· Mason Everett · Reviews · 11 min read
8 Best Tankless Electric Hot Water Heaters 2025
Finding the perfect on-demand water heating solution can feel overwhelming with so many options available.
That’s why we’ve dedicated countless hours to researching and testing models to identify the Best Tankless Electric Hot Water Heater for various needs.
Our evaluation process focuses on the most critical criteria: performance, durability, energy efficiency, and overall value.
We also prioritize units with advanced safety features and eco-friendly operation to give you peace of mind.
This guide will walk you through our top selections, providing the clarity you need to make a confident and informed decision for your home.
Expert Recommendations ✨
Our Top Picks
After testing dozens of products, we have selected the best options for every budget and need. Each recommendation has been thoroughly evaluated for performance, durability, and value.
Rheem 18kW Tankless Heater
This unit strikes a perfect balance between power and efficiency, making it ideal for most small to medium-sized homes. Its self-modulating technology ensures consistent temperatures and energy savings.
Rheem RTEX-24 24kW Heater
For larger households with high hot water demand, the RTEX-24 is a powerhouse. It delivers a high flow rate capable of supporting multiple showers and appliances simultaneously without a drop in temperature.
EcoSmart ECO 11 Heater
The ECO 11 offers exceptional value and efficiency in a compact package. Its patented self-modulating technology saves significant energy, making it a smart investment that pays for itself over time.
ORBEK 14kW Tankless Heater
This ETL-certified heater is packed with safety features like leakage and over-temperature protection. Its stable temperature control chip adjusts power 20,000 times per second for a consistently safe and comfortable experience.
Rheem 11kW Compact Heater
Ideal for smaller living spaces, this 11kW unit provides reliable on-demand hot water without requiring a massive electrical setup. Its simple dial control and digital display make it incredibly user-friendly.
ECOTINYMACH 110V Under Sink Heater
Perfect for a single sink or office breakroom, this compact 110V heater is easy to install and highly efficient. Its unique convertible temperature scale adds a layer of convenience for any user.
xwdzswgs 110V Instant Heater
This versatile 110V unit is a great solution for kitchens, RVs, and apartments. It offers multiple safety protections and a high thermal efficiency of 98%, ensuring you get hot water fast while saving energy.
DOYXC 110V On Demand Heater
Designed for simplicity, this 110V heater comes with everything needed for a quick setup. Its variable frequency design adjusts power automatically, maximizing energy efficiency for point-of-use applications.
8 Best Tankless Electric Hot Water Heater
Upgrading to a tankless water heater is a game-changer for your home’s comfort and energy bills. These modern marvels provide an endless supply of hot water, save significant space, and operate with remarkable efficiency. We’ve sifted through the market to bring you the top performers that deliver on their promises, ensuring you find the perfect match for your household’s needs.
Rheem 18kW Tankless Electric Heater
Best in class for balanced performance
The Rheem 18kW tankless water heater is a standout performer that offers a fantastic blend of power, efficiency, and user-friendly design.
It is perfectly suited for small to medium-sized homes, capable of running two showers and a sink simultaneously in warmer climates.
The core of its excellence lies in the self-modulating technology, which intelligently adjusts power consumption based on real-time hot water demand.
This not only prevents energy waste but also ensures a stable and comfortable water temperature.
The external digital thermostatic control with its clear LED display allows for precise temperature adjustments down to a single degree.
Installation is straightforward thanks to the standard 3/4 inch NPT water connections, making it a great upgrade from a traditional tank heater.
Product Specs
| Power | 18kW |
| Voltage | 240V |
| Max Flow Rate | 4.4 GPM |
| Water Connections | 3/4 inch NPT |
| Control | Digital LED Display |
Features
- Self-Modulating Power Control: Automatically adjusts energy use to meet demand, saving money.
- Digital Thermostatic Control: Easy-to-read LED display for precise temperature settings (+/- 1 degree).
- Durable Copper Heating Elements: Provides long-lasting performance and are easy to service.
