AO Smith Water Heaters
Review & Buying Tips

The AO Smith water heaters review helps you find the best models to buy from one of the biggest US manufacturers of HVAC equipment. Search, review and select a model from the ProLine, Voltex, Polaris, Voltex, and Vertex series, powered by electricity, natural or propane gas, and built with the water tank or tankless technology.

The list of AO Smith hot water heaters for residential applications is very long, so homeowners have more flexibility and options to choose from, from the economy gas and electric models to the advanced models with superior features and quality, some equally good as found in the commercial line.

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This is what you will find in our review on AO Smith water heaters:

  1. Top features
  2. Gas models
  3. Electric models
  4. Hybrid
  5. About AO Smith manufacturer

Advanced features

The AO Smith manufacturer, as a leader in innovation and manufacturing energy-saving models, designs, builds, distributes, and field supports an entire line of residential and commercial water heaters and boilers, offering many great features, such as:

  • Blue Diamond - commercial-grade glass coating that provides superior corrosion protection and longer tank life, due to the high-quality material and advanced technology.
  • CoreGard anode rod - made of stainless steel that protects the internal metal tank surface from corrosion. Standard models utilize one, while better models have two rods, or powered anodes, resulting in better protection and longer warranties.
  • DynaClean is the automatic sediment cleaning system that utilizes durable dip tubes, so less sediment build-up accumulated from the hard water.
  • Self-powered electronic gas valve - uses a microprocessor, thermopile, and LED status indicator, so water heater works with enhanced performance, independent of the external power source, easily controlled and troubleshoot.
  • Green Choice is an eco-friendly burner designed to reduce greenhouse gases by up to 33%.
  • AO Smith water heaters meet a standard, "Flammable Vapor Ignition Resistant," that deals with the accidental ignition of flammable vapor outside of the water heater. For the ignition problems on AO Smith Vertex models and how to troubleshoot, check out this step-by-step guide.
  • Durable brass drain valve, heat trap nipples, and hot-surface ignitor for higher energy efficiency and reduced energy consumption.

AO Smith water heaters review

There are two main types of AO Smith water heaters for home use; tank-type with the capacities of up to 98 gallons and tankless for single or multiple fixtures use, both powered either by gas or electricity. According to the manufacturer, all the models are grouped into three categories where the ProLine XE is the best to buy.

Best gas models to buy

Tank type

Residential gas water heaters from AO Smith come in a much greater number than the electric type, where various models are available. Based on the venting options, gas models are found as the atmospheric, power vent, direct vent, and power direct vent.

Gas models are coming from the ProLine series and are recommended to every homeowner, either looking for the economy models, models with the reduced gas emission, condensing with the ultra-high efficiency, or high recovery - for larger families.

AO Smith water heaters are also designed with the latest technology, state-of-the-art design, and long-lasting elements. 

Vertex and Polaris, with the helical heat exchanger, condensing design, advanced gas and electronic control, heavy-duty anodes, and stainless steel tank, are two of the most innovative and efficient tank-type models from AO Smith.

When it comes to savings, a Vertex Power-Direct Vent model is the high-performing and Energy Star unit that also provides an endless supply of hot water and has an annual cost of operation of around $200 (2017).

More affordable that is coming from the best ProLine XE series is the power-direct vent model GPDX 50L. This 50-gal model has the highest first-hour rating (118 gallons) and energy factor (0.73) of all non-condensing models with the 50-gal tank capacity. Or, if you need a water heater that produces more hot water, buy s GPDX 75L model.

Tankless series

AO Smith water heaters are also designed with tankless technology, which means water is heated on demand and distributed in endless supply, either for point-of-use or whole-house use.

The ProLine XE tankless series are available as the condensing and non-condensing, where the high efficient models, with the recirculation pump and low gas emission, are the most advanced. AO Smith tankless heaters are smart, safe, and small and can be installed either inside or outside (depends on the model).

A good example is the model ATO-540H-N, one of the top sellers and with the most positive user reviews. It comes with commercial-grade components, high energy factor, and water flow, making it ideal for homes with up to 4 baths.

This is a good buy.

Residential electric models

Most of the AO Smith water heaters that use electricity come from the ProLine series, built for residential and mobile homes, as the standard or advanced models. One of the top water heaters is coming from the ProLine XE series, featuring the electronic display, diagnostic system, stainless steel heating elements, dry fire protection, multiple operating modes and

10-year warranty.

This is what ensures maximum energy savings, excellent power output, faster recovery, and reliable operation.

Electric models are designed for special use also, as the Lowboy, Table Top, or point-of-use for under-sink installations and single-use.

Hybrid models

With the addition of the heat pumps, AO Smith electric water heaters can now operate with ultra-high efficiency, two times more efficient than the conventional type.

This is what makes Voltex heat pumps Energy Star compliant that can save over 50%. These are also known as hybrids - the most advanced electric units that utilize the heat pump and long-lasting heating elements with dry fire protection, electronic control panel for programming and troubleshooting.

With several models available, Voltex heat pumps from AO Smith do an excellent job in supplying plenty of hot water - up to 5 showers operating at the same time.

Most of the tank-type water heaters from AO Smith come with a warranty of 6 years, either budget-friendly models or advanced such as Vertex, while some, such as Polaris or Voltex, have a 10-year warranty.

Tankless have a more extended warranty from all of the tank-type gas and electric models - 15 years.

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About AO Smith

The AO Smith company is a leader in the water heating industry, building HVAC products for over 70 years. The company is well known for the quality and innovation in energy efficiency and tank protection, such as the glass lining, AO Smith's patented process, which is now a standard in the water heating industry.

AO Smith is the owner of several popular brands present today: State, Reliance, Maytag, American, GSW, and John Wood.

How to contact AO Smith:

Official website:

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