Whole House Tankless Water Heaters
A. O. Smith has been a leader in whole-house water heating solutions for over 80 years. With the addition of electric tankless and gas tankless whole-house water heaters, A. O. Smith continues to deliver innovative products that are built to last.
Rebates & Tax Credits
Up to $850 in Local Utility Rebates may be available in your area!
*Gas water heaters with UEF of 0.82 or higher OR with a thermal efficiency of at least 90%. Local utility rebates available in limited geographical areas. For information on the Federal Tax Credit, go to: energystar.gov. Check with your tax advisor for applicability. Offer details and expiration may vary. See Rebate Center for details.
What Our Customers Are Saying
Benefits of Tankless Water Heaters
Continuous Hot Water
Tankless water heaters deliver continuous hot water. If sized properly, you’ll never run out of hot water again.
A. O. Smith tankless water heaters heat your water only when you’re using it, reducing energy costs depending on your hot water usage.
Due to their significantly smaller size, tankless water heaters save a tremendous amount of space compared to a traditional water heater and can be mounted in various spaces around your home.
On-Demand Hot Water
The heating technology within A. O. Smith tankless water heaters provides on-demand hot water by heating the water when you need it.
Instant Hot Water
A. O. Smith tankless water heaters with built-in recirculation pumps offer instant hot water when installed with the proper piping.
Innovation & Reliability
A. O. Smith has a long, rich history of reliability and innovations that have led the water heating industry for decades.
How it Works
Whole-house tankless water heaters produced by A. O. Smith deliver hot water on demand and can help in reducing energy consumption for your home. Built with scale-reduction technology, both electric tankless and gas tankless whole-house water heaters perform with high efficiency and are built to serve a wide range of applications.
A whole-house tankless water heater is built to provide continuous hot water whenever you need it. When a hot water tap is turned on, water from your cold water pipe enters the water heater and passes through the heat exchanger. With an electric tankless product, the water passes over the heating elements, quickly heating the water to your desired temperature. The process is the same for a gas tankless water heater, but instead of heating elements powered by electricity the burner is fueled by a natural gas or liquid propane line. For all A. O. Smith tankless water heaters, a continuous supply of hot water is delivered to your home with ease.
Still Have Questions?
- How much does it cost to install a tankless hot water heater?
The cost of installation can vary depending on the current plumbing of your home. A. O. Smith recommends contacting a licensed contractor to begin the evaluation process.
- What size tankless water heater do I need for my house?
After evaluating your desired water supply, your home’s climate and current piping, a licensed contractor will be able to provide an exact recommendation for your home. Use the XPERT™ Product Selector to get an initial recommendation on which water heater would be right for your home.
- Where should I install a tankless water heater?
Electric tankless water heaters can be installed in any location within your home with the appropriate hookups. Their compact size frees up valuable space within your home. For gas tankless water heaters you will need to utilize specific venting, which will impact where you can install throughout your home.
- How do you vent a tankless water heater?
No venting is required for A. O. Smith whole-house electric tankless water heaters, but for gas tankless water heaters you will need to consult with your local plumbing contractor to determine the best venting for your home.
Whole House Gas Tank vs. Whole House Gas Tankless
Take a closer look at the advantages of each type of water heater.
Whole House Gas Tank Water Heaters
- Low initial investment
- Energy-efficient options
- Easy installation
- Wide range of tank sizes from 30 to 95 gallons
- Hot water storage supply
Whole House Gas Tankless Water Heaters
- Continuous hot water
- Energy efficient
- Space savings
- Environmentally friendly
- X3® Scale Prevention Technology on select models
Find A Local Water Heater Pro
A. O. Smith water heaters are professionally installed by local independent contractors.
Featured Whole House Tankless Water Heaters
- 97-gallon first hour rating
- 6-Year Warranty
- 199,000 BTU input
- 15-Year Warranty
- ENERGY STAR® certified
- 100-gallon first hour rating
- 6-Year Warranty
- 199,000 BTU input
- 15-Year Warranty
- 22 kW
- 5-Year Warranty
High-Efficiency Condensing Gas Tankless Water Heaters
Learn more about A. O. Smith’s full line of high-efficiency condensing gas tankless water heaters.
Non-Condensing Gas Tankless Water Heaters
Learn more about A. O. Smith’s full line of non-condensing gas tankless water heaters.
Electric Tankless Water Heaters
Learn more about A. O. Smith’s full line of Electric tankless water heaters.
Not sure which product is right for you?
Take our water heater selector quiz to find the correct water heater for your home.
Interested in Learning More?
Gas water heaters require venting upon installation. Learn more about how to choose the correct vent type for your home.
How Water Quality Affects Water Heaters
How can the quality of your water affect your water heater? Get tips and more information on water hardness, why it matters, and how to solve it.
Why Water Heater Size Matters
Consider what size of water heater is best for your needs. Review the factors you’ll need to weigh before making a decision.
Water Heaters and Safety
Discover the innovative design features A. O. Smith engineers use to keep your water heater both functional and safe for everyday use.
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 now matter where hot water is needed, A. O. Smith can provide a solution you can count on.