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10 Best Tankless Water Heaters 2025 in the United States
#1
Winner
NEW Rinnai RXP199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU, with Recirculation Pump
The Rinnai RXP199iN Condensing Smart Sense Tankless Water Heater offers impressive versatility, operating with either natural gas or propane and being suitable for both indoor and outdoor installations. With a flow rate of up to 11.1 GPM, it can handle multiple fixtures at once, making it ideal for larger households. Its compact size and modern design, which includes features like Quick Flush and Smart-Circ Intelligent Recirculation, enhance its efficiency and user-friendliness.
Rating
10.0
Chosen by1,161
Flow Rate
Energy Efficiency
Fuel Type
Most important from
295 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 is a robust tankless water heater that is designed for both indoor and outdoor installation, offering flexibility in its setup. With a flow rate of up to 11.1 gallons per minute, it effectively supports multiple fixtures simultaneously, making it a great choice for larger households or those with high hot water demands. Its high energy efficiency rating of UEF .98 means you can expect notable savings on energy bills over time, which is especially beneficial for eco-conscious users.
Rating
9.1
Flow Rate
Energy Efficiency
Size and Installation
Most important from
295 reviews
#3
FOGATTI Natural Gas Tankless Water Heater Outdoor - Max 8.1 GPM 180,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 180S Series
The FOGATTI Natural Gas Tankless Water Heater is a solid choice for those looking for an efficient way to get instant hot water for multiple sources in their home. With a high flow rate of up to 8.1 gallons per minute (GPM) and a heating capability of 180,000 BTU, it can easily meet the demands of a large family. One of its standout features is its outdoor installation, which saves space indoors and is equipped with a remote control panel for convenient indoor operation.
Rating
7.9
Flow Rate
Size and Installation
Warranty and Support
Most important from
177 reviews
Top 10 Best Tankless Water Heaters 2025 in the United States
#1
Winner
NEW Rinnai RXP199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU, with Recirculation Pump
NEW Rinnai RXP199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU, with Recirculation Pump
Flow Rate: 11.1 GPM
Energy Efficiency: 0.98
Fuel Type: Natural gas or propane
Size and Installation: 19"W x 31"H, Wall mount
Chosen by 1161 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: 11.1 GPM
Energy Efficiency: UEF .98
Fuel Type: Natural gas or propane
Size and Installation: 18.5"W x 30.11"H, Wall mount
Temperature Rise: 140 Degrees Fahrenheit
FOGATTI Natural Gas Tankless Water Heater Outdoor - Max 8.1 GPM 180,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 180S Series
FOGATTI Natural Gas Tankless Water Heater Outdoor - Max 8.1 GPM 180,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 180S Series
Flow Rate: 8.1 Gallons Per Minute
Energy Efficiency: >0.81
Fuel Type: Natural Gas
Size and Installation: 17.1"W x 26.2"H, Wall-Mounted
Warranty and Support: 2-year unit, 5-year heat exchanger
Rheem RTGH-95DVLN-3 RTGH Series 9.5 GPM 199,900 BTU 120 Volt Residential Indoor Natural Gas Tankless Water Heater Stainless Steel
Rheem RTGH-95DVLN-3 RTGH Series 9.5 GPM 199,900 BTU 120 Volt Residential Indoor Natural Gas Tankless Water Heater Stainless Steel
Flow Rate: 9.5 GPM
Energy Efficiency: 0.93
Fuel Type: Natural Gas
Size and Installation: 17.7"W x 23.7"H, Wall-mounted
Temperature Rise: 100 to 140°F
Warranty and Support: 1-year labor, 5-year parts
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: 9 gallons per minute
Energy Efficiency: 0.97
Fuel Type: natural gas and propane
Size and Installation: 19"W x 31"H, indoor/outdoor venting
Temperature Rise: up to 140°F
Related Products
Up to 14% off
Stiebel Eltron Tankless Water Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
Flow Rate (Gallons Per Minute - GPM): 1.5 Gallons Per Minute
Energy Source (Gas vs. Electric): Electric
Installation Requirements: Wall mount; pro installation recommended
Size and Dimensions: 16.63"W x 14.5"H
Maintenance Needs: Periodic descaling in hard water
Rinnai CX199iN Condensing Smart Sense Commercial Natural Gas or Propane Tankless Water Heater, 199,000 BTU, 11.1 GPM
Rinnai CX199iN Condensing Smart Sense Commercial Natural Gas or Propane Tankless Water Heater, 199,000 BTU, 11.1 GPM
Flow Rate: 11.1 GPM
Energy Efficiency: 96%
Fuel Type: Natural Gas or Propane
