10 Best Outdoor Tankless Water Heaters 2026 in the United States
#1
Winner
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
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.
Rating
10.0
Chosen by1,362
Energy Efficiency
Installation and Venting
Most important from
116 reviews
#2
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
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.
Rating
9.7
Flow Rate (GPM)
Energy Efficiency
Temperature Rise
Most important from
133 reviews
#3
NEW Rinnai RX160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU
The Rinnai RX160iN is a versatile tankless water heater designed for both indoor and outdoor use, making it a flexible choice if you want installation options. It delivers up to 9 gallons per minute, enough to supply six fixtures at once, which should cover most household needs comfortably. Its high BTU rating of 160,000 means it can provide a strong temperature rise, keeping your water hot even in colder climates. The unit boasts an impressive energy efficiency rating (UEF 0.97), which helps save on energy bills over time. Installation requires a professional, especially for outdoor setups where the Versa Vent system and an outdoor vent cap are necessary for safe operation.
Rating
9.1
Energy Efficiency
Installation and Venting
Flow Rate (GPM)
Most important from
64 reviews
Top 10 Best Outdoor Tankless Water Heaters 2026 in the United States
#1
Winner
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
Flow Rate (GPM): 11.1
Energy Efficiency: UEF .98
BTU Rating: 199000
Installation and Venting: Professional, outdoor with proper venting
Durability and Weather Resistance: Durable, suitable for various environments
Chosen by 1362 this week
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
Flow Rate (GPM): 11.1
Energy Efficiency: .98 UEF
BTU Rating: 199000
Installation and Venting: Versa Vent, professional install
Warranty and Support: robust warranty and support
NEW Rinnai RX160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU
NEW Rinnai RX160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU
Flow Rate (GPM): 9 Gallons Per Minute
Energy Efficiency: 0.97
BTU Rating: 160,000
Installation and Venting: Indoor/outdoor; pro install; Versa Vent
Durability and Weather Resistance: Outdoor weather resistant if installed properly
Warranty and Support: Reliable warranty and support from Rinnai
NEW Rinnai RX130iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 7.1 GPM, 130,000 BTU
NEW Rinnai RX130iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 7.1 GPM, 130,000 BTU
Flow Rate (GPM): 7.1 gallons per minute
Energy Efficiency: UEF of 0.97
BTU Rating: 130,000 BTU
Temperature Rise: Max temperature 140°F
Installation and Venting: Versa Vent indoor/outdoor install
Durability and Weather Resistance: Outdoor use; extra protection needed
Warranty and Support: Warranty, online resources, installer network
Rinnai RE199eN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Rinnai RE199eN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Flow Rate (GPM): 7.6
Energy Efficiency: heats water only when necessary
BTU Rating: 199,000
Temperature Rise: significant rise
Installation and Venting: outdoor, professional installation recommended
Durability and Weather Resistance: withstand outdoor conditions
Warranty and Support: heat exchanger 15 years, labor 5 years
Related Products
Westinghouse Smart Outdoor Propane Tankless Water Heater, 8.1 GPM 180,000 BTU Whole Home Instant Hot Water Heater, ±1°F Temp Stability, Non-Condensing High Efficiency for 3-5 Fixtures
Westinghouse Smart Outdoor Propane Tankless Water Heater, 8.1 GPM 180,000 BTU Whole Home Instant Hot Water Heater, ±1°F Temp Stability, Non-Condensing High Efficiency for 3-5 Fixtures
Flow Rate (GPM): 8.1 Gallons Per Minute
Energy Efficiency: High Efficiency
BTU Rating: 180000 BTU
Installation and Venting: Outdoor wall mount, 3/4" connections
Durability and Weather Resistance: CSA certified, freeze protection, drain
Warranty and Support: 2 years unit, 5 years exchanger
Rheem RTG-95XELN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water Heater 9.5 GPM with WiFi, 199,900 BTUs
Rheem RTG-95XELN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water Heater 9.5 GPM with WiFi, 199,900 BTUs
Flow Rate (GPM): 9.5 Gallons Per Minute
Energy Efficiency: 0.82
Installation and Venting: Needs 1/2 inch gas line, venting
Durability and Weather Resistance: Weather-resistant, suitable for outdoor use
Rinnai RE140eP Non-Condensing Propane Tankless Water Heater, Up to 5.3 GPM, Outdoor Installation, 140,000 BTU
Rinnai RE140eP Non-Condensing Propane Tankless Water Heater, Up to 5.3 GPM, Outdoor Installation, 140,000 BTU
Flow Rate (GPM): 5.3
Energy Efficiency: High Efficiency
BTU Rating: 140,000
Installation and Venting: Outdoor Installation
Durability and Weather Resistance: For various outdoor conditions
Warranty and Support: 15-year warranty on heat exchanger
Rinnai RE140eN Non-Condensing Natural Gas Tankless Water Heater, Up to 5.3 GPM, Outdoor Installation, 140,000 BTU
