10 Best Outdoor Propane Tankless Water Heater 2026 in the United States

The Rinnai RXP199iN is a propane or natural gas tankless water heater designed for both indoor and outdoor use. It boasts an impressive flow rate of up to 11.1 gallons per minute (GPM), which is excellent for households with multiple fixtures needing hot water simultaneously. With a BTU rating of 199,000, it effectively heats water quickly, ensuring you won’t run out during peak usage times.

A standout feature is its high energy efficiency, rated at a UEF of .98, which means it uses energy wisely, potentially lowering your utility bills. The Smart Circ Intelligent Recirculation technology is a convenient addition, as it learns your hot water usage patterns, helping to minimize waste and keep hot water readily available.

While its compact size—similar to that of a small suitcase—makes it easy to install in various locations, professional installation is strongly recommended, which may add to your overall costs. The Rinnai Central App provides helpful tools for setup and troubleshooting, although the WiFi module is sold separately, which could be a drawback for those looking for a completely integrated smart system.

The Rheem RTG-95XLN-3 is a solid choice if you need a high-capacity outdoor propane tankless water heater that can supply enough hot water for your whole house, thanks to its 9.5 gallons per minute flow rate. It supports multiple simultaneous uses like showers and dishwashers without running out of hot water. One of its strengths is energy efficiency: it only runs when you need hot water, helping reduce energy bills, and the water-saving setting can save over 1,000 gallons of water annually. The hot-start programming feature keeps it ready to deliver hot water immediately, avoiding cold bursts that can be annoying in other models. It heats water up to 140 degrees Fahrenheit, which is typically sufficient for household needs.

The heater is designed for outdoor wall mounting and is smaller and lighter (about 39 pounds) compared to previous models, making installation easier and saving space. While it is efficient, it is non-condensing, which means it’s not the most efficient model available on the market. Safety features are standard but not extensively detailed, so users should ensure proper installation and ventilation. Also, it’s designed for natural gas but can be compatible with propane if set up correctly.

If you want a dependable, efficient outdoor water heater that delivers consistent hot water and saves energy and water, this model fits well. Keep in mind that it’s a high-demand appliance, so correct installation and maintenance are important for safe, long-lasting use.

The Rinnai RE199eP Non-Condensing Propane Tankless Water Heater is an efficient and powerful option for those needing an outdoor installation. With a flow rate of up to 7.6 GPM, it can handle multiple fixtures simultaneously, ensuring you never run out of hot water. This model is compact, comparable to the size of a small suitcase, making it portable and easy to install in various outdoor settings.

The 199,000 BTU rating ensures quick heating, and the energy-efficient design only heats water when necessary, conserving energy. It also features a handy LED display that provides service reminders and error codes, which can be very helpful for maintenance and troubleshooting. A significant strength is its durability, backed by a robust residential guarantee (15 years for the heat exchanger, 5 years for parts, and 1 year for labor). However, professional installation is recommended, which might add to the initial cost. Furthermore, while it offers WiFi control, this requires an additional Controlr module, which is not included. The heater's design also meets strict environmental standards, such as the South Coast Air Quality Management District NOx emission levels.

One potential drawback is its non-condensing nature, which might be less efficient in capturing and reusing heat compared to condensing models. Additionally, users should verify if this heater is suitable for their region based on ground water temperature. This unit is best suited for households looking for a reliable and energy-efficient outdoor water heating solution with high flow rates and modern features.