Size and Installation: 18.5"W x 30.11"H, Wall Mount
Rheem 18kW 240V Tankless Electric Water Heater, Gray
Rheem 18kW 240V Tankless Electric Water Heater, Gray
Flow Rate: 4.4 GPM
Energy Efficiency: Advanced self-modulation tech
Fuel Type: Electric
Size and Installation: 14.5"W x 18.25"H, 3/4 inch NPT
Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 9.5 GPM, 199,900 BTUs
Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 9.5 GPM, 199,900 BTUs
Flow Rate: 9.5 gallons per minute
Energy Efficiency: 0.82
Fuel Type: Natural Gas
Size and Installation: 13.5" x 24", wall-mounted, indoor
Temperature Rise: Max 140°F
#10
Rinnai RE180iN Non-Condensing Natural Gas Tankless Water Heater, Up to 8.5 GPM, Indoor Installation, 180,000 BTU
Rinnai RE180iN Non-Condensing Natural Gas Tankless Water Heater, Up to 8.5 GPM, Indoor Installation, 180,000 BTU
Flow Rate: 8.5 GPM
Energy Efficiency: 0.82
Fuel Type: Natural Gas
Size and Installation: 14.05"W x 27.28"H, Wall
Warranty and Support: Up to 15 years
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Buying Guide for the Best Tankless Water Heaters
Choosing a tankless water heater can be a smart way to ensure you have hot water on demand without taking up much space or worrying about running out. Unlike traditional heaters with storage tanks, tankless models heat water only when it's needed, making them energy-efficient and generally more durable over time. To find the best fit for your household, it's essential to understand the main specifications and features, as these will directly affect your experience and satisfaction.Flow Rate (Gallons Per Minute - GPM)Flow rate measures how much hot water the unit can provide at once, typically shown in gallons per minute (GPM). This is important because if the flow rate is too low, you might struggle to use hot water in multiple places at the same time (like a shower and kitchen sink). Lower GPM units (around 2-4 GPM) work well for small households or single fixtures, while larger homes or those who need hot water at several points at once should look at higher GPM units (6+ GPM). To pick the right flow rate, add up the GPM of appliances you normally use together at peak times; choose a model that covers your total need.
Temperature RiseTemperature rise tells you how much a heater can increase the water's temperature as it flows through. This matters because the incoming water is colder in some places or during certain seasons. Units are rated based on how much they can heat the water at a given flow rate. If you live in a colder area, or want extra-hot showers, choose a model that can deliver a higher temperature rise at your required flow rate. Manufacturers often provide charts; match your expected flow and local cold water temperature to select the right fit.
Energy Source (Gas vs. Electric)Tankless water heaters can be powered by natural gas, propane, or electricity. Gas models usually provide higher flow rates and can keep up with larger demand, while electric models are often more compact and easier to install in smaller spaces. The choice comes down to what's available in your home and your hot water use. If you need high capacity or already have a gas line, gas may be better. For smaller needs, or if you want a simpler setup, electric could be the way to go.
Installation RequirementsInstallation involves factors like ventilation for gas models, electrical capacity for electric ones, and space for fitting the unit on a wall. Gas models need proper venting to the outside, which can add to the installation steps, while electric heaters often require an upgraded electrical panel. Consider what's easier and feasible in your home; if your installation location can't easily be adapted, that should guide your choice.
Size and DimensionsWhile tankless heaters are much smaller than traditional tanks, they still come in different sizes. Size affects where you can place your unit, especially if you want to install it in a tight spot, like under a sink or in a closet. Measure your available space and make sure the unit you pick will fit comfortably, including space for any necessary maintenance.
Maintenance NeedsTankless units generally need less day-to-day attention than tanks, but they should still be cleaned (descaled) annually, especially if you have hard water. Some models make this easier than others. If you want minimal hassle, look for units with simple maintenance requirements and easy access for servicing. Think about your ability and willingness to keep up with maintenance when making your choice.