10 Best Tankless Gas Water Heaters 2025 in the United States

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 RTG-70DVLN-3 is an indoor tankless natural gas water heater designed to deliver continuous hot water with a maximum flow rate of 7 gallons per minute. This capacity allows it to support multiple simultaneous water uses, such as running a shower and dishwasher together, making it suitable for medium to larger households. It features an energy efficiency rating of 0.82, helping reduce gas consumption by heating water only when needed, which can lower energy bills. The unit includes hot-start programming to prevent cold water bursts, enhancing user comfort.

A notable feature is the LeakGuard system, which detects and prevents leaks to protect your home from potential water damage. Its compact dimensions (approximately 13.5 inches wide and 24.2 inches tall) and universal venting compatibility allow for flexible installation in various indoor spaces. While the 7 GPM flow rate meets the needs of most homes, households with very high water demand may require a higher capacity model. Being a non-condensing unit, it may have lower efficiency compared to condensing alternatives in certain climates.

The maximum water temperature reaches up to 140°F, which is adequate for most applications but should be considered based on individual preferences. This Rheem model offers a balance of solid performance, energy savings, and safety features, making it a practical choice for homeowners seeking reliable on-demand hot water without the size of a traditional tank.

The FOGATTI Natural Gas Tankless Water Heater offers a strong performance with a maximum flow rate of 8.1 GPM and a high BTU rating of 180,000, making it suitable for large households needing hot water from multiple points simultaneously. Its outdoor installation is a convenient feature, especially with its compact size (26.2" x 17.1" x 7.1") and easy installation process, taking up little space. The precise temperature control, ensuring water temperature within 1°F accuracy, adds to its appeal by providing consistent comfort across different seasons.

The energy efficiency rating (EF) of >0.81 indicates good energy-saving capabilities, although there are models with higher efficiency in the market. The built-in DC fan and weather-resistant design make it suitable for challenging outdoor conditions, and the inclusion of a remote control panel for indoor use is a thoughtful touch. On the downside, it requires proper venting and installation by a professional might be necessary to meet safety standards. The warranty is a mix of 2 years for the entire unit and 5 years for the heat exchanger, which is decent but not exceptional compared to some competitors offering longer coverage.

Certified by CSA, it meets safety and efficiency standards. Weighing 43.2 pounds, it is relatively lightweight for its category. This heater is ideal for users seeking a high-capacity, energy-efficient solution for their hot water needs with the benefit of outdoor installation and precise control.