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10 Best Tankless Gas 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 tankless water heater offers a notable blend of versatility and efficiency. Its capacity to deliver up to 11.1 GPM makes it suitable for households with high hot water demands, potentially serving up to seven fixtures simultaneously. This high flow rate, coupled with a substantial 199,000 BTU rating, ensures a consistent supply of hot water even during peak usage times. The energy efficiency factor (UEF) of .98 indicates the unit is highly efficient, contributing to lower energy bills over time and making it an eco-friendly choice.
Rating
10.0
Chosen by1,290
Flow Rate (GPM)
Energy Efficiency (EF Rating)
Size and Installation Space
Most important from
297 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 highly efficient tankless gas water heater ideal for those seeking a reliable and space-saving hot water solution. With a flow rate of up to 11.1 gallons per minute (GPM), it can support multiple fixtures simultaneously, making it suitable for larger households or homes with high hot water demands. Its impressive BTU rating of 199,000 ensures rapid heating, and its energy efficiency with a UEF of 0.98 means lower utility bills over time.
Rating
7.9
Flow Rate (GPM)
Size and Installation Space
Most important from
297 reviews
#3
Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 9.5 GPM, 199,900 BTUs
The Rheem RTG-95DVLN-3 is a solid choice for those seeking a tankless gas water heater that can supply continuous hot water to an entire household. With a maximum flow rate of 9.5 gallons per minute, it can handle simultaneous use of showers, dishwashers, or other appliances without running out of hot water. Its energy factor rating of 0.82 means it operates with good efficiency, turning on only when hot water is needed, which helps save on energy bills. The hot-start programming feature keeps water warm and ready, reducing the annoying cold bursts when you first turn on the tap. This model also includes LeakGuard technology to detect internal leaks early, protecting your home from water damage—a useful safety feature.
Rating
7.6
Flow Rate (GPM)
Venting Requirements
Most important from
143 reviews
Top 10 Best Tankless Gas 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 (GPM): 11.1 GPM
Energy Efficiency (EF Rating): .98
BTU Rating: 199000
Venting Requirements: Versa Vent system
Size and Installation Space: 19"W x 31"H
Chosen by 1290 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 GPM
Energy Efficiency (EF Rating): UEF 0.98
BTU Rating: 199000
Venting Requirements: Versa Vent
Size and Installation Space: 18.5"W x 30.11"H
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 (GPM): 9.5 gallons per minute
Energy Efficiency (EF Rating): 0.82
Venting Requirements: Proper venting for non-condensing heaters
Size and Installation Space: 13.5"W x 24.2"H; compact indoor mount
Temperature Rise: Up to 140°F
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 (EF Rating): 0.97 EF rating
BTU Rating: 160,000 BTU
Venting Requirements: Versa Vent system
Size and Installation Space: 19"W x 31"H wall mount
Temperature Rise: High temperature rise
Rheem RTG-84DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 8.4 GPM, 180,000 BTUs
Rheem RTG-84DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 8.4 GPM, 180,000 BTUs
Flow Rate (GPM): 8.4 gallons per minute
Energy Efficiency (EF Rating): 0.82
Venting Requirements: universal venting compatible
Size and Installation Space: 13.5"W x 24.2"H
Related Products
FOGATTI Natural Gas Tankless Water Heater Indoor - Max 7.5 GPM 170,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 170S Series
FOGATTI Natural Gas Tankless Water Heater Indoor - Max 7.5 GPM 170,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 170S Series
Flow Rate (GPM): 7.5 Gallons Per Minute
BTU Rating: 170000 BTU
Venting Requirements: Must meet gas venting requirements
Size and Installation Space: 17.1"W x 26.2"H, compact unit
Temperature Rise: Precise control within 1 degree
Rinnai RE160iN Non-Condensing Natural Gas Tankless Water Heater, Up to 6.6 GPM, Indoor Installation, 160,000 BTU
Rinnai RE160iN Non-Condensing Natural Gas Tankless Water Heater, Up to 6.6 GPM, Indoor Installation, 160,000 BTU
Flow Rate (GPM): 6.6
Energy Efficiency (EF Rating): 0.81
BTU Rating: 160,000
Venting Requirements: Proper venting, professional installation
Size and Installation Space: Compact, wall mount, vent clearance
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 (GPM): 8.1
Energy Efficiency (EF Rating): >0.81
BTU Rating: 180,000
Venting Requirements: Proper venting required
Size and Installation Space: 26.2" x 17.1" x 7.1"
