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

The Rinnai RE180eP is a solid choice if you want a reliable outdoor propane tankless water heater that delivers plenty of hot water at once. It offers a strong flow rate of up to 8.5 gallons per minute, meaning it can comfortably supply multiple fixtures like showers and sinks simultaneously. With a powerful 180,000 BTU rating, it can heat water quickly, which is great for colder climates or larger households. The maximum temperature is 140°F, which covers most household needs.

Energy efficiency is improved through its smart design that heats water only when you need it, helping save on fuel costs. The LED display is helpful for monitoring the unit’s status and receiving maintenance reminders, though WiFi control is optional and requires extra equipment. Installation should be done by a professional to ensure safety and proper operation, as recommended by the manufacturer.

In terms of size, it’s compact—about the size of a small suitcase—making it suitable for various outdoor spaces without taking up much room. It weighs around 50 pounds, so while not ultra-light, it’s still manageable for outdoor mounting. One downside to consider is that it’s a non-condensing model. This means it might not be as energy-efficient as condensing alternatives, potentially leading to slightly higher propane use over time. Also, without WiFi control included, some users might miss out on remote monitoring features. Given the professional installation requirement, there could be added setup costs. If you're looking for a dependable, high-capacity propane water heater for outdoor use, this model fits well by balancing strong heating power with smart energy-saving features, though it may come with a few trade-offs in efficiency and convenience compared to higher-end units.

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 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.