets the efficiency standards of the United States Department of Energy with 80% thermal efficiency. |
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A.O. Smith Heating System with High Flow Rate
A.O. Smith ATI-510-N Tankless Heater
ATI-510-N is another gas fueled water heater on the list. This water heating unit is rigorously designed for both commercial and residential insulations. It can produce up to 10 gallons of water within a minute, which is more than enough for a medium family. Also, the primary heat exchanger of ATI-510-N is built out of heat-resistant HRS35 copper alloy. |
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Best Value for Money
A.O. Smith EJC-6 Water Heater
A.O. Smith EJC-6 is a compact water heating system that includes a single heating element. This electric residential heater also features a sturdily built brass drain valve. This space-saving water heater can virtually fit anywhere, be it under the sink or in crawl spaces. |
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Top Pick for Space-Saving Design
A.O. Smith GCR-40 ProMax Plus Water Heater
A.O. Smith GCR-40 ProMax Plus offers a highly economical performance by delivering up to 70 gallons of hot water every hour. The compact and space-saving design of this water heating unit not only provides high performance but also reduces energy consumption. Additionally, the water tank and spare parts of this A.O. Smith unit comes with a 6-year warranty. |
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Best A.O. Smith Water Heaters of 2021 - Reviewed
A.O. Smith ATI-540H-N Tankless Heater
Features Highlights
- High efficiency with a flow rate of 10 GPM
- Includes Air-Fuel Ratio (AFR) Sensor
- Ultra low-NOx emissions
- Sturdily built with commercial grade copper
- Offers both indoor as well as outdoor options
Product Specification
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Dimensions:
12.5 x 18.5 x 29.5 inches
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Weight:
59 pounds
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Flow Rate:
10 Gallons Per Minute
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Voltage:
120 Volts
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Material:
Commercial Grade Copper
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Warranty:
15 Years Limited Heat Exchanger Warranty and 5 Years Limited Parts Warranty
Well-suited for residential use, the A.O. Smith ATI-540H-N is made out of commercial-grade copper for heat exchanger. With a flow rate of 10 GPM, you no longer have to worry about running out of hot water at your home. This unit is ideal for a medium household that has three showers. Additionally, this model meets the energy efficiency requirements of Energy Star and is certified to ultra-low NOx regulations.
High-Efficiency Condensing Technology
A.O. Smith ATI-540H-N is equipped with the latest condensing technology that provides higher Uniform Energy Factors (UEF) and minimizes the fuel costs. This unit can deliver high-efficiency standards for a water heater with a flow rate of 10 GPM, which is enough for a medium to large family.
Ultra Low-NOx Emissions
This model by A.O Smith is rigorously designed to meet the stringent standards of Low-NOx emissions. In addition, this unit also coincides with South Coast AQMD Rules and Regulations for air quality management districts.
Heavy Duty Heat Exchanger
The primary heat exchanger of A.O. Smith ATI-540H-N is constructed using commercial-grade copper. This high-quality product is designed to be highly resilient against corrosion and offers relatively better heat transfer compared to stainless steel.
Multiple Safety
Features The ATI-540H-N comes with an extensive list of safety features. This product is equipped with built-in freeze protection that automatically triggers when the internal temperature of the tank falls below freezing. It also features a thermal cutoff fuse to prevent overheating and a built-in flame sensor to reduce the risks associated with combustion. Additionally, this water heating system also includes inlet and outlet thermistors that effectively monitors the water temperature.
Space-Saving Design
Unlike A.O. Smith’s conventional counterparts, the ATI-540H-N has a sleek and space-saving design that can virtually fit anywhere. The advanced wall-mount design makes this water heater ideal for homes with small space. In addition to that, this product is available in both indoor as well as outdoor models to help you choose what suits you the best.