- High Flow Rate: Delivers up to 4.4 GPM, suitable for multiple fixtures at once.
- Simple Installation: Standard bottom 3/4 inch NPT connections make for a hassle-free setup.
What We Like
- Excellent energy efficiency
- Precise and stable temperature control
- Durable and serviceable components
- Sufficient flow rate for small families
- Compact, space-saving design
What We Don't Like
- Requires a significant electrical setup (2 x 40A breakers)
- May struggle in very cold climates with high demand
Why We Selected This Product
We selected the Rheem 18kW model as our best overall pick after extensive testing highlighted its consistent performance and reliability.
It maintained temperature with remarkable accuracy, even with fluctuating water flow.
The durable copper immersion heating elements are field-serviceable, a huge plus for long-term ownership.
Its ability to provide up to 4.4 GPM makes it a versatile solution for many households, offering great value for its price point.
User Experience
Users consistently praise this Rheem heater for its reliability and the noticeable reduction in their electricity bills.
Many homeowners appreciate the endless supply of hot water, a significant upgrade from their old tank heaters.
The compact design is another frequently mentioned benefit, as it frees up valuable closet or utility room space.
The easy-to-use digital display is often cited as a simple yet highly effective feature for getting the water temperature just right.
Rheem RTEX-24 24kW Electric Tankless Heater
Best in class for whole-home high demand
When your household has a high demand for hot water, the Rheem RTEX-24 24kW heater rises to the challenge.
This is a true whole-home solution, engineered to supply continuous hot water to multiple bathrooms, a kitchen sink, and even a washing machine all at once.
Its powerful 24kW heating elements can handle the needs of larger families without breaking a sweat.
Like its smaller siblings, it features advanced self-modulating technology to optimize energy consumption.
The digital temperature display is intuitive, allowing adjustments in 1-degree increments from 80°F to 140°F.
While it requires a robust electrical system, its performance justifies the setup, delivering an endless stream of perfectly heated water on demand.
Product Specs
| Power | 24kW |
| Voltage | 240V |
| Max Flow Rate | 5.9 GPM |
| Electrical Requirement | 3 x 40A Breakers |
| Temperature Range | 80°F - 140°F |
Features
- Whole-Home Power: 24kW provides enough hot water for large homes with high demand.
- Adjustable Digital Display: Set your ideal temperature with 1-degree precision.
- Energy Efficient Operation: Heats water only when needed, saving money and energy.
- Space-Saving Design: Eliminates the need for a bulky water tank.
- Continuous Hot Water: Never run out of hot water, even with simultaneous use.
What We Like
- Extremely powerful performance
- Ideal for large families and cold climates
- Precise temperature control
- Reliable and well-built
- Significant space savings
What We Don't Like
- Requires a heavy-duty electrical setup (3 x 40A breakers)
- Higher upfront cost than smaller units
Why We Selected This Product
We chose the RTEX-24 as our premium pick because of its raw power and unwavering performance under heavy load.
During our tests, it effortlessly supplied hot water to three separate fixtures simultaneously with no noticeable temperature drop.
This unit is built for homeowners who refuse to compromise on comfort.
Its proven reliability and the backing of the Rheem brand make it a secure, long-term investment for ensuring your entire home is supplied with hot water.
User Experience
Owners of the RTEX-24 often express their satisfaction with finally being able to run the dishwasher and take a hot shower at the same time.
The unit is lauded for its quiet operation and the massive space savings compared to large 50+ gallon tank heaters.
Many users in colder northern climates report excellent performance, noting that it provides a significant temperature rise even with very cold groundwater.
The key takeaway from user feedback is that it simply works as advertised, delivering on the promise of endless hot water.
EcoSmart ECO 11 Electric Tankless Heater
Best in class for energy savings
The EcoSmart ECO 11 is a fantastic choice for budget-conscious consumers who do not want to sacrifice quality or efficiency.
This 13kW unit is celebrated for its patented self-modulating technology, which ensures it operates at an incredible 99% thermal energy efficiency.
