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 Rinnai RE199iN is a compact tankless gas water heater designed for indoor use, offering a strong flow rate of up to 9.8 gallons per minute (GPM), which means it can supply hot water to several fixtures at once without running out. This makes it suitable for medium to large homes where multiple taps or appliances need hot water simultaneously. With a high BTU rating of 199,000, it can provide a significant temperature rise, meaning it can heat colder water quickly to your desired temperature. Its non-condensing design is simpler but slightly less efficient compared to condensing units; however, it still features energy-saving technology by heating water only when needed, helping reduce energy waste. The unit is fairly compact, about the size of a small suitcase, making it easier to install even in tighter indoor spaces.

One feature that stands out is the LED display which offers maintenance reminders and error codes, helping with easier troubleshooting and upkeep. While it does not include a recirculation pump, there is a compatible model available for that if needed. Installation requires professional help due to venting needs and gas connections, which is typical for gas water heaters and ensures safety and optimal performance.

This product comes with a solid warranty—15 years on the heat exchanger and additional coverage on parts and labor—giving extra confidence in its durability. This Rinnai model is well suited for users looking for reliable, on-demand hot water with good flow and heating power, though they should be prepared for professional installation and understand it’s a non-condensing unit, which might mean slightly less energy efficiency compared to condensing models.