AO Smith Vertex Water Heaters
Review and Buying Tips

Find out how AO Smith Vertex water heaters can provide considerable energy savings in residential water heating applications. Explore the most advanced features from Vertex and features that bring hot water production to a new level.

Vertex water heaters from the AO Smith manufacturer can be found in two sizes; 50 and 75 gallons, both coming from the Proline XE series, promoted as the “BEST”. Read further to see why.

Vertex is known for its condensing technology - a technology that provides continuous and ultra-efficient water heating, with less energy waste than conventional gas water heaters, low gas emission, and superior performance.

Vertex models have a similar footprint as the conventional water heaters, and since they utilize the same connections, they are easy to install and service - even when replacing the old unit.

Depending on the venting set up, there are two types of Vertex available, both with ultra-high energy efficiency and recovery:

  • Vertex Power Direct Vent model - GDHE series
  • Vertex Power Vent model - GPHE series

Vertex Power Direct Vent – GDHE series (Vertex 100)

Amazing specs

AO Smith Vertex water heaters from the GDHE series or Vertex 100 are power direct vent models available in two sizes; 50 and 75 gallons. Thanks to its fully-condensing design, these models can achieve an incredible 96% energy efficiency and provide significant savings to the homeowners. According to the manufacturer, the annual operating cost is around $200, which is lower than the cost found on most tank-type and tankless models.

An innovative design provides an ultra-efficiency and high recovery of up to 129 gallons. It includes the advanced helical coil heat exchanger, top-fired burner for high power of 100,000 BTU, and condensing operation. Condensing water heaters use the energy of the flue gases, so the temperature is lower, and venting is cheaper.

Another fantastic factor, which is essential when selecting a gas water heater, is the First Hour Rating of up to 130 gallons, making the Vertex 100 perfect for families with high demand for hot water. These models easily supply a sufficient amount of hot water up to 4-5 showers running at the same time, even hot tubs. Users can enjoy endless shower time.

Heat exchanger

Compared to the standard water tank heaters, which come with the straight flue tube, Vertex 100, with the helical heat exchanger design and increased surface area brings much better and efficient heat transfer and reduced sediment buildup.

The water heater uses sealed combustion to burn the natural gas or propane and sealed vents for venting flue gases out and draw the fresh air in.

Control panel

There is a large LCD control panel at the front of the Vertex 100 that provides information about the heating operation, has advanced diagnostic capabilities, monitors and controls the temperature more accurately.

Vertex models are compatible with the iCOMM, which allows them to monitor the operation from remote locations.

Quality elements

The metal tank is fully protected with the commercial-grade glass coating, which protects both the exchanger and metal tank, and two heavy-duty and commercial-grade anode rods to fight the corrosion. A dip tube which brings the water inside the tank is long-lasting and is designed for high temperatures, up to 400 F.


AO Smith Vertex 100 is an environment-friendly water heater equipped with an ultra-low NOx and top-fired gas burner that significantly reduces greenhouse gas emissions.


Flexibility allows AO Smith Vertex water heaters horizontal and vertical vent installation in a length of up to 128 feet, using the PVC, CPVC, ABS, or PP vents.

Thanks to the side water connections, units can be used not only for potable water heating but combination space and water heating.

GDHE models are certified for sea level to 10,100 feet elevation.

Vertex Power Vent model - GPHE series

From the Vertex Power Vent GPHE series, you can buy only one 50-gal gas water heater, which is also condensing and Energy Star approved. This model comes with an ultra-high thermal efficiency of 94%, a bit lower efficiency than the efficiency found on the previous two GDHE models but still higher than the efficiency found on conventional water tank heaters. As opposed to the GDHE series, the Vertex GPHE water heater is equipped with the Green Choice gas burner that uses natural gas only, and it complies with the low NOx gas emission standard.

The AO Smith Vertex GPHE-50 model utilizes a metal tank with a 50-gallon capacity, and it generates a power of 76,000 BTU, a recovery rate of 95 GPH, and a First Hour Rating of 119 gallons. It is recommended for average to large households, delivering hot water to two showers operating simultaneously, in the amount of 3-4 gallons per minute, and with the maximum shower time of 65 minutes.

As opposed to the GDHE series and two pipe sizes available, GPHE models can use vent pipes with 2, 3, and 4 inches in diameter that can run from 25 to 128 feet max.

GPHE models are certified for sea level to 5,300 feet elevation.


Model/Feature Vertex GPHE-50 Vertex GDHE-50 Vertex GDHE-75
Capacity (gal) 50 50 75
Power (BTU) 76,000 100,000 100,000
Efficiency 94% 96% 96%
First Hour Rating (GPH) 119 100 130
Size (inch) 71x21 67x22 65x28
Simultaneous showers 2 2 3
Shower time 65 min endless endless
Vent size
4”- 128ft
Warranty (years) 6 6 6


AO Smith Vertex models are extra performing gas water heaters designed for homeowners with a high demand for hot water. Compared to traditional water heaters, Vertex models use less fuel, have higher gas input, and superior thermal efficiency, which ensures lower operating costs.


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