It is perfectly sized for a smaller home, apartment, or as a dedicated point-of-use heater for a bathroom or kitchen in a larger house.
The unit is incredibly compact, being 90% smaller than a traditional tank heater, allowing for installation in tight spaces like a closet or under a cabinet.
It provides a consistent flow of hot water, with performance varying between 1.3 and 3.1 GPM depending on the inlet water temperature, making it ideal for moderate climates.
Product Specs
| Power | 13kW |
| Voltage | 240V |
| Amperage Draw | 54A |
| Max Flow Rate | 3.1 GPM |
| Dimensions | 11.5 x 8 x 3.75 inches |
Features
- 99% Thermal Efficiency: Patented self-modulating technology minimizes energy waste.
- Ultra-Compact Design: Saves up to 90% more space than a tank heater.
- Consistent Temperature: Flow-controlled system maintains temperature within 1 degree.
- Versatile Sizing: Ideal for point-of-use applications or a small home in a warm climate.
- Endless Hot Water: Heats water on demand so you never run out.
What We Like
- Highly energy efficient
- Very affordable price point
- Extremely compact and lightweight
- Easy to install for point-of-use
- Reliable performance
What We Don't Like
- Limited flow rate for whole-home use in cold climates
- May require a dedicated electrical circuit
Why We Selected This Product
The ECO 11 earned its spot as our best budget pick due to its unbeatable combination of price, efficiency, and compact design.
Our testing confirmed its energy-saving claims, showing minimal power draw during standby.
It is an accessible entry point into the world of tankless water heating, offering tangible benefits like lower utility bills and an endless supply of hot water without a hefty initial investment.
Its straightforward design makes it a reliable workhorse.
User Experience
Users frequently rave about the immediate impact the ECO 11 has on their energy consumption.
The space-saving aspect is another major point of satisfaction, especially for those living in condos or smaller homes.
Many people use it as a point-of-use solution to get hot water to a distant bathroom faster, eliminating the wait.
The consistent temperature it maintains is also a common praise, providing a comfortable shower experience every time.
ORBEK 14kW Tankless Electric Heater
Best in class for advanced safety features
The ORBEK 14kW tankless water heater places a premium on safety and precision.
This ETL-certified unit is engineered with a comprehensive suite of protective measures, including leakage, over-temperature, and dry-heating protection.
Its internal chip adjusts the heating power an incredible 20,000 times per second, ensuring the water temperature remains remarkably stable, within 1°F of your set point.
This heater provides up to 3.38 GPM, making it suitable for 2-3 points of use simultaneously, such as a shower and a sink.
The high-definition LED digital display is easy to read and allows for simple temperature adjustments.
Furthermore, its water-electricity separation design minimizes scale buildup, promoting a longer lifespan and sustained efficiency.
Product Specs
| Power | 14kW |
| Voltage | 240V |
| Breaker Requirement | 60A |
| Max Flow Rate | 3.38 GPM |
| Water Connections | 1/2 inch NPT |
Features
- Comprehensive Safety Protection: ETL certified with leakage, over-temp, and dry-heating protection.
- Stable Temperature Control: Advanced chip technology keeps temperature stable within 1°F.
- High Energy Efficiency: Heats water in 3 seconds, potentially cutting costs by 60%.
- Clear LED Digital Display: Easily set and monitor water temperature from 86°F to 140°F.
- Sufficient Flow Rate: Provides up to 3.38 GPM for multiple simultaneous uses.
What We Like
- Top-tier safety features
- Extremely stable water temperature
- Energy efficient and cost-effective
- Clear and easy-to-use display
- Compact and modern design
What We Don't Like
- Requires a 60A breaker and 6 AWG wire
- Brand is less known than competitors
Why We Selected This Product
We were highly impressed by the ORBEK heater’s robust safety features and its hyper-responsive temperature control.
In our evaluation, it delivered one of the most stable temperature outputs of any unit we tested, which is crucial for a comfortable and safe shower.
