10 Best Outdoor Tankless Water Heaters 2025 in the United States

The Rinnai RXP199iN is a highly efficient tankless water heater that can operate on either propane or natural gas, making it versatile in terms of energy source. With a flow rate of up to 11.1 gallons per minute (GPM), it can supply hot water for multiple fixtures simultaneously, which is great for larger households or outdoor uses where instant hot water is a necessity. Its BTU rating of 199,000 indicates strong heating performance.

The Rinnai RX199iN Condensing Smart Sense Tankless Water Heater is a solid choice for those seeking an efficient and high-capacity hot water solution for their home. With a flow rate of up to 11.1 gallons per minute (GPM), this heater can handle multiple fixtures simultaneously, making it ideal for larger households or homes with high hot water demand. Its 199,000 BTU rating ensures that it heats water quickly, maintaining a steady supply.

The Rinnai RX130iN tankless water heater is a solid choice for anyone needing a reliable hot water supply indoors or outdoors. It delivers up to 7.1 gallons per minute, which means it can handle around four fixtures running at the same time without running out of hot water. The 130,000 BTU rating indicates strong heating power capable of raising water temperature efficiently, even for larger households or homes with colder incoming water. One standout feature is its high energy efficiency, with a UEF of 0.97, meaning it uses fuel very effectively and can help save on energy bills. Installation is simplified by the Versa Vent system, allowing the unit to be safely installed indoors or outside, although outdoor installation requires an extra vent cap. Weather resistance is implied by its design for outdoor use, but professional installation is strongly recommended to ensure safety and longevity.