Thinking about ditching that old, clunky hot water heater for something more modern and efficient? You're not alone. The idea of a Best Tankless Electric Hot Water Heater is super appealing because it means endless hot water and potential savings on your energy bill.
After diving deep into how these systems work and what real users are saying, I can confidently say that finding the right one makes a huge difference. For many homes, the Rheem 18kW stands out. We'll break down some of the top contenders below.
Comparison Chart of Best Tankless Electric Hot Water Heater
List of Top 10 Best Best Tankless Electric Hot Water Heater
When you're looking for a tankless electric water heater, it's not just about the power rating; you've got to consider flow rate, your home's electrical capacity, and how many hot water outlets you'll be using simultaneously. We've sifted through dozens of options, focusing on reliable brands and features that bring real value.
Below are the list of products:
1. Rheem 18kW 240V Tankless Electric Water
1. Rheem 18kW 240V Tankless Electric Water
I picked the Rheem 18kW because it strikes a fantastic balance between heating power and efficiency for most medium-to-large homes. It’s designed to handle multiple hot water demands at once without a significant drop in temperature. This unit is a solid performer that lives up to its reputation.
Why I picked it
This Rheem unit consistently delivers on its promise of providing hot water on demand for multiple fixtures. Our research indicates that its 18kW power input, paired with a flow rate of up to 4.4 GPM at a 40°F rise, makes it ideal for households with two or three simultaneous hot water needs. It's also praised for its compact size, making installation simpler in tight spaces.
Key specs
- Power Input: 18kW
- Voltage: 240V
- Max Flow Rate: 4.4 GPM (at 40°F temperature rise)
- Temperature Range: 80-140°F
- Dimensions: 14.75 x 12.75 x 3.5 inches
- Weight: 13 lbs
Real-world experience
Users report being able to run a shower and the kitchen sink concurrently without experiencing lukewarm water, which is a common pain point with smaller units. Its digital display allows for easy temperature adjustments, and its durable construction suggests it's built to last.
Trade-offs
The 18kW model requires a substantial electrical circuit, typically a dedicated 90-amp breaker, which might necessitate an electrical panel upgrade for some homes. Installation of such a high-amperage unit is best left to a qualified electrician.
2. EcoSmart ECO 11 Electric Tankless Water
2. EcoSmart ECO 11 Electric Tankless Water
The EcoSmart ECO 11 is a fantastic option if you're looking for a versatile unit that can handle a good amount of hot water demand without being overly power-hungry. It's particularly well-suited for smaller homes or for point-of-use applications where you need hot water in a specific location, like a detached garage or a guest bathroom.
Why I picked it
The ECO 11 offers excellent self-modulating technology, meaning it adjusts its power output based on the flow rate and incoming water temperature. This smart feature ensures you get just the right amount of heat without wasting energy. Aggregated user feedback highlights its effectiveness for single-bathroom homes or for supplying a specific appliance.
Key specs
- Power Input: 13kW
- Voltage: 240V
- Max Flow Rate: 1.5 GPM (at 60°F temperature rise) to 3 GPM (at 30°F temperature rise)
- Temperature Range: 65-140°F
- Dimensions: 17.25 x 8.13 x 3.13 inches
- Weight: 7.5 lbs
Real-world experience
Many reviewers mention successfully using this unit to power a shower and a sink simultaneously in a smaller apartment, reporting consistent hot water flow. Its compact and lightweight design is frequently cited as a major advantage for installation in crawl spaces or tight utility closets. The patented self-modulating technology is a key selling point, praised for its energy efficiency.
Trade-offs
While capable, the ECO 11’s maximum flow rate at a significant temperature rise might not be enough for larger homes with multiple high-demand showers or appliances running at the same time. If you have a high demand for hot water, you might need to consider a higher kW model.
3. Rheem RTEX-24 24kW 240V Electric Tankless
3. Rheem RTEX-24 24kW 240V Electric Tankless
For those looking for robust heating power without breaking the bank, the Rheem RTEX-24 is a standout. This unit offers a higher wattage than the previous Rheem model, delivering more hot water for larger households or homes with higher demand. It’s a great value proposition for powerful performance.
Why I picked it
This 24kW model offers a significant boost in heating capacity, allowing for a higher flow rate of up to 4.8 GPM at a standard 40°F rise. This makes it suitable for whole-house applications, including homes with multiple bathrooms and high-demand fixtures. Verified buyer feedback consistently mentions its reliability and strong performance for its price point.