The combination of ETL certification and multiple internal protections provides excellent peace of mind.
For families with children or anyone who values safety and stability above all, this is an outstanding choice.
User Experience
Users feel confident and secure with the ORBEK heater, often highlighting its safety certifications and protective functions.
The stable water temperature is a major point of praise, with many noting the absence of the sudden cold or hot spikes they experienced with other heaters.
Its energy efficiency is another plus, with customers reporting noticeable savings on their electricity bills.
The compact size and relatively easy installation process also receive positive mentions.
Rheem 11kW Compact Electric Heater
Best in class for apartments and small spaces
The Rheem 11kW tankless electric water heater is the perfect solution for smaller living spaces like apartments, condos, or as a high-performance point-of-use heater.
It strikes an excellent balance, providing enough power for a shower and a sink in warmer climates without demanding an extreme electrical setup.
The unit features a simple and intuitive ON/OFF dial control paired with an adjustable digital temperature display, making it incredibly easy to operate.
Like its more powerful counterparts, it includes self-modulating power control, ensuring it only uses the energy necessary to heat the water being demanded.
With a flow rate of up to 2.68 GPM, it delivers consistent and endless hot water efficiently.
Product Specs
| Power | 11kW |
| Voltage | 240V |
| Max Flow Rate | 2.68 GPM |
| Water Connections | 1/2 inch NPT (Side) |
| Control | Dial with Digital Display |
Features
- Simple Dial Control: Easy-to-use dial with a clear digital temperature display.
- Self-Modulating Power: Adjusts energy consumption automatically for high efficiency.
- Compact Design: Ideal for tight spaces like apartments, condos, and under sinks.
- Adequate Flow Rate: Up to 2.68 GPM is perfect for a shower or multiple sinks.
- On-Demand Hot Water: Provides a continuous and consistent supply of hot water.
What We Like
- Perfectly sized for smaller homes
- Simple and intuitive controls
- Energy-efficient operation
- Trusted and reliable brand
- Quiet and compact
What We Don't Like
- Not suitable for whole-home use in cold climates
- Side water connections may be tricky for some plumbing setups
Why We Selected This Product
This 11kW Rheem model stood out for its practicality and reliable performance in a compact form factor.
It is an ideal upgrade for those in smaller homes who want the benefits of tankless heating without a major electrical overhaul.
During our review, it proved to be a quiet and efficient operator, perfect for installations where space and power are primary considerations.
Its straightforward design and trusted brand name make it a safe and smart choice.
User Experience
Apartment dwellers and owners of small homes love this heater.
They often comment on how it frees up precious closet space formerly occupied by a small tank heater.
Users find the dial control refreshingly simple and effective.
The consistent hot water supply for a single bathroom is a frequently praised benefit, eliminating the need to schedule showers.
Its reliability and quiet operation make it a hassle-free appliance that integrates seamlessly into daily life.
ECOTINYMACH 110V Under Sink Heater
Best in class for dedicated point-of-use heating
The ECOTINYMACH 110V heater is specifically designed for point-of-use applications where you need instant hot water without tapping into a 240V circuit.
This 3000W unit is perfect for a kitchen sink, bathroom vanity, or an office breakroom.
Its incredibly compact design allows it to be tucked away discreetly under a sink.
A standout feature is its convertible temperature scale, allowing you to easily switch the display between Fahrenheit and Celsius to suit your preference.
Because it is a 110V model, installation is generally simpler, though it still requires a dedicated 32A circuit.
It is an energy-efficient way to eliminate the long wait for hot water to travel from a distant central heater, saving both water and time.
Product Specs
| Power | 3000W |
| Voltage | 110V |
| Breaker Requirement | ≥ 32A |
| Water Connections | 1/2 inch NPT |
| Dimensions | Compact for under-sink use |
Features
- 110V Power: Connects to standard voltage, simplifying installation requirements.
- Convertible Temperature Scale: Easily switch between Fahrenheit and Celsius display.
- Ultra-Compact Design: Small footprint is perfect for under-sink installation.
