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10 Best Tankless Hot 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 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
Chosen by1,313
Temperature Rise
Size and Installation

Most important from
166 reviews

Temperature Rise
Impressive performance with no issues post-installation; the temperature adjustment was minimal.
Size and Installation
Installation is straightforward, and the unit is not as heavy as most.

The Rheem RTGH-95DVLN-3 is a robust tankless water heater designed for residential indoor use with natural gas. Its standout feature is the impressive flow rate, ranging from 0.4 to 9.5 gallons per minute (GPM), making it suitable for larger households with higher hot water demands. The energy efficiency is also notable at 0.93, meaning it can help reduce energy bills compared to traditional water heaters.

The unit requires 120 volts for operation and includes an electric ignition, adding convenience and reliability in starting the heater. Temperature settings are flexible, ranging from 100 to 140 degrees Fahrenheit, catering to various preferences and needs, with a default setting of 120F. The size is relatively compact at 17.7 inches wide and 23.7 inches high, which can be a good fit for many installation spaces, though it is somewhat heavy at 59.9 pounds, which might make installation a bit challenging for some users. The integrated digital display is a useful feature for monitoring and adjusting settings easily.

However, the warranty coverage could be better; while the heat exchanger is covered for 15 years, labor is only covered for one year, and parts for five years. Potential buyers should weigh its benefits against the warranty limitations and installation considerations.

Rating
10.0
Chosen by1,313
Temperature Rise
Size and Installation

Most important from
166 reviews

Temperature Rise
Impressive performance with no issues post-installation; the temperature adjustment was minimal.
Size and Installation
Installation is straightforward, and the unit is not as heavy as most.
#2

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

Rating
8.8
Flow Rate (GPM)
Energy Efficiency
Temperature Rise

Most important from
3900 reviews

Flow Rate (GPM)
Consistency is key; as long as you have power, you never run out of hot water, making it perfect for households with high hot water demands.
Energy Efficiency
We are very pleased with the product's efficiency and excellent workmanship.
Temperature Rise
Installation was straightforward, and the unit worked exactly as intended, heating very quickly.
Size and Installation
The compact size is a major plus, fitting easily into small spaces while delivering a continuous hot water supply.

The Rheem RTEX-24 Electric Tankless Water Heater is a solid choice for those seeking an efficient and high-capacity water heating solution. One of its major strengths is its impressive flow rate of up to 5.9 gallons per minute (GPM), which is suitable for serving multiple fixtures simultaneously. Additionally, its 99.8% energy efficiency rating makes it an economical option, as it minimizes energy waste and reduces utility bills.

The electric fuel type ensures ease of installation without the need for gas lines, making it a convenient option for many users. Its compact size (17.63"W x 18.25"H x 3.5"D) and wall-mount capability further enhance its suitability for smaller spaces or areas where floor space is at a premium. The product also boasts a user-friendly digital temperature display and self-modulating power control, which contribute to maintaining consistent and continuous hot water supply on demand.

However, there are some drawbacks to consider. The maximum flow rate may not be sufficient for larger households with high hot water demands during peak usage times. In summary, the Rheem RTEX-24 is an excellent option for small to medium-sized households or professional use, offering high efficiency, ease of installation, and reliable performance within its capacity limits.

Rating
8.8
Flow Rate (GPM)
Energy Efficiency
Temperature Rise

Most important from
3900 reviews

Flow Rate (GPM)
Consistency is key; as long as you have power, you never run out of hot water, making it perfect for households with high hot water demands.
Energy Efficiency
We are very pleased with the product's efficiency and excellent workmanship.
Temperature Rise
Installation was straightforward, and the unit worked exactly as intended, heating very quickly.
Size and Installation
The compact size is a major plus, fitting easily into small spaces while delivering a continuous hot water supply.
#3

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

Rating
7.6
Flow Rate (GPM)
Energy Efficiency
Size and Installation

Most important from
327 reviews

Flow Rate (GPM)
Delivers prompt hot water flow even to bathrooms far from the unit, making daily use seamless and convenient.
Energy Efficiency
Offers excellent energy efficiency that leads to noticeable savings compared to electric water heaters.
Size and Installation
Installation is straightforward and manageable, especially with some plumbing knowledge, and can be a DIY project for those experienced.

