High Efficiency Condensing and Non-Condensing Gas Tankless Water Heaters
Engineered to deliver continuous hot water when you need it, propane and natural gas tankless water heaters are easily installed in tight spaces, including closets, bathrooms and even outdoors in appropriate climates.
Introducing the Adapt® Gas Tankless Family
In 2010, A. O. Smith introduced its full line of natural gas and propane tankless water heaters that continue to innovate. A. O. Smith's condensing natural gas and propane tankless water heaters are highly efficient. Available in both indoor and outdoor configurations, A. O. Smith's tankless models pair high efficiency with groundbreaking designs.
Adapt® NC (Non-Condensing)
Hot water only when needed with on-demand tankless
Zero yearly descaling with integrated X3® Scale Prevention Technology
Copper Heat Exchanger
Adapt® SC (Standard Condensing)
Hot water only when needed with on-demand tankless
Zero yearly descaling with integrated X3® Scale Prevention Technology
Dual copper & stainless steel heat exchangers
ENERGY STAR® Certified with up to .95 UEF
Save on installation with rebates & tax incentives
Adapt®+ Premium Condensing
Hot water only when needed with on-demand tankless
Zero yearly descaling with integrated X3® Scale Prevention Technology
Single heavy-duty stainless steel heat exchanger
ENERGY STAR® Certified with up to .95 UEF
Save on installation with rebates & tax incentives
Instant hot water with integrated recirculation pump
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X3® Scale Prevention Technology
Prevent scale build-up to reduce regular maintenance and extend the life of your water heater by up to 300%.
Rebates & Tax Credits
Rebate and incentive programs provide savings to consumers for the purchase of water heaters that meet certain energy efficiency standards.
Need Help From A Pro?
A. O. Smith water heaters are professionally installed by local independent contractors.
What Our Customers Are Saying
- 199,000 BTU input
- 15-Year Warranty
“I love not having to worry about running out of hot water."
- 199,000 BTU input
- 15-Year Warranty
“Bought this unit to replace another unit from a different manufacturer. Wish I went with A O Smith to start with."
- 4,500-watt elements
- 48-gallon first hour rating
- 10-Year Warranty
“Great unit – provides plenty of hot water for the family."
Benefits of Condensing Gas Tankless Water Heaters
Continuous Hot Water
Condensing gas tankless water heaters produce continuous, on-demand hot water for your home and can provide instant hot water when the model includes a recirculation pump.
Space Savings
A. O. Smith’s condensing tankless water heaters can be mounted in small or tight places both inside and outside of your home to better utilize and save space.
Energy Savings
Condensing tankless water heaters utilize the residual heat from the exhaust gases to make hot water. That higher efficiency operation means lower operating costs and energy savings.
How it Works
A condensing tankless water heater saves space and supplies continuous hot water for your home, but what separates a condensing unit from a non-condensing unit is its ability to utilize excess heat efficiently by using a second heat exchanger that increases the efficiency and produces more hot water. Because tankless water heaters do not store their water supply within a tank, water is heated rapidly when the water runs through the heat exchanger within the tankless unit. Condensation is formed when you use a second heat exchanger to capture and cool what would otherwise be wasted heat. This process of utilizing the excess heat rather than venting it out of the heater allows your condensing tankless unit to conserve more energy, resulting in a Uniform Energy Factor (UEF) of over 0.90 and producing more hot water than non-condensing tankless heaters. Paired with a 15-year limited warranty, an
A. O. Smith condensing tankless water heaters can provide years of hot water for your home.
Still Have Questions?
Condensing tankless water heaters offer higher efficiency with UEF ratings up to 0.95 compared to 0.82 for non-condensing models, resulting in lower operating costs. They capture 95% of produced heat and can use plastic PVC venting. Non-condensing models cost less upfront and have simpler installation, making them practical for budget-conscious buyers. Both provide continuous hot water and 15-year warranties. Choose based on your budget, efficiency priorities, and installation conditions.
Condensing refers to technology that uses a second heat exchanger to capture and reuse exhaust heat. As hot exhaust gases pass through the second heat exchanger, they cool and form condensation while transferring heat to incoming water. This captures 95% of produced heat, achieving efficiency ratings above 0.90 UEF. The cooled exhaust allows plastic PVC venting instead of metal, reducing installation complexity and operating costs.
Yes, condensing tankless water heaters produce condensation that requires proper drainage. As the second heat exchanger cools hot exhaust gases to capture their heat, moisture forms and must drain away safely. Your installer will connect a condensate drain line to an appropriate drainage point during installation to prevent water damage and maintain efficient operation.
The proper size of a tankless water heater depends on a number of variables, including type of appliances you own, number of people in your home, and incoming water temperature. You should discuss with your installer, but you can also consult our online XPERT™ Product Selector that can also be found as a downloadable app.
Product Comparison
*Many factors affect the actual performance of a water heater. This represents our closest approximation of your likely experience with this water heater in your local area, but actual performance may vary depending on factors beyond our ability to control or estimate.
Water Heater Selector Quiz
Need Help From A Pro?
A. O. Smith water heaters are professionally installed by local independent contractors.
Featured Condensing Gas Tankless Water Heaters
- ENERGY STAR® certified (0.95 UEF)
- 199,000 BTU input
- 15-Year Warranty
- ENERGY STAR® certified (0.95 UEF)
- 180,000 BTU input
- 15-Year Warranty
- ENERGY STAR® certified (0.95 UEF)
- 160,000 BTU input
- 15-Year Warranty
Interested in Learning More?
Why A. O. Smith?
A. O. Smith is a leading manufacturer of both residential and commercial water heating technologies, including the #1 most specified commercial water heater.
For more than 145 years, we’ve developed state-of-the art products that push new boundaries and improve the lives of our customers.
We combine cutting-edge technology with committed people who take pride in providing the very best support for our customers.
Our products are put through rigorous quality and endurance testing so no matter where hot water is needed, A. O. Smith can provide a solution you can count on.