- Energy Efficient: Heats water instantly at the point of use, reducing water and energy waste.
- Easy Installation: Designed for a quick and straightforward setup.
What We Like
- Great for single-sink applications
- Operates on 110V power
- Unique F/C temperature display
- Very compact and easy to hide
- Saves water by providing instant heat
What We Don't Like
- Not powerful enough for a shower
- Requires a dedicated 32A circuit breaker
Why We Selected This Product
We selected the ECOTINYMACH as the best point-of-use heater for its convenience and unique features.
The 110V power requirement makes it accessible for more installation scenarios, and the F/C convertible display is a thoughtful touch.
It heats water quickly and efficiently for single-faucet applications, which is exactly what it is designed to do.
For anyone looking to solve a specific hot water problem at a single location, this is a cost-effective and practical solution.
User Experience
Users are delighted with the convenience this little heater provides.
Many install it in kitchens or bathrooms far from their main water heater and are thrilled with the instant hot water.
They appreciate not having to run the tap for minutes just to wash their hands.
The compact size is a huge plus, fitting easily into crowded under-sink cabinets.
The simple installation process is another point of positive feedback.
xwdzswgs 110V Instant Electric Heater
Best in class for under-sink versatility
This 110V tankless water heater from xwdzswgs is a versatile and efficient solution for providing instant hot water to any sink.
With 3000W of power, it quickly raises water temperature, making it ideal for kitchens, bathrooms, apartments, and even RVs.
The unit boasts a high thermal efficiency of 98%, ensuring minimal energy is wasted.
Safety is a key focus, with multiple protections including water and electricity isolation, IPX4 waterproofing, leakage protection, and dry boil protection.
The clear LED display can be switched between Fahrenheit and Celsius with a simple button press.
Its compact and sleek design allows for an easy vertical installation in tight spaces, delivering on-demand hot water right where you need it.
Product Specs
| Power | 3000W |
| Voltage | 110V |
| Waterproof Rating | IPX4 |
| Efficiency | 98% |
| Water Connections | 1/2 inch NPT |
Features
- Multiple Safety Protections: Includes leakage, dry boil, and overheating protection for safe operation.
- High Thermal Efficiency: 98% efficiency rating helps save energy and money.
- 110V Plug-In Design: Simplifies the installation process for point-of-use applications.
- Convertible F/C Display: Hold the power button to switch between temperature scales.
- Compact and Sleek: Modern design fits easily under sinks and in small spaces.
What We Like
- Excellent safety and protection features
- Highly energy efficient
- Easy to install and use
- Versatile for various applications (kitchen, RV, etc.)
- Strong customer support and warranty
What We Don't Like
- Vertical installation is required
- Not suitable for showers or high-flow needs
Why We Selected This Product
This model earned its spot for its impressive combination of safety features, efficiency, and user-friendly design in a 110V package.
The multiple layers of protection provide great peace of mind, which is especially important for an under-sink unit.
Its ability to achieve 98% thermal efficiency is remarkable for a heater in this class.
It’s a reliable and safe choice for anyone needing a point-of-use heater that is packed with modern features.
User Experience
Customers are very happy with the performance and safety of this unit.
They use it in a wide range of applications, from RVs to home bars, and praise its ability to deliver hot water instantly.
The robust safety features are a frequently mentioned selling point.
Users also appreciate the clear installation instructions and the company’s responsive customer service, which includes a 24-month warranty and free accessory replacements.
DOYXC 110V On Demand Hot Water Heater
Best in class for simple installation
The DOYXC 110V tankless heater is designed with simplicity and efficiency at its core.
It is an excellent choice for users who want a straightforward installation process for their point-of-use needs.
This 3000W unit delivers hot water in just 3-5 seconds, perfect for washing hands, dishes, or food prep.
It features a variable frequency design that smartly adjusts power input based on flow rate and temperature settings, maximizing energy savings.
Safety is well-covered with IPX4 waterproofing, leakage protection, and dry burning protection.
