10 Best Propane Tankless Water Heaters 2026 in the United States

The Rinnai RX199iN Condensing Smart Sense Water Heater is a strong contender in the propane tankless water heater category. With a commendable flow rate of up to 11.1 gallons per minute (GPM), it can support multiple fixtures simultaneously, making it ideal for larger households or busy environments. Its impressive BTU rating of 199,000 ensures quick heating, allowing you to enjoy hot water without interruptions.

One of the standout features is its energy efficiency, boasting a UEF rating of .98. This means it uses energy effectively, potentially saving you money on utility bills over time. The compact size—similar to a small suitcase—makes it easy to install in various spaces, whether indoors or outdoors, thanks to the Versa Vent system.

There are some considerations. The need for professional installation is strongly recommended, which could add to your initial costs if you don’t have a suitable technician at hand. Additionally, while the Smart Sense gas control system offers modern convenience, it requires familiarity with the system, which might be a hurdle for some users. The Rinnai RX199iN does feature user-friendly aspects, including an easy-to-use interface and a Quick Flush feature for maintenance. However, it doesn’t come with WiFi control capabilities out of the box, which could be a letdown for those looking for smart home integration. The Rinnai RX199iN is an excellent choice for those needing a reliable, efficient, and powerful tankless water heater, particularly for medium to large homes, but be prepared for installation logistics and the learning curve that comes with its smart features.

The Rinnai RXP199iN is a robust propane tankless water heater that promises to cater to a wide range of hot water needs, making it ideal for larger households or properties with multiple fixtures operating simultaneously. With a flow rate of up to 11.1 gallons per minute (GPM) and a powerful BTU rating of 199,000, this unit can deliver a consistent supply of hot water without the risk of running out, which is a major plus for busy homes.

One of its standout features is its high energy efficiency, boasting a UEF rating of 0.98. This means it can help save on energy bills compared to traditional tank heaters. The Smart-Circ Intelligent Recirculation system is another highlight, as it learns your hot water usage patterns and optimizes the recirculation accordingly, ensuring hot water is available when you need it.

Installation flexibility is another strength; it can be installed both indoors and outdoors, which gives homeowners options based on their available space. The compact design, about the size of a small suitcase, makes it easy to fit in tighter areas without compromising performance. There are a few drawbacks to consider. First, professional installation is recommended, which may add to the initial cost. While this ensures a proper setup, it requires finding a qualified technician, which could be inconvenient for some users. Additionally, while it offers WiFi connectivity through the Control-R module, this feature is sold separately, potentially leading to extra expenses if you desire smart home integration.

The Rheem Liquid Propane Condensing Tankless Water Heater is designed for indoor use and offers a strong flow rate of up to 9 gallons per minute (GPM), suitable for most medium to larger households needing continuous hot water. Its 180,000 BTU rating enables quick and consistent water heating, supporting multiple fixtures without losing performance. This model provides temperature control from 100°F to 140°F, with a default of 120°F, allowing users to adjust according to comfort or safety preferences.

A notable feature is its high energy efficiency, aided by condensing technology and the Overheat Film Wrap, which helps prevent overheating and improves heat retention. Installation is relatively straightforward given its moderate size (about 18 inches wide and 24 inches tall) and wall-mount design, saving space compared to traditional tank heaters. However, like many propane units, it requires proper venting to safely expel combustion gases, so installation costs might be higher if venting adjustments are needed.

The unit is reliable, backed by a solid heat exchanger warranty of 15 years, though labor and parts coverage are shorter. It weighs about 60 pounds, so professional installation is recommended. While it doesn’t include smart (WiFi) controls, its electric ignition adds convenience over manual pilot lights. For those seeking a high-capacity, energy-efficient propane tankless water heater for consistent indoor hot water, Rheem’s model represents good value, with venting requirements and professional installation considerations factored in.