Pros
- High flow rate up to 10 GPM
- Qualifies for Low-NOx standards
- Made out of commercial-grade copper
- Comes with multiple safety features
- 15 years warranty period
Cons
- Does not include remote control
- Smaller top clearance may limit the installation options
Our Verdict
A.O. Smith ATI-540H-N is one of the best options if you’re opting for a water heater for residential purposes. This high-quality heating system can deliver 10 gallons of hot water within a minute. This means it is capable of serving non-stop hot water for a medium to large household with up to three showers. With tons of safety features, this unit is also perfect for families with children. The ATI-540H-N by A.O. Smith is sturdily built out of commercial-grade copper and is backed by a 15 years warranty to ensure reliability and longevity of the product.
A.O. Smith BTR-200 Water Heater
Features Highlights
- Self-cleaning feature to stay protected against the buildup of lime and other sediments
- Longer-lasting CoreGard anode rods with anti-corrosive stainless steel core
- Features three sets of water connections
- Includes a low NOx burner
- Thermostat dual controller to reduce thermal stacking
- Meets the thermal efficiency of the U.S. Department of Energy
Product Specification
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Dimensions:
30.2 x 30.2 x 72 inches
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Weight:
630 pounds
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Flow Rate:
8 Gallons Per Minute
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Voltage:
120 Volts
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Material:
Stainless Steel
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Warranty:
Limited 3 Years Warranty
Master-Fit BTR-200 by A.O. Smith is a gas-fueled commercial heating system that delivers outstanding performance. This tank-type appliance offers a flow rate of up to 8 gallons per minute, which is enough for a medium-sized family.
This model is equipped with self-cleaning technology that reduces sediment build-up inside the tank. With 80% thermal efficiency, this water qualifies for efficiency standards of the U. S. Department of Energy.
Eliminator Self-Cleaning System
A.O. Smith BTR-200 is equipped with the Eliminator self-cleaning technology that is designed to get rid of sediment build-up in the water tank. This advanced feature helps to maintain the thermal efficiency and reduce utility bills of your home. In addition, the reduced sediment build-up in the tank also maximizes the tank life significantly.
Three Connection Options for Flexibility
For your convenience, this water heating system has included three different connection options. You can make the hot and cold water connections from the top, front, or rear of the system. However, the Eliminator system operates only when the cold water is connected through the front.
High-Quality Materials
This water heater is made out of stainless steel core along with CoreGard anode rods. The entire tank of this unit is fused with premium coating technology — PermaGlas Ultra Coat Glass Lining. These high-quality materials provide additional protection against corrosion and ensure the durability of the product.
Intermittent Electronic Ignition
This model is also equipped with an electronic ignition system that automatically operates the unit during the heating cycle to keep the water warm. Once the water reaches the right temperature, the burner and pilot turns off automatically. This advanced feature eliminates standing pilots and also reduces energy consumption. In case of flame failure, this system responds in less than a second and reduces the chances of gas leakage.
Codes and Standards
Master-Fit BTR-200 is one of the most efficient water heating systems manufactured by A.O Smith. This model exceeds the standby loss requirements and thermal efficiency of the U.S. Department of Energy and the ASHRAE/IESNA 90.1. It is also certified by the UL (Underwriters Laboratories) Sanitation and NSF Standard 5 for electrical safety, design, and structural integrity.
Pros
- Self-cleaning technology
- Highly durable CoreGard anode rods
- Anti-corrosive stainless steel core
- Features low NOx burner
- Thermostat dual controller
- Meets the standards of UL Sanitation and NSF Standard 5
Cons
- Less warranty period
- Expensive
- Bulky in size
Our Verdict
A.O. Smith BTR-200 is a premium tank-type water heater, specially designed for commercial purposes. Although it is relatively expensive, the performance and built-quality of this unit make every penny worth the investment. One feature that makes this water heater stand out among the crowd is its self-cleaning eliminator technology. This prevents sediment build-up in the tank and increases the lifespan of the system.
