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 RX130iN tankless water heater is a versatile and efficient choice for those looking for a reliable hot water supply without the bulk of a traditional tank. It offers a solid flow rate of up to 7.1 gallons per minute, which means it can comfortably handle up to four fixtures running at the same time for a typical family’s needs. Its energy efficiency is impressive, with a Uniform Energy Factor (UEF) of 0.97, helping to keep your energy costs down while being environmentally friendly. This model runs on either natural gas or propane, giving you flexibility depending on what fuel source you have available.

Installation is quite adaptable—it can be mounted indoors or outdoors thanks to the Versa Vent system, but proper professional installation is recommended to ensure safety and optimal performance. The unit is compact, roughly the size of a small suitcase, so it won’t take up much space. Temperature can be controlled up to 140°F, suitable for various household uses. The inclusion of features like the Smart Sense gas control and Quick Flush function makes maintenance easier and improves operation. The WiFi control module is sold separately if you want remote management, and the heater weighs 54 pounds, which is something to consider for mounting.

With a strong customer rating of 4.6 out of 5 stars and backing from Rinnai’s support and warranty system, this model is well suited for homeowners who want dependable, efficient hot water with flexible fuel and installation options.

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.