Rinnai RE140eN Non-Condensing Natural Gas Tankless Water Heater, Up to 5.3 GPM, Outdoor Installation, 140,000 BTU
Flow Rate (GPM): 5.3 gallons per minute
Energy Efficiency: High
BTU Rating: 140,000
Temperature Rise: Strong temperature rise
Installation and Venting: Outdoor; professional installation recommended
Durability and Weather Resistance: Durable, compact, weather resistant
Warranty and Support: 15yr heat exchanger, 5yr labor, 1yr parts
#10
Ranein Propane Gas Tankless Water Heater, Outdoor Max 8.5 GPM, 190,000 BTU Instant Hot Water Heater
Ranein Propane Gas Tankless Water Heater, Outdoor Max 8.5 GPM, 190,000 BTU Instant Hot Water Heater
Flow Rate (GPM): 8.5 Gallons Per Minute
BTU Rating: 190000 British Thermal Units
Temperature Rise: 155 Degrees Fahrenheit
Installation and Venting: Wall mount; standard fittings; no high altitude
Durability and Weather Resistance: Anti-freeze protection; outdoor use
Warranty and Support: 2 Year Manufacturer
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Buying Guide for the Best Outdoor Tankless Water Heaters
Choosing the right outdoor tankless water heater can significantly enhance your comfort and convenience, especially if you live in an area where hot water is essential. Tankless water heaters provide hot water on demand, which means you don't have to wait for a tank to fill up and heat. This can save energy and reduce your utility bills. When selecting an outdoor tankless water heater, it's important to consider several key specifications to ensure you get the best fit for your needs.Flow Rate (GPM)Flow rate, measured in gallons per minute (GPM), indicates how much hot water the heater can produce at a given time. This is crucial because it determines whether the heater can meet your household's hot water demands. For example, a flow rate of 3-4 GPM is suitable for small households or single applications like a shower, while 7-10 GPM is better for larger households with multiple simultaneous hot water needs. Assess your household's hot water usage to choose the right flow rate.
Energy EfficiencyEnergy efficiency is measured by the unit's Energy Factor (EF) or Uniform Energy Factor (UEF). This spec indicates how efficiently the heater converts energy into hot water. Higher EF or UEF values mean better efficiency and lower operating costs. Look for models with high efficiency ratings if you want to save on energy bills and reduce your environmental footprint. Consider your usage patterns and prioritize efficiency if you use hot water frequently.
BTU RatingBTU (British Thermal Unit) rating measures the heater's heating capacity. Higher BTU ratings mean the heater can produce more hot water quickly. For larger households or colder climates, a higher BTU rating (e.g., 150,000-200,000 BTUs) is recommended to ensure a steady supply of hot water. For smaller households or warmer climates, a lower BTU rating (e.g., 100,000-150,000 BTUs) may be sufficient. Match the BTU rating to your hot water needs and climate conditions.
Temperature RiseTemperature rise refers to the increase in water temperature that the heater can achieve. This is important because it affects how hot the water will be when it reaches your tap. If you live in a colder area where the incoming water temperature is low, you'll need a heater with a higher temperature rise capability. Typically, a temperature rise of 50-70 degrees Fahrenheit is adequate for most households. Consider your local water temperature and desired hot water temperature to choose the right model.
Installation and VentingOutdoor tankless water heaters require proper installation and venting to ensure safe and efficient operation. Some models are easier to install and come with venting kits, while others may require professional installation. Consider the complexity of installation and whether you are comfortable doing it yourself or if you need professional help. Proper venting is crucial to prevent carbon monoxide buildup and ensure the heater operates efficiently. Check the installation requirements and choose a model that fits your installation capabilities.
Durability and Weather ResistanceSince outdoor tankless water heaters are exposed to the elements, durability and weather resistance are important factors. Look for models with robust construction, corrosion-resistant materials, and weatherproof features to ensure longevity. Some heaters come with protective enclosures or are designed to withstand extreme temperatures. If you live in an area with harsh weather conditions, prioritize models with high durability and weather resistance to ensure reliable performance.
Warranty and SupportA good warranty and reliable customer support can provide peace of mind and protect your investment. Warranties typically cover parts and labor for a certain period, and longer warranties indicate confidence in the product's quality. Check the warranty terms and the availability of customer support services. Choose a model with a comprehensive warranty and good support to ensure you can get help if any issues arise.