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 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 Ranein Natural Gas Tankless Water Heater is a strong contender in the market for those seeking an outdoor tankless gas water heater. It offers a maximum flow rate of 5.3 GPM, which is suitable for a household with 3-5 outlet points, ensuring you can run multiple showers or appliances simultaneously without running out of hot water. The 130,000 BTU rating ensures a high heating capacity, making it effective for quick and efficient water heating.

Its high energy efficiency is bolstered by the automatic adjustment of the blower speed based on external conditions, optimizing gas combustion and ensuring safety with reduced noise levels and a longer lifespan. Additionally, the anti-freeze protection feature is a valuable inclusion for colder climates, preventing internal damage due to freezing.

However, it is important to note that this unit is not recommended for use at elevations over 2,000 feet, which may limit its applicability in higher altitude areas. Also, while it is easy to install with standard fittings and a compact design, the unit must be drained if not in use during cold weather to prevent damage. Another point to consider is its reliance on a 120V power supply, which should be accessible at the installation location. This water heater is an efficient and space-saving solution for many households, provided the installation requirements and altitude limitations are considered.