10 Best Tankless Gas Water Heaters 2026 in the United States

The Rinnai RXP199iN tankless water heater offers a notable blend of versatility and efficiency. Its capacity to deliver up to 11.1 GPM makes it suitable for households with high hot water demands, potentially serving up to seven fixtures simultaneously. This high flow rate, coupled with a substantial 199,000 BTU rating, ensures a consistent supply of hot water even during peak usage times. The energy efficiency factor (UEF) of .98 indicates the unit is highly efficient, contributing to lower energy bills over time and making it an eco-friendly choice.

Additionally, the unit's compact size, comparable to a small suitcase, facilitates flexible installation options, whether indoors or outdoors, thanks to the Versa Vent system and the Smart Sense gas control system accommodating both natural gas and propane. The Smart-Circ Intelligent Recirculation feature is a standout, learning your water usage patterns to optimize efficiency and convenience by scheduling pump and recirculation activities.

While the design is user-friendly with features like an easy-to-use interface and Quick Flush function, professional installation is strongly recommended. This might be a drawback for those looking for a DIY solution and could add to the initial setup cost. Another potential downside is the need for an additional Control-R module for WiFi connectivity, which isn't included with the unit. This water heater is ideal for larger homes or any setting requiring a substantial and steady hot water supply, especially for users who prioritize energy efficiency and modern conveniences.

The Rheem RTGH-95DVLN-3 is a strong contender in the tankless gas water heater category. With a flow rate of up to 9.5 gallons per minute (GPM) and a BTU rating of 199,900, it’s capable of supplying hot water for multiple outlets simultaneously, making it ideal for larger households. Its energy efficiency rating of 0.93 means you can expect decent savings on energy bills, which is a big plus for budget-conscious consumers. Additionally, the unit features an integrated digital display that allows for easy temperature adjustments, ranging from 100 to 140°F, catering to various user preferences.

The compact design—measuring 17.7" wide and 23.7" high—makes it suitable for installations in smaller spaces, while the electric ignition simplifies startup. The manufacturer also offers a solid warranty: 1 year for labor, 15 years for the heat exchanger, and 5 years on parts, providing peace of mind for your investment.

However, there are some considerations to keep in mind. The venting requirements may necessitate additional installation work, particularly if your home isn't already set up for it, which could add extra costs. Furthermore, while its high flow rate is impressive, actual performance can vary based on incoming water temperature and other factors; thus, customers in colder climates might experience lower output.

The Rheem Natural Gas Condensing Tankless Water Heater is designed for indoor use and offers a strong flow rate of up to 9 gallons per minute, which is suitable for medium to large households needing consistent hot water from multiple taps simultaneously. Its energy factor of 0.93 indicates excellent efficiency, meaning it uses gas economically and can help lower utility bills compared to less efficient models. With a high BTU rating of 180,000, it can handle a good temperature rise, providing hot water up to 140°F, adjustable to your comfort preferences. The unit is relatively compact, measuring about 17.7 inches wide and 23.7 inches high, making it easier to install in tighter indoor spaces.

It also features direct venting, which helps maintain safe indoor air quality by venting exhaust outside. Some convenient features include electric ignition for easy startup, a LED display for monitoring, and hot start programming that minimizes cold water bursts. The heater comes with solid warranties, especially a 15-year heat exchanger warranty, reflecting confidence in durability.

Installation requires a suitable venting setup that may need professional help, and the 1-year labor warranty is shorter than some competitors. Additionally, while the water temperature range fits most needs, it caps at 140°F, which might be a limitation if you prefer hotter water for specific uses. This model suits homeowners seeking an energy-efficient, reliable tankless heater with strong output for everyday use, especially in homes with moderate to high hot water demand.