10 Best Tankless Hot Water Heaters 2026 in the United States

The Rinnai RXP199iN is a versatile tankless water heater designed for both indoor and outdoor use, thanks to its Versa Vent system. It runs on either natural gas or propane, which adds flexibility depending on your fuel preference. With a strong flow rate of up to 11.1 gallons per minute, it can supply hot water to around seven fixtures simultaneously, making it suitable for medium to large households. Its energy efficiency is excellent, boasting a UEF (Uniform Energy Factor) of 0.98, which means it uses fuel very efficiently and can help reduce energy bills.

The built-in Smart-Circ recirculation pump is a smart feature that learns your hot water usage patterns and adjusts accordingly, improving efficiency and convenience by reducing wait times for hot water. The water heater is quite compact, about the size of a small suitcase, which helps save space during installation. However, it is fairly heavy at 58 pounds and requires professional installation, which could add to upfront costs. The maximum temperature is 140°F, which fits most household needs. While it offers WiFi connectivity through an optional Control-R module for remote monitoring and control, this is not included and must be purchased separately.

Customer reviews are positive, with a high rating around 4.6 out of 5, reflecting satisfaction with performance and reliability. This Rinnai model is a solid choice for those needing reliable, efficient, and flexible hot water delivery, especially if you want advanced features like smart recirculation and WiFi control. Be prepared for professional installation and consider the additional cost of the WiFi module if desired.

The Rinnai RE199eP is a propane-powered outdoor tankless water heater designed to deliver hot water efficiently without running out. It offers a strong flow rate of up to 9.8 gallons per minute, enough to supply several fixtures at once, which is great for larger households or homes with multiple simultaneous water demands. The heater runs on liquid propane and boasts a high heat output of 199,000 BTU, capable of heating water up to 140°F, making it suitable for colder climates where a significant temperature rise is needed. Its compact size, roughly the footprint of a small suitcase, helps save space in outdoor installations.

The system includes a useful LED display that shows service reminders and error codes, which simplifies maintenance and troubleshooting. Energy efficiency is addressed by heating water only when necessary, helping to reduce fuel use and utility costs. On the downside, this model is non-condensing, so it may be less efficient compared to condensing units that recover more heat from exhaust gases. Installation is best left to professionals, especially since it is designed for outdoor mounting and involves propane connections.

The warranty is solid, with up to 15 years on the heat exchanger, giving peace of mind about durability. However, the WiFi control module is not included and must be purchased separately if remote monitoring is desired. This heater is a strong choice for those looking for a reliable, high-capacity propane tankless water heater that balances performance and energy savings, especially in outdoor setups where space and installation conditions matter.

The Rinnai RX130iN tankless water heater is a versatile choice for anyone needing a reliable source of hot water without the bulk of a traditional tank. It delivers up to 7.1 gallons per minute, meaning it can comfortably supply hot water to multiple fixtures at once, which is great for larger households. This model runs on natural gas or propane, making it flexible depending on your fuel preference or availability. Its energy efficiency is excellent, with a high UEF rating of 0.97, so it uses fuel very efficiently, helping keep utility costs lower.

The unit is compact, about the size of a small suitcase, and can be installed indoors or outdoors, provided you use the correct venting accessories. This makes it a good fit for various home setups but professional installation is strongly recommended to ensure safety and proper operation. The maximum temperature reaches 140°F, which is sufficient for most household needs. The built-in Smart Sense gas control helps optimize performance and safety, while features like Quick Flush make maintenance easier.

The price and installation complexity might be higher compared to simpler models, and the WiFi control option requires an additional purchase. Although it is energy-efficient, it still requires a gas connection and a 120V power source for controls. If you want a steady supply of hot water, good energy savings, and flexibility in installation with a trusted brand backing, this Rinnai model is worth considering.