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10 Best Tankless Water Heaters 2025 in the United States

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Our technology thoroughly searches through the online shopping world, reviewing hundreds of sites. We then process and analyze this information, updating in real-time to bring you the latest top-rated products. This way, you always get the best and most current options available.

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Our Top Picks

#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

Rating
10.0
Chosen by1,254
Flow Rate
Energy Efficiency
Fuel Type

Most important from
234 reviews

Flow Rate
Powerful enough to provide hot water simultaneously at four places in a household of five or more.
Energy Efficiency
For maximum energy efficiency, the BLE Bluetooth button accessory is recommended to activate the water recirculation cycle, saving lots of water and energy.
Fuel Type
Supports both natural gas and propane, making it versatile for different household setups.
Size and Installation
Installation is straightforward with the excellent, detailed instruction manual, though pre-planning for mounting location, materials, and electrical service is advised.
Warranty and Support
While the quick start guide can be confusing, the manufacturer's tech support is very helpful for resolving issues.

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.

Additionally, the unit boasts a high energy efficiency factor of 0.98, translating to significant energy savings. The option for WiFi connectivity through the Control-R module adds to its smart appeal, although this module is not included with the water heater. Installation should be performed by a professional, which adds to the initial cost but ensures proper setup and operation. The unit's temperature rise and maximum output of 199,000 BTU make it suitable for demanding environments, but users should ensure their home’s infrastructure supports this capacity.

The warranty and support are implied to be robust through Rinnai's recommendation for professional installation and their central app for service and troubleshooting. This tankless water heater is best suited for those needing a high-performance, energy-efficient solution for a large household.

Rating
10.0
Chosen by1,254
Flow Rate
Energy Efficiency
Fuel Type

Most important from
234 reviews

Flow Rate
Powerful enough to provide hot water simultaneously at four places in a household of five or more.
Energy Efficiency
For maximum energy efficiency, the BLE Bluetooth button accessory is recommended to activate the water recirculation cycle, saving lots of water and energy.
Fuel Type
Supports both natural gas and propane, making it versatile for different household setups.
Size and Installation
Installation is straightforward with the excellent, detailed instruction manual, though pre-planning for mounting location, materials, and electrical service is advised.
Warranty and Support
While the quick start guide can be confusing, the manufacturer's tech support is very helpful for resolving issues.
#2

Rheem RTGH-95DVLN-3 RTGH Series 9.5 GPM 199,900 BTU 120 Volt Residential Indoor Natural Gas Tankless Water Heater Stainless Steel

Rating
10.0
Flow Rate
Size and Installation
Temperature Rise

Most important from
129 reviews

Flow Rate
Kitchen is 50+ feet away, and the water heats up faster than the tank heater it replaced.
Size and Installation
The unit is larger than some, but not as heavy as most. The installation was fairly straightforward.
Temperature Rise
Once all the plumbing was complete, we plugged it in and only had to adjust the temperature up 5 degrees. It's running great and has had no issues.

The Rheem RTGH-95DVLN-3 is a solid choice for those in need of a tankless water heater, especially for residential use. With a flow rate of up to 9.5 gallons per minute, it can easily meet the hot water demands of larger households or simultaneous usage across multiple fixtures. Its energy efficiency rating of 0.93 ensures that it operates economically, which can translate to lower energy bills over time.

One standout feature is the integrated digital display, making it easy to monitor and adjust temperature settings, which range from 100 to 140 degrees Fahrenheit. This adaptability allows users to find a comfortable temperature that suits their needs. Additionally, the natural gas fuel type is generally more efficient than electric options, further enhancing its appeal.

On the downside, installation can be a bit tricky if you're not familiar with gas appliances. It requires a wall-mounted setup and adequate venting, which might necessitate professional installation, adding to the cost. The warranty coverage, while decent with a 1-year labor and 5-year parts warranty, might be considered lacking compared to competitors that offer longer terms.

Another point to consider is that the heater's weight (about 59.9 pounds) and size (17.7”W x 23.7”H) may pose challenges during installation, especially in tighter spaces. It’s essential to ensure that your home can accommodate this unit before purchasing.

The Rheem RTGH-95DVLN-3 is a robust option for families seeking efficient hot water solutions. Its high flow rate and energy efficiency make it a strong contender in the tankless water heater market, but potential buyers should weigh the installation requirements and warranty duration against their specific needs.

Rating
10.0
Flow Rate
Size and Installation
Temperature Rise

Most important from
129 reviews

Flow Rate
Kitchen is 50+ feet away, and the water heats up faster than the tank heater it replaced.
Size and Installation
The unit is larger than some, but not as heavy as most. The installation was fairly straightforward.
Temperature Rise
Once all the plumbing was complete, we plugged it in and only had to adjust the temperature up 5 degrees. It's running great and has had no issues.
#3

Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2

Rating
9.9
Flow Rate
Energy Efficiency
Size and Installation

Most important from
2120 reviews

Flow Rate
What truly sets this heater apart is its ability to provide a continuous flow of hot water, even with multiple outlets in use.
Energy Efficiency
This tankless water heater's performance has exceeded my expectations in terms of convenience and efficiency.
Size and Installation
The unit is impressively quiet, and its space-saving design is a game-changer.
Temperature Rise
The temperature control is precise, ensuring you get the hot water you desire without any fuss.

The Stiebel Eltron Tempra 24 Plus is a solid choice for those in need of an electric tankless water heater suitable for whole-house applications. Its continuous flow technology ensures that you'll have an uninterrupted supply of hot water, which is a significant advantage for larger households or those with high hot water demands. The unit is compact and energy-efficient, featuring a design that doesn't require venting, which makes it a great option if space is limited. The energy savings monitor is a nice addition, allowing you to track your energy costs effectively.

One of the key strengths of the Tempra 24 Plus is its advanced flow control, which helps maintain consistent water temperatures even when multiple outlets are in use. This is particularly beneficial during peak usage times. The digital temperature display and preset memory buttons make it user-friendly, even for individuals who might not be tech-savvy.

However, there are a few drawbacks to consider. The unit requires a minimum electric service of 150 A, which may be a limitation for homes with older electrical systems. Installation might be tricky for DIY enthusiasts, as it typically requires a professional to handle the electric setup. Additionally, while the unit operates quietly, some users might find that the slight reduction in flow during high demand could be a minor inconvenience. The warranty provided, including a 7-Year Leakage and 3-Year Parts Warranty, adds a layer of confidence in its reliability. The Stiebel Eltron Tempra 24 Plus is a well-rounded option for those prioritizing efficiency and continuous hot water, though it's best suited for households ready for potential electrical upgrades.

Rating
9.9
Flow Rate
Energy Efficiency
Size and Installation

Most important from
2120 reviews

Flow Rate
What truly sets this heater apart is its ability to provide a continuous flow of hot water, even with multiple outlets in use.
Energy Efficiency
This tankless water heater's performance has exceeded my expectations in terms of convenience and efficiency.
Size and Installation
The unit is impressively quiet, and its space-saving design is a game-changer.
Temperature Rise
The temperature control is precise, ensuring you get the hot water you desire without any fuss.

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.

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