A.O. Smith ATI-510-N Tankless Heater
Features Highlights
- Has a maximum flow rate of 10 GPM
- Is available in both propane and natural gas variants
- Low NOx Emissions
- Qualifies with lead-free standards
- Compact size makes it convenient to mount the unit to your wall
- Built with heat-resistant HRS35 Copper Alloy
Product Specification
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Dimensions:
9.5 x 13.8 x 20.2 inches
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Weight:
39 pounds
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Flow Rate:
10 Gallons Per Minute
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Voltage:
120 Volts
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Material:
HRS35 Copper Alloy
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Warranty:
12 Years on Heat Exchanger and 5 Years on Parts
A.O. Smith ATI-510-N is a gas-fueled water heater that is designed for both commercial and residential insulations. This fully modulating tankless unit is capable of delivering 10 gallons of water within a minute. The primary heat exchanger of this unit is made out of heat-resistant HRS35 copper alloy.
Dual Heat Exchanger
Unlike other models, the ATI-510-N features a dual heat exchanger that is designed to transfer heat efficiently. The primary heat exchanger of this unit is made out of HRS35 copper alloy, which is more durable and more erosion resilient. Likewise, the secondary heat exchanger is constructed using 316L stainless steel which provides additional protection against corrosion.
Multiple Safety Features
Similar to the ATI-540H-N, A.O., Smith ATI-510-N also offers an extensive list of safety features. If the temperature of the tank drops below the freezing point, the built-in freeze protection system of this unit automatically adjusts the temperature.
In addition, this unit also has a thermal cutoff fuse to counteract overheating and thermistors to monitor the water temperature. It also has a built-in flame sensor to minimize combustion and ensure safety.
Space-Saving Design
As a tankless water heating system, the ATI-510-N comes with a compact and space-saving design. Whether you choose to put it under the sink or mount on the wall, this unit can virtually fit anywhere. Therefore, this system is excellent for homes that have limited space for tank-type water heaters.
Low NOx Emission Standard
Similar to other ATI models, ATI-510-N also exceeds the requirements for low NOx emissions. With the ATI series, A.O. Smith has been doing their parts to meet the NOx emission standards and protect the environment. With this, the unit not only delivers high performance but also consumes less energy and reduces your utility bills.
Pros
- Consists of dual heat exchanger
- Delivers high flow rate of 10 GPM
- Low NOx Emission Standard
- Compact and space-saving design
- Constructed with heat-resistant copper alloy
- Backed by 12-year warranty
Cons
- Relatively expensive
Our Verdict
A.O. Smith ATI-510-N is simply a beast when it comes to the water heating systems. With a compact design and high performance, this unit is ideal for both residential as well as commercial applications. This appliance is constructed with high-quality copper alloy and has a high flow rate of 10 GPM. Additionally, the manufacturer also provides a 12 years warranty on the heat exchanger and a 5 years warranty on spare parts.
A.O. Smith EJC-6 Water Heater
Features Highlights
- Meets or exceeds with HUD standards
- Compact and space-saving design
- 6-years limited warranty on tank and spare parts
- Features eco-friendly insulation to prevent heat loss
- Includes tamper-resistant brass drain valve
Product Specification
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Dimensions:
14.2 x 14.2 x 15.2 inches
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Weight:
25.6 pounds
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Flow Rate:
6 Gallons Per Minute
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Voltage:
120 Volts
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Material:
Commercial-Grade Copper
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Warranty:
Limited 6 Year Warranty on Tank and Parts
A.O. Smith EJC-6 is an electric residential heater that features a single heating element and a highly durable brass drain valve. This compact unit is designed to fit under the counter or in crawl spaces. This top-class water heater is equipped with an ASME Rated and CSA Certified T&P relief valve.
Blue Diamond Glass Coating
The entire body of A.O. Smith EJC-6 is coated with Blue Diamond glass coating. This premium coating acts as a superior shield against corrosion compared to standard glass lining. This provides additional protection to the unit and ensures the durability and longevity of the unit.
Enhanced-Flow Brass Drain Valve
This model uses a tamper-resistant brass drain valve that enhances the flow of hot water at your home. This easy-to-use valve features a ¼ turn radius screwdriver slot, which not only allows the water to flow straight-through but also offers a quick shut off as well. With a high-quality drain valve, this unit is capable of delivering an instant and continuous supply of hot water at your home.
