A.O. Smith GDHE-75
A.O. Smith GDHE-75
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A.O. Smith GDHE-75
A.O. Smith GDHE-75
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A.O. Smith - 75 Gal. Storage - 189 Gal. First Hour Delivery - 96% Thermal Efficiency - 0.86 UEF - Natural Gas Water Heater - Direct Vent



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*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
Ships Monday, Apr 15th
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$63 / Month
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A.O. Smith - 75 Gal. Storage - 189 Gal. First Hour Delivery - 96% Thermal Efficiency - 0.86 UEF - Natural Gas Water Heater - Direct Vent
A.O. Smith - 75 Gal. Storage - 189 Gal. First Hour Delivery - 96% Thermal Efficiency - 0.86 UEF - Natural Gas Water Heater - Direct Vent
Model: GDHE-75
Product Q&A
How-To Articles

Recommended Accessories

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Expert Recommended Accessories Selected by Ken, our Expert
Required Accessories 9
These accessories are required to properly setup/install this product.
Optional Accessories 10


Product Video Disclaimer: "PED is not responsible for any variances from the product in this video and the item you purchase. Please review all product specs prior to purchase."
    A.O. Smith continues to lead the way in residential and commercial water heating with close to 70 years of innovative hot water solutions. The GDHE-75 features A.O. Smith's latest in high efficiency, condensing gas water heating, with an unprecedented 96% Thermal Efficiency, it is designed to save you money. A spiral heat exchanger helps to keep combustion gasses in the unit longer to lengthen the heat transfer cycle. By positioning the exchanger in the middle of the unit, heat is distributed evenly and more efficiently. These features combined with an Ultra-Low NOx rating means this heater will lower your water heating costs and carbon footprint. With its 75 gallon tank and easy to read LCD display, the GDHE-75 is ready to fulfill all of your hot water needs.
  • Helical Coil Heat Exchanger
  • The GDHE line features a spiral heat exchanger that is positioned in the center of the unit, to distribute heat more evenly. It also allows the combustion gases to stay in the tank longer, lengthening the heat cycle and providing higher efficiency.
  • Ultra Low-NOx Emissions
  • The GDHE-75 is designed to qualify for the most stringent Low-NOx standards. These standards coincide with SCAQMD rules and other air quality management districts.
  • User-Friendly Electronic Interface
  • An easy to read controller gives you easy access to temperature settings, operating mode, and diagnostics to make sure your unit is running exactly how you want it. These heaters are also iCOMM compatible, allowing them to be monitored remotely.
  • Side-Mounted Hot and Cold Taps
  • These side mounted taps allow the heater to be installed and used in space heating/water heating applications.
  • Corrosion Protection
  • GDHE models have heavy-duty anodic protection and Blue Diamond
California residents see
WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm..
For more information go to: www.p65Warnings.ca.gov


specs product image PID-70005
Product Category
Water Heater - Tank
General Information
Gas Water Heater
Product Line
Product Category
Water Heater - Tank
Delivery Options
Pickup Only
Medium Learn More
Medium refers to the substance that carries heat through the heating system. Systems are either designed to use either Hot Water or Steam as a medium, and components are usually specific to one or the other.
Hot Water
Fuel Type Learn More
Fuel Type
To create heat, some form of fuel is required. Fuel Type specifies what the product uses as an input to create heat.
Natural Gas
Vent Type Learn More
Vent Type
Products that use combustion (burning) of fuel to create heat also create potentially dangerous gasses that need to be exhausted (AKA "Vented"). Depending on the product, venting can be done via a chimney, through a side wall, or use a second vent to provide fresh air to the appliance.
Direct Vent
Storage Type
Mount Type
Maximum Altitude
10100 Feet
Maximum Input Capacity Learn More
Maximum Input Capacity
The Maximum Input Capacity describes how quickly the appliance will use fuel when delivering it's maximum capacity. The units may change depending on the fuel being used.
100000 BTU
First Hour Delivery Learn More
First Hour Delivery
Sometimes called First Hour Rating, this is the number of gallons of hot water the heater can supply per hour when starting with a fully heated tank. The recovery of the water heater depends on your boiler's BTU and boiler output temperature.
189 Gallons
Continuous Recovery Rate
129 Gallons
Uniform Energy Factor Learn More
Uniform Energy Factor
Uniform Energy Factor (UEF) is a measurement of water heater energy efficiency. The higher the energy factor, the more efficient the water heater.
Ultra Low NOx Emissions Learn More
Ultra Low NOx Emissions
NOx is a byproduct of the combustion process, and it's output is regulated in some jurisdictions. Many regulators mirror SCAQMD rules, which regulate air quality for some parts of Southern California. Ultra Low NOx appliances emit less than 10-14 ng/J (nanogram per Joule) of NOx. Learn More
Electrical Data
60 Hz
Storage Volume
75 Gallons
Primary Vent Pipe Diameter
2 Inches
Cold Water Inlet
3/4 Inch
Hot Water Outlet
3/4 Inch
Product Height
65 1/4 Inches
Product Width
27 3/4 Inches
Product Depth
27 3/4 Inches
Product Weight
382 Pounds
Shipping Weight
382 Pounds
Energy Star Listed
CSA Listed
AHRI Certified
Warranty Information
Parts Warranty Learn More
Parts Warranty
A warranty is a safeguard from defects in manufacturing and can vary in length and terms. Some manufacturers require registration for extended warranty benefits, be sure to check out features and the warranty document. To see the manufacturer's warranty statement, click on the Manuals tab. Learn More
6 Years


A.O. Smith GDHE-75 Reviews & Ratings

Product Q&A

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Product Questions Answered by Ken, the eComfort Product Expert
How do I vent this water heater (intake and discharge)? Also, which materials do I need, and how do I size vent pipes (including terminations on both ends)?
Michael A. 
from New York 
January 19, 2018

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A.O. Smith - 75 Gal. Storage - 189 Gal. First Hour Delivery - 96% Thermal Efficiency - 0.86 UEF - Natural Gas Water Heater - Direct Vent
A.O. Smith GDHE-75
A.O. Smith GDHE-75
A.O. Smith GDHE-75
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