Rheem IKONIC RECTGH-SR11iP Professional Grade Super High Efficiency Condensing Tankless Liquid Propane Water Heater with Recirculation, 11.2 GPM
Rheem IKONIC RECTGH-SR11iP Professional Grade Super High Efficiency Condensing Tankless Liquid Propane Water Heater with Recirculation, 11.2 GPM
Flow Rate (GPM): 11.2 gallons per minute
Venting Requirements: Requires proper venting for gas operation
Size and Installation Space: 17.31"W x 28.56"H, compact size
Temperature Rise: Max temperature 140°F
#10
NEW Rinnai RXP160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU, with Recirculation Pump
NEW Rinnai RXP160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU, with Recirculation Pump
Flow Rate (GPM): 9 gallons per minute
Energy Efficiency (EF Rating): 0.97 EF rating
BTU Rating: 160000 BTU
Venting Requirements: Professional install; outdoor needs vent cap
Size and Installation Space: 19"W x 31"H; wall-mounted
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Buying Guide for the Best Tankless Gas Water Heaters
Choosing the right tankless gas water heater can significantly improve your home's energy efficiency and ensure you have a reliable supply of hot water. Tankless water heaters heat water on demand, which means they don't store hot water like traditional tank heaters. This can save you money on energy bills and provide an endless supply of hot water. However, selecting the right model involves understanding several key specifications to ensure it meets your household's needs.Flow Rate (GPM)Flow rate, measured in gallons per minute (GPM), indicates how much hot water the unit 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 with one or two fixtures running simultaneously, while larger households with multiple fixtures may require a flow rate of 7-10 GPM. To choose the right flow rate, consider the number of people in your home and the number of hot water fixtures you expect to use at the same time.
Energy Efficiency (EF Rating)The Energy Factor (EF) rating measures the efficiency of the water heater in converting fuel into hot water. A higher EF rating means the unit is more efficient, which can lead to lower energy bills. EF ratings typically range from 0.8 to 0.99. For those looking to maximize energy savings, a higher EF rating is preferable. However, even a mid-range EF rating can offer significant improvements over traditional tank water heaters. Consider your energy consumption habits and prioritize higher EF ratings if reducing energy costs is a primary concern.
BTU RatingBTU (British Thermal Unit) rating measures the heating capacity of the water heater. Higher BTU ratings mean the unit can heat water more quickly and handle higher flow rates. BTU ratings for tankless gas water heaters typically range from 120,000 to 199,000 BTUs. If you have a large household or high hot water demand, a higher BTU rating will ensure you have enough hot water. For smaller households or lower hot water usage, a lower BTU rating may be sufficient and more cost-effective.
Venting RequirementsTankless gas water heaters require proper venting to expel combustion gases safely. There are two main types of venting: direct vent and power vent. Direct vent systems draw air from outside and are ideal for homes with limited indoor ventilation, while power vent systems use indoor air and require an exhaust fan. The choice between these depends on your home's layout and existing ventilation infrastructure. Ensure you understand your home's venting capabilities and choose a model that aligns with them to ensure safe and efficient operation.
Size and Installation SpaceTankless gas water heaters are generally more compact than traditional tank heaters, but they still require adequate space for installation and maintenance. Consider the dimensions of the unit and the available space in your home. Ensure there is enough clearance around the unit for proper ventilation and access for maintenance. If space is limited, look for more compact models designed for tight installations. Proper sizing and placement are crucial for both performance and safety.
Temperature RiseTemperature rise refers to the difference between the incoming cold water temperature and the desired hot water temperature. This is important because it affects the heater's ability to provide consistent hot water. For example, if your incoming water temperature is 50°F and you want it heated to 120°F, the required temperature rise is 70°F. Different models have varying capabilities for temperature rise, so choose one that can handle the temperature rise needed for your region and usage patterns. Consider the climate you live in and the typical temperature of your incoming water when making your selection.