The Rinnai RX130iN tankless water heater is a versatile choice for anyone needing a reliable source of hot water without the bulk of a traditional tank. It delivers up to 7.1 gallons per minute, meaning it can comfortably supply hot water to multiple fixtures at once, which is great for larger households. This model runs on natural gas or propane, making it flexible depending on your fuel preference or availability. Its energy efficiency is excellent, with a high UEF rating of 0.97, so it uses fuel very efficiently, helping keep utility costs lower.

The unit is compact, about the size of a small suitcase, and can be installed indoors or outdoors, provided you use the correct venting accessories. This makes it a good fit for various home setups but professional installation is strongly recommended to ensure safety and proper operation. The maximum temperature reaches 140°F, which is sufficient for most household needs. The built-in Smart Sense gas control helps optimize performance and safety, while features like Quick Flush make maintenance easier.

The price and installation complexity might be higher compared to simpler models, and the WiFi control option requires an additional purchase. Although it is energy-efficient, it still requires a gas connection and a 120V power source for controls. If you want a steady supply of hot water, good energy savings, and flexibility in installation with a trusted brand backing, this Rinnai model is worth considering.

Rating
7.6
Flow Rate (GPM)
Energy Efficiency
Size and Installation

Most important from
327 reviews

Flow Rate (GPM)
Delivers prompt hot water flow even to bathrooms far from the unit, making daily use seamless and convenient.
Energy Efficiency
Offers excellent energy efficiency that leads to noticeable savings compared to electric water heaters.
Size and Installation
Installation is straightforward and manageable, especially with some plumbing knowledge, and can be a DIY project for those experienced.

Buying Guide for the Best Tankless Hot Water Heaters

Choosing the right tankless hot water heater can significantly improve your home's energy efficiency and ensure you have a reliable supply of hot water. Unlike traditional water heaters that store hot water in a tank, tankless models heat water on demand, which can save space and reduce energy costs. To find the best fit for your needs, it's important to understand the key specifications and how they relate to your household's requirements.
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 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 energy costs. For example, a unit with an EF of 0.8 is less efficient than one with an EF of 0.95. To pick the right one, look for models with higher efficiency ratings, especially if you are concerned about reducing your energy bills and environmental impact.
Fuel TypeTankless water heaters can be powered by electricity, natural gas, or propane. The fuel type affects installation costs, operating costs, and performance. Electric models are typically easier to install and maintain but may have higher operating costs. Gas models, on the other hand, often provide higher flow rates and are more cost-effective in the long run but require proper ventilation and may have higher upfront installation costs. Choose the fuel type based on your existing infrastructure, availability of fuel sources, and long-term cost considerations.
Temperature RiseTemperature rise refers to the difference between the incoming water temperature and the desired output temperature. This spec is important because it affects the heater's ability to provide hot water in colder climates. For instance, if the incoming water temperature is 50°F and you want it heated to 120°F, the unit needs to handle a 70°F temperature rise. To choose the right model, consider the average temperature of your incoming water and ensure the heater can achieve the desired output temperature, especially during colder months.
Size and InstallationThe physical size of the tankless water heater and its installation requirements are important factors to consider. Tankless units are generally more compact than traditional tanks, but you still need to ensure you have enough space for installation. Additionally, some models may require specific venting or electrical upgrades. To pick the right size, measure the available space and check the installation requirements of the unit. If you have limited space or specific installation constraints, look for models designed for easy installation in tight spaces.
Warranty and SupportThe warranty and support offered by the manufacturer can provide peace of mind and protect your investment. Warranties typically cover parts and labor for a certain period, and longer warranties often indicate higher quality and reliability. To choose the right model, compare the warranty terms and consider the availability of customer support and service centers. Opt for a unit with a comprehensive warranty and good customer support to ensure you can get help if any issues arise.

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