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 Rinnai RX160iN tankless water heater is a solid choice if you want a compact and efficient unit that can serve multiple fixtures at once. It offers a high flow rate of up to 9 gallons per minute, which means it can comfortably supply hot water to about six taps simultaneously — great for larger households or homes with higher hot water demands. Its energy efficiency is excellent, with a UEF rating of 0.97, helping you save on energy bills compared to traditional water heaters.

One of its strong points is its flexibility: you can install it indoors or outdoors (with the necessary venting kit), and it works with both natural gas and propane thanks to its Smart Sense gas control system. The unit is also fairly compact, roughly the size of a small suitcase, making it easier to fit into limited spaces. Temperature rise capabilities allow it to deliver water heated up to 140°F, which suits most residential needs. Additionally, it includes handy features like a Quick Flush for easier maintenance and optional WiFi control if you want smart home integration.

Professional installation is recommended due to the complexity of gas plumbing and venting, which could add to initial costs. Also, the unit requires specific venting accessories for outdoor use, so check your installation location carefully. Rinnai is known for solid customer service. This unit is ideal for homeowners looking for a reliable, energy-efficient, and versatile tankless water heater that can handle multiple demands without taking up much space.