Best AO Smith Gas Water Heaters Review

A review of the best of AO Smith gas water heaters for residential homes, and features to look for. Check out both tankless and conventional tank-type heaters with the advantages and benefits of both. The difference between cheaper and expensive models.

Model review

As the list of gas-powered water heaters from AO Smith is huge, this review will cover the best and most advanced models, either looking for the affordable one or shopping for the most advanced models with the state-of-the-art design.

What to look for on tank-type gas water heaters

As explained in this article (LINK), the main features that are included in most models are the Blue Diamond glass coating - provides tank protection against corrosion, Coregard anode rod - also protecting the metal tank, self cleaning dip tube - reduces the sediment build-up and self-powered electronic gas valve used for the enhance performance and diagnostics.

Best AO Smith gas water heaters

The best gas water heaters from AO Smith are designed with the commercial-grade components and include the condensing technology, advanced diagnostics, high or continuous water flow rate, state of the art technology, superior high efficiency and ultra low gas emission, for better environment protection. These models are coming from the ProLine XE series as shown in the review of 50-gal units below:

Vertex Power Vent GPHE-50

AO Smith Vertex Power Vent GPHE-50Vertex GPHE-50
  • Helical internal heat exchanger increases the energy efficiency to over 90%, which is higher than the efficiency found on conventional models.
  • Side mounted recirculation taps for combined space and potable water heating.
  • Intelli-vent gas valve with the premium-grade hot surface ignitor for durability, precised temperature control and diagnostics.
  • Two heavy duty anode rods for better corrossion resistance.
  • High First Hour Rating of 119 and Recovery Rate of 92 gallons.
AO Smith Vertex Power Direct Vent GDHE-50Vertex GDHE-50

Vertex Power Direct GDHE-50

  • Helical internal heat exchanger and condensing design for the efficiency of 96%.
  • Side mounted recirculation taps for combination space and potable water heating.
  • Advanced electronic control with LCD display, diagnostics and iCOMM remote control.
  • First Hour Rating of 100 gallons.


AO Smith PolarisPolaris
  • Condensing design and 96% thermal efficiency.
  • Modulating gas burner for lower energy consumption and increased comfort.
  • Helical internal heat exchanger.
  • Stainless steel construction for durability.
  • Advanced electronic control with large LCD display.
  • Recovery rate of over 165 GPH.
  • 10-year warranty.

Best affordable gas models to consider

High efficiency power vent

AO Smith ProLine XE Power VentProLine XE Power Vent
  • Versatile power vent system with the 3-position rotatable blower outlet.
  • System against flammable vapors.
  • Hot surface ignitor.
  • Improved gas valve design with LED.
  • Energy Star compliant.
  • Side connection.
  • First Hour Rating of 108 GPH.

Effex - high efficiency atmospheric vent

AO Smith EffexAO Smith Effex
  • Pressurized combustion system.
  • Simple vent installation.
  • LCD user interface to set and monitor the temperature and service diagnostics.
  • Non-sacrificial power anode rod.

Tankless review

AO Smith TanklessAO Smith Tankless

The best AO Smith gas water heaters with the tankless design utilize the following features; two strong and ultra efficient heat exchangers, condensing technology for the ultra-high energy efficiency of 0.95, built-in recirculation pump for faster hot water delivery and ultra low NOx for less pollution - all models are from the ProLine XE series.

The most powerfull model is ATI-540H, designed to deliver up to 10 GPM of hot water, enough to supply hot water to homes with up to 4 showers, or even more when using the Easy Link or Multi-Unit system. This tankless unit is small and compact and can be installed indoor with the power or power-direct venting system or outdoor, as ventless. It is also smart where the built-in advanced electronics monitors the whole operation while helping with the diagnostics system for easier troubleshooting.

All the units are equipped with the safety elements to protect the system from extreme temperatures, pressure and freezing, while the long warranty of 15 years provides piece of mind to the owners.


ProLine gas
Vertex gas
Effex gas
Infinity tankless
ProLine electric
Voltex heat pumps
Power vent
Direct vent
30-gal gas  comparison
40-gal gas  comparison
50-gal gas  comparison

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