10 Best Tankless Water Heaters 2025 in the United States

The Rinnai RXP199iN Condensing Smart Sense Tankless Water Heater offers impressive versatility, operating with either natural gas or propane and being suitable for both indoor and outdoor installations. With a flow rate of up to 11.1 GPM, it can handle multiple fixtures at once, making it ideal for larger households. Its compact size and modern design, which includes features like Quick Flush and Smart-Circ Intelligent Recirculation, enhance its efficiency and user-friendliness.

Additionally, the unit boasts a high energy efficiency factor of 0.98, translating to significant energy savings. The option for WiFi connectivity through the Control-R module adds to its smart appeal, although this module is not included with the water heater. Installation should be performed by a professional, which adds to the initial cost but ensures proper setup and operation. The unit's temperature rise and maximum output of 199,000 BTU make it suitable for demanding environments, but users should ensure their home’s infrastructure supports this capacity.

The warranty and support are implied to be robust through Rinnai's recommendation for professional installation and their central app for service and troubleshooting. This tankless water heater is best suited for those needing a high-performance, energy-efficient solution for a large household.

The Rinnai RX199iN is a robust tankless water heater that is designed for both indoor and outdoor installation, offering flexibility in its setup. With a flow rate of up to 11.1 gallons per minute, it effectively supports multiple fixtures simultaneously, making it a great choice for larger households or those with high hot water demands. Its high energy efficiency rating of UEF .98 means you can expect notable savings on energy bills over time, which is especially beneficial for eco-conscious users.

This model is powered by either natural gas or propane, catering to various fuel types, which adds to its versatility. The compact design, similar to a small suitcase, helps save space in your home, a feature that many customers find appealing.

Professional installation is recommended, which could add to the cost and effort involved in setting it up. While the Rinnai Central App offers support for setup and troubleshooting, the WiFi control module is sold separately, which might be an inconvenience for users looking for a fully integrated smart home solution. Potential buyers should evaluate their specific hot water needs against the maximum temperature output of 140 degrees Fahrenheit. The warranty and support options are also crucial to consider, as they ensure peace of mind and assistance should any issues arise.

The Stiebel Eltron Tempra 24 Plus is a solid choice for those in need of an electric tankless water heater suitable for whole-house applications. Its continuous flow technology ensures that you'll have an uninterrupted supply of hot water, which is a significant advantage for larger households or those with high hot water demands. The unit is compact and energy-efficient, featuring a design that doesn't require venting, which makes it a great option if space is limited. The energy savings monitor is a nice addition, allowing you to track your energy costs effectively.

One of the key strengths of the Tempra 24 Plus is its advanced flow control, which helps maintain consistent water temperatures even when multiple outlets are in use. This is particularly beneficial during peak usage times. The digital temperature display and preset memory buttons make it user-friendly, even for individuals who might not be tech-savvy.

However, there are a few drawbacks to consider. The unit requires a minimum electric service of 150 A, which may be a limitation for homes with older electrical systems. Installation might be tricky for DIY enthusiasts, as it typically requires a professional to handle the electric setup. Additionally, while the unit operates quietly, some users might find that the slight reduction in flow during high demand could be a minor inconvenience. The warranty provided, including a 7-Year Leakage and 3-Year Parts Warranty, adds a layer of confidence in its reliability. The Stiebel Eltron Tempra 24 Plus is a well-rounded option for those prioritizing efficiency and continuous hot water, though it's best suited for households ready for potential electrical upgrades.