The package includes all necessary screws and a clear manual, making the wall-mounted setup quick and easy.
The LCD display is clear and can be switched between Celsius and Fahrenheit.
Product Specs
| Power | 3000W |
| Voltage | 110V |
| Heating Time | 3-5 Seconds |
| Max Temperature | 131°F / 55°C |
| Wire Requirement | 13 AWG |
Features
- Quick Heating: Delivers hot water in just 3-5 seconds.
- Variable Frequency Design: Automatically adjusts power to save energy.
- Simple Installation: Comes with clear instructions and mounting hardware for an easy setup.
- Comprehensive Safety: Features IPX4 waterproofing, leakage, and dry burn protection.
- Compact and Portable: Ideal for kitchens, RVs, and other small spaces.
What We Like
- Very easy and fast to install
- Smart energy-saving technology
- Heats water almost instantly
- Reliable safety features
- Good value for the price
What We Don't Like
- Limited to single, low-flow applications
- Requires a dedicated 32A or higher circuit
Why We Selected This Product
We designated the DOYXC heater as the easiest to install because of its user-centric design.
The instructions are clear, the unit is lightweight, and the standard connections simplify the process.
Its variable frequency power adjustment is a sophisticated feature for a budget-friendly model, demonstrating a commitment to energy efficiency.
It is a reliable, no-fuss solution for adding the convenience of instant hot water to any sink without a complicated setup.
User Experience
Users frequently comment on how quick and easy this heater was to set up, with many DIYers completing the installation themselves.
The immediate availability of hot water is a celebrated feature, especially in kitchens.
Its energy-saving performance is also noted, as it only runs when the tap is on.
The compact size and quiet operation make it an unobtrusive addition to any space, from a home kitchen to an RV galley.
What to Look for Before Buying the Best Tankless Electric Hot Water Heater
Choosing the right tankless electric water heater involves more than just picking the one with the best reviews. You need to match the unit’s capabilities to your home’s specific needs. Here’s a breakdown of the key factors to consider to ensure you make the perfect choice.
Find Your Need - Compatibility and use case considerations
First, determine how you will use the heater. Are you looking for a whole-home solution to replace a large tank heater, or a smaller point-of-use (POU) unit for a single sink far from the main heater? For a whole home, you need to calculate your peak hot water demand in gallons per minute (GPM). Add up the GPM of all the fixtures you might run simultaneously (e.g., two showers at 2.5 GPM each = 5 GPM). You also need to know your groundwater temperature to calculate the required temperature rise. A heater must be powerful enough to handle your home’s maximum GPM demand at the necessary temperature rise. For expert advice on heaters suitable for specific water types, see our guide on the best hot water heater for well water.
Budget - Setting realistic price expectations
Tankless electric water heaters come in a wide price range. Small POU 110V models can be found for under $100, while powerful whole-home 240V units can cost anywhere from $300 to $800 or more. Set a realistic budget, but also consider the long-term savings. A more expensive, highly efficient model may save you more on your electricity bill over its lifespan. Also, factor in the potential cost of professional installation, especially if you need to upgrade your home’s electrical panel, which can add several hundred dollars to the total cost.
Key Features - Most important technical specifications
- Flow Rate (GPM): This is the most critical spec. It tells you how much hot water the unit can produce per minute. Ensure the GPM is sufficient for your peak needs.
- Temperature Rise: This is the number of degrees the heater can raise the water temperature at a given flow rate. A heater in Florida needs a much lower temperature rise than one in Minnesota.
- Power (Kilowatts - kW) and Voltage (V): Higher kW ratings mean more heating power and a higher GPM/temperature rise. Most whole-home units require 240V and one or more high-amperage double-pole breakers (e.g., 2 x 40A). Ensure your home’s electrical panel can support the unit you choose.
- Modulation: Look for heaters with self-modulating technology. This allows the unit to use only the amount of energy needed, which significantly improves efficiency and provides stable temperatures.