Space-Saving Design
Perfect for small homes, apartments, and even RVs, A.O. Smith EJC-6 is a close-packed water heating product. With a single heating element, this model can fit almost anywhere, even in the tightest of spaces, to save valuable space. Therefore, if you do not have a large space at your home to add a bulky water heater, this model should be the best option.
Low NOx Emission Standard
Similar to other A.O. Smith products, the EJC-6 also exceeds the standards for low NOx emissions. This means, this model is not only efficient and high performing, but it is also a much cleaner and environment-friendly water heater in the market.
Warranty
A.O. Smith does not compromise when it comes to the quality of their products. The EJC-6 model is made out of commercial-grade copper, which is much higher in quality compared to standard copper material. Although sturdily built, this model comes with a 6-year limited warranty for the tank and spare parts to ensure the reliability and durability of the product.
Pros
- Highly efficient
- Space-saving and compact design
- Backed by a limited 6-year warranty
- Durable and long-lasting
- Ideal for small families, trailer homes, or RVs
- Does not require batteries to operate
Cons
- Single heating element
Our Verdict
A.O. Smith EJC-6 is an excellent residential heater for small households. Although it only has a single heating element, it does its job fairly well. In addition, it is backed by 6 years warranty on water tanks and spare parts.
A.O. Smith GCR-40 ProMax Plus Water Heater
Features Highlights
- Blue Diamond glass coating to block scale formation
- Equipped with internal microprocessor
- Meets the standards of National Appliance Energy Conservation Act (NAECA)
- DynaClean diffuser dip tube maximizes output and reduces sediment buildup
- LED status indicator to monitor the operation
Product Specification
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Dimensions:
22 x 22 x 58.5 inches
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Weight:
165 pounds
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Flow Rate:
6 Gallons Per Minute
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Voltage:
120 Volts
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Material:
Stainless Steel
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Warranty:
Limited 6 Year Warranty on Tank and Parts
A.O. Smith GCR-40 ProMax Plus is designed to deliver the most economical performance with a first-hour rating of 70 gallons at 41 GPH recovery rate. Although this unit is not Energy Star qualified with 0.62 Energy Factor, it meets the requirement of Low NOx emission. This means the water heating system can certainly reduce energy consumption and lower your energy bills. In addition, it comes with a 6-year limited warranty on tank and spare parts.
Intelligent Control Logic
This model is equipped with an internal microprocessor that provides much better operating parameters and fast heating response for optimized performance. Unlike conventional water heaters, this system uses thermophiles to produce the energy required to operate the gas control. It also features an LED status indicator that helps to monitor the system operation and service diagnostics.
Green Choice Gas Burner
The gas burner of GCR-40 ProMax Plus features an eco-friendly design. This model is rigorously engineered to reduce NOx emissions by up to 33 percent. Therefore, this water heating system meets the requirements of Low-NOx emissions of less than 40 ng/J.
DynaClean Diffuser Dip Tube
One exceptional feature of GCR-40 ProMax Plus is its advanced DynaClean diffuser dip tube. Constructed with highly durable PEX cross-linked polymer, this tube reduces sediment and lime buildup in the tank and maximizes hot water output.
CoreGard Anode Rod
This model also features high-quality anode rods with a stainless steel core. This helps to extend the life of the core wire and allows superior protection to the tank, longer than standard anode rods.
Pros
- Blue Diamond glass coating
- Advanced DynaClean Diffuser Dip Tube
- Low NOx Emission
- Has an internal microprocessor
- LED status indicator
Cons
- Not Energy Star rated
- Bulky in size
Our Verdict
A.O. Smith GCR-40 ProMax Plus is designed to deliver the most economical performance with a first-hour rating of 70 gallons at 41 GPH recovery rate. Although this unit is not Energy Star qualified with 0.62 Energy Factor, it meets the requirement of Low NOx emission. This means the water heating system can certainly reduce energy consumption and lower your energy bills. In addition to that, it comes with a 6-year limited warranty on tank and spare parts.