Key specs
- Power Input: 24kW
- Voltage: 240V
- Max Flow Rate: 4.8 GPM (at 40°F temperature rise)
- Temperature Range: 80-140°F
- Dimensions: 17.5 x 10.6 x 3.75 inches
- Weight: 14.5 lbs
Real-world experience
Many homeowners have reported that this unit easily keeps up with simultaneous use of the dishwasher, washing machine, and showers, something smaller units struggle with. Its digital thermostat is a plus, allowing for precise temperature control. Installation is generally straightforward, assuming adequate electrical capacity is available.
Trade-offs
Like the previous Rheem, this 24kW unit demands a robust electrical connection, typically requiring a 100-amp breaker. Also, while it offers great value, some premium models might have more advanced smart features or slightly better energy efficiency.
4. Electrolux 14kW Tankless Water Heater Electric
4. Electrolux 14kW Tankless Water Heater Electric
Electrolux brings its reputation for quality to the tankless water heater market with this 14kW model. What sets this unit apart is its smart functionality, including WiFi connectivity and Alexa compatibility, allowing for convenient remote control and monitoring. It's a great choice if you're interested in home automation and precise control over your hot water.
Why I picked it
The inclusion of WiFi and Alexa compatibility is a significant draw for tech-savvy homeowners. This model provides a maximum flow rate of up to 3.4 GPM at a 40°F rise, making it suitable for single-family homes with moderate hot water needs. Its ETL certification assures that it meets safety and performance standards.
Key specs
- Power Input: 14kW
- Voltage: 240V
- Max Flow Rate: 3.4 GPM (at 40°F temperature rise)
- Temperature Range: 80-140°F
- Dimensions: 14 x 9.8 x 3.5 inches
- Weight: 10.5 lbs
Real-world experience
Users appreciate the convenience of adjusting settings via a smartphone app or voice commands, fitting seamlessly into a smart home ecosystem. The built-in scale inhibitor is a nice touch, potentially extending the unit's lifespan in areas with hard water. It’s noted for its relatively quiet operation.
Trade-offs
While the smart features are a big plus, they also mean a more complex setup and a higher price point compared to basic models. The 14kW power rating is adequate for many, but for very high-demand households, a more powerful unit might be necessary.
5. Rheem 11kW 240V Tankless Electric Water
5. Rheem 11kW 240V Tankless Electric Water
This Rheem 11kW model is a solid choice for smaller homes, apartments, or situations where hot water is needed for specific purposes like a single bathroom or a small kitchenette. It offers the reliability Rheem is known for in a more compact and less power-intensive package.
Why I picked it
This unit has a power output of 11kW, delivering a flow rate of up to 2.1 GPM at a 40°F temperature rise. Reviews from verified buyers often highlight its suitability for providing hot water for a single shower, sink, or for RVs and small cabins. Its energy efficiency at this power level is also a plus.
Key specs
- Power Input: 11kW
- Voltage: 240V
- Max Flow Rate: 2.1 GPM (at 40°F temperature rise)
- Temperature Range: 80-140°F
- Dimensions: 12.2 x 9.6 x 3.6 inches
- Weight: 8.5 lbs
Real-world experience
Users find this model to be a significant upgrade over traditional tank heaters for smaller applications, offering on-demand convenience. It's frequently installed in situations where space is limited, and the electrical requirements are more manageable than higher-wattage models, often needing a 40-amp breaker.
Trade-offs
The 11kW capacity means it's not designed to handle simultaneous use of multiple high-demand fixtures. If you’re looking to supply hot water to an entire house with multiple bathrooms, this unit will likely be insufficient.
6. Tankless Water Heater Electric
6. Tankless Water Heater Electric
This 3000W electric tankless water heater is designed for point-of-use applications with its 110V input. It’s perfect for scenarios where you only need a small amount of hot water for a sink, such as in a kitchen, bathroom, or a small workspace. Its compact size and lower power requirement make it incredibly versatile.
Why I picked it
This unit's 3000W power rating at 110V is its defining feature, making it incredibly easy to install in many existing setups without requiring major electrical upgrades. User reviews frequently mention its effectiveness for single-sink applications, providing just enough hot water for tasks like washing dishes or hands. The digital display is a nice touch for monitoring temperature.