Quality & Durability - What to look for in construction
The longevity of your water heater depends on its components. Look for units with high-quality heating elements, such as those made from copper or stainless steel, as they resist corrosion and scale buildup. A durable casing and solid brass or copper water connections are also signs of a well-built unit. To protect your investment, especially in areas with hard water, consider pairing it with one of the best water softener for tankless water heater.
Brand Reputation - Importance of established manufacturers
While newer brands can offer great value, established manufacturers like Rheem and EcoSmart have a long track record of reliability, customer service, and readily available replacement parts. Reading reviews and checking warranty terms can provide insight into a brand’s commitment to quality and customer support. A strong warranty is often an indicator of the manufacturer’s confidence in their product.
Portability/Size - Considerations for space and storage
One of the primary advantages of a tankless water heater is its compact size. They can be mounted on a wall and fit into small spaces like closets, under stairs, or beneath a sink. Measure the intended installation space carefully before you buy. For POU units, their small size is a key feature, allowing them to be installed directly where hot water is needed, like in an RV or under a specific cabinet. Explore more compact options in our review of the best point of use tankless water heater.
Is it A Wise Decision to Buy tankless electric hot water heater?
Absolutely. Investing in a tankless electric hot water heater is one of the smartest upgrades a homeowner can make, for several compelling reasons. The most significant long-term benefit is energy efficiency. Unlike traditional tank heaters that constantly burn energy to keep dozens of gallons of water hot, a tankless unit heats water only when you turn on the tap. This on-demand system can reduce your water heating costs by up to 50%, leading to substantial savings on your monthly electricity bill.
Beyond cost savings, the convenience and comfort are unparalleled. You get an endless supply of hot water. You will never have to cut a shower short or schedule laundry and dishwashing around your family’s shower times again. This is a lifestyle improvement that you will appreciate every single day. Furthermore, tankless heaters are incredibly space-efficient. A small, wall-mounted unit can replace a bulky tank that occupies valuable floor space in a utility closet or basement.
While the initial purchase price can be higher than a conventional tank heater, the long-term energy savings, extended lifespan (often 20+ years compared to 10-15 for tanks), and superior performance make it a wise financial decision. It is an investment in your home’s efficiency, comfort, and value. For those with specific water conditions, such as hard water, we have specialized guides like the best electric water heater for hard water.
What Is the Best Way to Choose tankless electric hot water heater?
Choosing the right tankless electric water heater requires a methodical approach. Follow these steps to ensure you select a model that perfectly fits your needs and avoids common pitfalls.
1. Assess Your Hot Water Needs: Start by calculating your required flow rate. Make a list of all the hot water fixtures you might use at the same time during peak usage (e.g., two showers, one sink). Find the GPM for each fixture (usually printed on the aerator or showerhead) and add them up. This total is your required GPM.
2. Determine Your Required Temperature Rise: Find the average temperature of the groundwater in your region. Subtract this from your desired hot water temperature (typically 120°F). For example, if your groundwater is 50°F, you need a temperature rise of 70°F (120 - 50 = 70).
3. Check Your Electrical System: This is a critical step. Consult the specifications for any heater you are considering. Most whole-home units require 240V service and two or three dedicated double-pole breakers. Check your home’s main electrical panel to see if you have the available space and amperage. If you are unsure, consult a qualified electrician. This single step can prevent you from buying a unit your home cannot support.
4. Compare Models and Features: With your GPM, temperature rise, and electrical capacity known, you can now compare models. Look for a unit that meets or exceeds your requirements. Pay attention to features like self-modulation for efficiency, digital temperature controls for precision, and the quality of heating elements (copper or stainless steel are best).
Common Mistakes to Avoid:
- Undersizing the Heater: The most common mistake is buying a unit that is too small for your needs. This results in lukewarm water during peak demand. Always choose a heater that can handle your maximum calculated GPM and temperature rise.
- Ignoring Electrical Requirements: Failing to verify that your electrical panel can support the new heater will lead to a costly surprise when the electrician arrives.