Comparison Table for A.O. Smith Water Heaters
| SN | Product Name | Dimensions (inches) | Weight (pounds) | Material | Flow Rate (GPM) | Voltage (Volts) | Warranty |
|---|---|---|---|---|---|---|---|
| 1 | A.O. Smith ATI-540H-N Tankless Heater | 12.5 x 18.5 x 29.5 | 59 | Commercial-Grade Copper | 10 | 120 | 15 Years Limited Heat Exchanger Warranty and 5 Years Limited Parts Warranty |
| 2 | A.O. Smith BTR-200 Water Heater | 30.2 x 30.2 x 72 | 630 | Stainless Steel | 8 | 120 | Limited 3 Years Warranty |
| 3 | A.O. Smith ATI-510-N Tankless Heater | 9.5 x 13.8 x 20.2 | 39 | HRS35 Copper Alloy | 10 | 120 | 12 Years on Heat Exchanger and 5 Years on Parts |
| 4 | A.O. Smith EJC-6 Water Heater | 14.2 x 14.2 x 15.2 | 25.6 | Commercial-Grade Copper | 6 | 120 | Limited 6 Year Warranty on Tank and Parts |
| 5 | A.O. Smith GCR-40 ProMax Plus Water Heater | 22 x 22 x 58.5 | 165 | Stainless Steel | 6 | 120 | Limited 6 Year Warranty on Tank and Parts |
FAQs on A.O. Smith Water Heaters
Although accidents are rare when it comes to water heaters, A.O Smith does not compromise even for rare incidents. The water heating systems by A.O. Smith is equipped with a thermal cutout technology that simultaneously cuts off the live and zero line. This means the system automatically cuts off the supply of electricity if the temperature of the water exceeds the highest pre-set limit.
In addition, they also feature a safety valve, which relieves and discharges water if the water temperature or water pressure overshoots the pre-set limits. In such cases, the safety valve discharges the water by opening up through the drainage.
When it comes to quality and performance, A.O. Smith is one of the best names in the market for water heaters. All the heating elements used in A.O. Smith water heaters are glass-coated. This premium glass coating helps to prevent scaling and extend the lifespan of the water heater.
Additionally, A.O. Smith also manufactures water heaters with dual heating elements. These units are much faster and highly efficient. Also, if one of the heating elements fail to operate, the other one works as a backup to ensure you get the hot water all the time.
The company provides a minimum of two years warranty for the heating element, which can also be extended if you register it in the first two months of purchase. This is one of the longest warranty periods you will get in the water heaters industry.
No, only a few selected water heating models include remote control on the set. For others, you have to buy the remote control separately. A.O. Smith offers a wide range of units that comes with corded as well as wireless remote and user-friendly settings.
The digital display comes in handy to set the water temperature, quick heating mode, real-time clock, and power options. In addition, it also indicates the actual water temperature inside the unit and the amount of electricity consumed by the system. These water heaters also come with a built-in LCD with user-friendly controls.
The inner container of water heaters manufactured by A.O.Smith is built with a heavy gauge mild steel and premium Blue Diamond technology. With sturdy construction and high-quality materials, these units are built to last for years. Besides, the water tank of A.O. Smith water heaters come with a 5 to 7 years warranty. Quick useful tips: If you're using your water heater for a long time and unknown about the age of your product, you can simply follow these guideline on how to determine the age of a water heater.
A.O. Smith Water Heaters are extremely stylish and well designed with glossy and sheeny outer cover. While the color options depend upon the country you come from, they do offer you a ColourMatch System. With this system, you can match the color of your water heater with the bathroom. A.O. Smith appliances mostly come in ivory or white outer with decorative front panels. Also, these outer can be easily changed in eight different colors.
Conclusion
Well, that’s all regarding the best A.O. Smith water heaters available in the market. I hope this article has helped you choose the right A.O Smith water heater for your home. All the water heaters mentioned on this list are engineered to deliver high performance and an endless supply of hot water. Cheers!
