Tank Water Heaters

The quick-to-install, easy-to-maintain choice for high-quality hot water.

A. O. Smith is a trusted, industry-leading water heater manufacturer with over 80 years of experience in the industry. We are proud to offer a wide variety of water heaters to meet your hot water needs. Best of all, our water heaters are equipped with up to a 10-year limited warranty—ensuring reliable hot water delivery in your home for many years to come.
A. O. Smith has a rich 145-year-old history and has positively contributed towards America’s product innovations and resilience as a nation.

“Great water heating system with plenty of hot water when you need it.”

—August, ProLine® Standard 50-Gallon Electric Tank Water Heater

Benefits of Tank Water Heaters

  • Children washing hands.

    Low Initial Cost

    Tank water heaters allow you to keep more money in your wallet through their low initial purchase, installation, and maintenance costs.

  • Filling a glass of water.

    Easy Installation

    The uncomplicated design of tank water heaters rarely requires wiring or piping modifications, resulting in a fast, easy installation process. A. O. Smith strongly recommends that you consult a professional installer.

  • Father brushing teeth with daughter.

    Hot Water Storage Supply

    Tank water heaters store a supply of hot water, making it available when you need it most.

A Closer Look

Diagram of the interior of a tankless water heater.

How do tank water heaters work?

Tank water heaters allow cold water to flow into the bottom of the tank through a “dip tube.” As the water starts to fill the tank, multiple temperature sensors throughout the tank continually measure the average temperature of the water. If the temperature drops too far below the set point as the new water enters the tank, the heating mechanism will turn on until the water has returned to the set point. If you use a gas power source, like natural gas or liquid propane, your tank water will be heated by a flame under the tank and a hot air flue running up through the center of the tank. Standard electric water heaters heat water with resistive wire heating elements immersed in the water of the tank. Hybrid electric heat pump water heaters use electricity to power a compressor and a condenser to efficiently transfer heat from the ambient air into the water. When hot water is needed, it exits the tank through a hot water outlet and is distributed to the home.

Both A. O. Smith tank and tankless water heaters can reliably deliver hot water in your home.

Tank water heaters are more affordable in price, installation and repair costs. They are easy to install and more likely to integrate into your home’s existing electrical and plumbing systems. With a tank water heater you will always have a supply of hot water even in the instance of a power outage.

Tankless water heaters are much smaller in size and offer great space savings. They can be easily installed in bathrooms, under sinks or in closets. With a tankless water heater you have on-demand access to continuous hot water. Their high efficiency operation boasts cost and energy savings.

A. O. Smith is dedicated to making water heaters that are built to last. While all A. O. Smith tank water heaters have a limited warranty lasting between 6 to 10 years, it is not uncommon to find water heaters that are still properly functioning well over a decade or more. When properly installed and maintained in locations with good water quality and pressure, A. O. Smith tank water heaters are built to last.

Tank water heaters should be flushed annually. Flushing the tank clears out sediment and mineral deposits that may have built up. This helps keep your water heater operating at maximum efficiency.

The signs it’s time to replace your tank water heater include when water is leaking from your tank, there is sediment in your water or the water is rust colored. Additionally if you hear banging, rumbling, cracking or popping and your water won't heat above 120 degrees Fahrenheit.

Knowing the size of your household and the frequency and duration of your hot water usage can help you determine what tank water heater size is right for you. By using the A. O. Smith XPERT Product Selector, you can answer multiple-choice questions to narrow down what options are best for your home’s hot water needs.

Tank water heaters can use the following power sources: electric, natural gas, propane, oil, and solar.

A tankless water heater

Gas Tank
Water Heaters

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Read Reviews

Explore both natural gas and propane tank varieties to see if they’re the right fit for your home.

Electric Tank
Water Heaters

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Read Reviews

Discover what model is right for your home. Compare energy efficiency, warranty length, and more.

A tankless water heater
A tankless water heater

Hybrid Electric Heat Pump
Tank Water Heaters

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Read Reviews

Read about their energy and cost savings and review what options are right for you.

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A. O. Smith water heaters are professionally installed by local independent contractors.


Not sure which water heater is right for you?

Use our product selector tool to choose the correct model for your home.

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Additional Reading

Contractor Resources

  • Screwdriver and wrench icon.

    Installation Guide

    Download our tank waterheater installation instructions.

    View Document
  • Set square icon.

    Resource Guide

    Match the flow rate to your customer’s needs.

    View Document
  • Overlapping arrows icon.

    Cross Reference Tool

    Search for NAECA-compliant replacement options.

    Use Tool