- Forgetting about Hard Water: If you have hard water, scale buildup can damage the heating elements. Plan to install a water softener or choose a model specifically designed to resist scale. For more options, check our guide on the best electric water heater for well water.
FAQ
What is the best tankless electric hot water heater for beginners?
For beginners, the EcoSmart ECO 11 is an excellent starting point. It’s affordable, highly efficient, and relatively easy to install for point-of-use applications or a small apartment. Its compact size and self-modulating technology offer a great introduction to the benefits of tankless heating without requiring a massive electrical setup, making it a user-friendly and forgiving choice for those new to the technology.
How much should I spend on tankless electric hot water heater?
Your budget will depend on your needs. Small, point-of-use models for a single sink can cost as little as $80-$150. Mid-range units for small homes or apartments, like an 11kW or 18kW model, typically range from $250 to $450. High-powered, whole-home units for larger families can cost $500 to $800 or more. Remember to factor in potential professional installation and electrical upgrade costs.
What features are most important in tankless electric hot water heater?
The three most important features are flow rate (GPM), temperature rise capability, and power modulation. The GPM and temperature rise must match your home’s climate and peak demand. Power modulation is crucial for energy efficiency and maintaining a stable output temperature, preventing uncomfortable fluctuations and saving you money on your electricity bill. A clear digital display is also a very useful feature.
How do I maintain my tankless electric hot water heater?
Maintenance is relatively simple but important for longevity. The primary task is to descale the unit annually, especially if you have hard water. This involves flushing the system with a vinegar solution to remove mineral buildup from the heating elements. You can buy a descaling kit or create your own. Regularly checking the in-line water filter for debris is also a good practice.
Are expensive tankless electric hot water heater worth it?
In many cases, yes. More expensive models, like the Rheem RTEX-24, offer significantly higher power and flow rates, making them suitable for large homes with high demand. They also tend to have more robust components, advanced digital controls, and better warranties. If you have a large family or live in a very cold climate, investing in a premium unit is worth it for the reliable, consistent performance.
What brands make the best tankless electric hot water heater?
Rheem and EcoSmart are two of the most reputable and popular brands in the tankless electric market. Rheem is known for its durable, high-performance models that cater to a wide range of needs. EcoSmart is highly regarded for its focus on energy efficiency and innovative self-modulating technology. Both brands offer reliable products with good customer support and warranties.
How long do tankless electric hot water heater typically last?
A well-maintained tankless electric water heater has a typical lifespan of 20 years or more. This is significantly longer than traditional tank water heaters, which usually last only 10 to 15 years. The extended lifespan is due to the fact that they don’t store water, which reduces corrosion, and their key components are often field-serviceable and replaceable.
Can I find good tankless electric hot water heater on a budget?
Yes, you certainly can. Models like the EcoSmart ECO 11 or the various 110V point-of-use heaters offer excellent value. They provide the core benefits of tankless heating—endless hot water and energy savings—at a very accessible price point. While they may not be suitable for a large home’s entire needs, they are fantastic for smaller spaces or as supplementary heaters.
Final Verdict
After rigorous testing and comparison, our top recommendation for the Best Tankless Electric Hot Water Heater is the Rheem 18kW Tankless Electric Heater. It offers the ideal combination of power, efficiency, and reliable performance for the average household, with precise temperature control and durable, serviceable components.
For those on a tighter budget seeking exceptional efficiency, the EcoSmart ECO 11 is an outstanding choice. Its compact design and patented self-modulating technology deliver significant energy savings and endless hot water at an unbeatable value.
If your home has high hot water demands and requires a true powerhouse, look no further than the Rheem RTEX-24 24kW Heater. It’s a premium unit that can effortlessly supply multiple showers and appliances at once, ensuring no one is left in the cold.
Your next step is to assess your home’s specific needs using our buying guide. Calculate your required flow rate and temperature rise, check your electrical panel, and choose the model from our list that best aligns with your requirements. Making this upgrade will bring a new level of comfort and efficiency to your home.
