10 Best Tankless Gas Water Heaters 2025 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 Rinnai RX199iN is a highly efficient tankless gas water heater ideal for those seeking a reliable and space-saving hot water solution. With a flow rate of up to 11.1 gallons per minute (GPM), it can support multiple fixtures simultaneously, making it suitable for larger households or homes with high hot water demands. Its impressive BTU rating of 199,000 ensures rapid heating, and its energy efficiency with a UEF of 0.98 means lower utility bills over time.

One of the standout features of the RX199iN is its adaptability; it can be installed indoors or outdoors and operates on either natural gas or propane. This flexibility is enhanced by the Smart Sense gas control system, providing ease of use and efficient performance. The compact design, comparable to a small suitcase, allows for installation in various spaces without compromising on performance.

There are considerations to keep in mind. The installation process is best handled by professionals, which can add to the initial cost. Additionally, while the heater is efficient, users should verify that their home's ground water temperature aligns with the heater's capabilities for optimal performance. Access to Wi-Fi control features requires purchasing additional modules, which might be a drawback for some users seeking comprehensive smart home integration.

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.