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10 Best Tankless Water Heaters 2026 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

Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Rating
10.0
Chosen by1,217
Flow Rate
Energy Efficiency
Size and Installation

Most important from
3873 reviews

Flow Rate
The unit provides endless hot water, even for a household with high demands like three boys.
Energy Efficiency
The reduced electricity bills were a noticeable benefit.
Size and Installation
Installation was straightforward and the unit worked exactly as intended. The compact size and quick heating were impressive.

The Rheem RTEX-24 24kW 240V Electric Tankless Water Heater offers a robust solution for continuous hot water supply with its impressive flow rate of up to 5.9 gallons per minute, making it suitable for households with moderate to high hot water demands. One of its standout features is the 99.8% energy efficiency, which helps in reducing energy costs and promoting eco-friendliness. The electric fuel type simplifies installation and maintenance compared to gas models, although it does require a 240V electrical connection, which some homes may need to upgrade to accommodate.

The compact dimensions (17.63”W x 18.25”H x 3.5”D) and wall-mount design make it space-efficient and ideal for small utility areas, while the digital temperature display and ON/OFF dial control provide ease of use and precise temperature adjustments. Additionally, the self-modulating power control enhances efficiency by only using the necessary amount of power based on the water flow rate.

However, the temperature rise might be limited during peak usage in colder climates, potentially requiring additional units for larger homes. Potential buyers should consider the installation requirements and whether their household electrical setup can support the unit. Those looking for a reliable, energy-efficient, and continuous hot water supply will find the Rheem RTEX-24 a compelling option, especially in moderate climates and homes with appropriate electrical infrastructure.

Rating
10.0
Chosen by1,217
Flow Rate
Energy Efficiency
Size and Installation

Most important from
3873 reviews

Flow Rate
The unit provides endless hot water, even for a household with high demands like three boys.
Energy Efficiency
The reduced electricity bills were a noticeable benefit.
Size and Installation
Installation was straightforward and the unit worked exactly as intended. The compact size and quick heating were impressive.
#2

Rheem 18kW 240V Tankless Electric Water Heater, Gray

Rating
7.9
Size and Installation
Temperature Rise

Most important from
3873 reviews

Size and Installation
Installed in a tiny house and works wonderfully.
Temperature Rise
Biggest acclimatization is that it'll get warmer before it gets hot in the shower. You need to either let it run longer to get to the final temp or adjust as you're showering.

The Rheem 18kW 240V Tankless Electric Water Heater is a compelling option for those looking for an efficient, easy-to-install solution for their hot water needs. One of its standout features is the external digital thermostatic control with an LED display, which offers precise temperature control with +/- 1 degree accuracy. This makes it user-friendly and ensures you always get the perfect water temperature.

Its advanced self-modulation technology is another highlight, as it adjusts power usage based on your hot water demand, contributing to energy efficiency and potentially reducing your energy bills over time. The unit's flow rate is up to 4.4 gallons per minute (GPM), which should be sufficient for small to medium households but might not meet the demands of larger families with high simultaneous water usage.

The heater uses durable copper immersion heating elements that are field-serviceable, enhancing its longevity and ease of maintenance. Installation is straightforward with bottom 3/4 inch NPT water connections and threaded design, making it simple to replace existing water heaters. The compact size (14.5 inches wide and 18.25 inches high) allows it to fit in tight spaces, adding to its versatility. However, as an electric unit, it may not be as powerful as gas models in terms of temperature rise, especially in very cold climates.

Rating
7.9
Size and Installation
Temperature Rise

Most important from
3873 reviews

Size and Installation
Installed in a tiny house and works wonderfully.
Temperature Rise
Biggest acclimatization is that it'll get warmer before it gets hot in the shower. You need to either let it run longer to get to the final temp or adjust as you're showering.
#3

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

Rating
7.9
Flow Rate
Size and Installation
Temperature Rise

Most important from
165 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
7.9
Flow Rate
Size and Installation
Temperature Rise

Most important from
165 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.

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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