Key specs
- Power Input: 3000W (3kW)
- Voltage: 110V
- Max Flow Rate: 1.0 GPM (at 40°F temperature rise)
- Temperature Range: 86-131°F
- Dimensions: 7.87 x 5.12 x 2.56 inches
- Weight: 4.2 lbs
Real-world experience
Many buyers have found this perfect for use in workshops, RVs, or even as a supplement to a main water heater for a specific distant faucet. Its small footprint means it can be mounted almost anywhere, and the 110V requirement means it can often plug into a standard outlet.
Trade-offs
The very low power output (3kW) significantly limits its capacity. It's not suitable for showers or situations where a continuous high flow of hot water is needed. It will struggle to provide adequate hot water for more than one low-demand fixture at a time.
7. 14kW Tankless Water Heater Electric
7. 14kW Tankless Water Heater Electric
This SIVUATEK 14kW unit offers a good balance of heating power and a reasonable flow rate, making it a versatile option for many homes. It's ETL certified, which means it has met rigorous safety and performance standards, giving you peace of mind.
Why I picked it
With 14kW of power and a reported flow rate of up to 3.4 GPM at a 40°F temperature rise, this unit is designed for simultaneous use at two points of use. The self-modulating feature helps optimize energy consumption. Verified buyer reviews often point to its compact design, making it an easy fit for various installation locations.
Key specs
- Power Input: 14kW
- Voltage: 240V
- Max Flow Rate: 3.4 GPM (at 40°F temperature rise)
- Temperature Range: 86-131°F
- Dimensions: 14.2 x 10.2 x 3.9 inches
- Weight: 10.8 lbs
Real-world experience
Users appreciate that this unit can supply hot water to both a kitchen sink and a nearby bathroom simultaneously, which is a significant improvement for many households. Its compact dimensions are frequently mentioned as a benefit, simplifying installation especially in tight spaces. The ETL certification is a reassurance of its safety.
Trade-offs
While it can handle two points of use, if those points of use have very high demand (like two simultaneous showers), it might struggle to maintain temperature. Also, like many units in this power class, it requires a dedicated 60-amp circuit, which may necessitate professional electrical work.
8. Electric Tankless Water Heater WINTEMP 27kW
8. Electric Tankless Water Heater WINTEMP 27kW
The WINTEMP 27kW unit is built for homes that need a serious amount of hot water. With its high 27kW power input and WiFi control, it's designed to provide an endless supply for larger households with multiple bathrooms and appliances.
Why I picked it
This WINTEMP unit boasts a powerful 27kW heating element, delivering a substantial flow rate of up to 6.3 GPM at a 40°F rise, making it suitable for larger homes or demanding commercial applications. The WiFi control adds a layer of modern convenience, allowing users to manage temperature settings remotely. Its ETL certification further assures buyers of its quality and safety.
Key specs
- Power Input: 27kW
- Voltage: 240V
- Max Flow Rate: 6.3 GPM (at 40°F temperature rise)
- Temperature Range: 86-131°F
- Dimensions: 18.3 x 12.6 x 4.7 inches
- Weight: 13.5 lbs
Real-world experience
Customers often choose this unit to replace undersized tank heaters or older tankless models that couldn't keep up with their household's demands. The ability to integrate with WiFi is a big plus for those who enjoy smart home features, offering easy access to temperature settings and troubleshooting. It’s noted for its consistent hot water delivery, even during peak usage.
Trade-offs
The 27kW power requirement means this unit needs a very strong electrical connection, typically a dedicated 125-amp breaker. This could lead to significant electrical upgrades if your home's panel isn't already equipped for such a load.
9. Electric Tankless Water Heater SIVUATEK 14kW
9. Electric Tankless Water Heater SIVUATEK 14kW
This SIVUATEK 14kW electric tankless water heater is designed to provide endless hot water for whole-house applications. It's ETL certified and features a self-modulating design for efficiency and consistent temperature output.
Why I picked it
This 14kW unit offers a flow rate of up to 3.4 GPM at a 40°F rise, making it quite capable of handling multiple points of use simultaneously for many households. Its compact form factor is highlighted by many reviewers as a significant benefit, simplifying installation in areas with limited space. The ETL certification indicates it meets safety standards required in North America.
Key specs
- Power Input: 14kW
- Voltage: 240V
- Max Flow Rate: 3.4 GPM (at 40°F temperature rise)
- Temperature Range: 86-131°F
- Dimensions: 14.2 x 10.2 x 3.9 inches
- Weight: 10.8 lbs
Real-world experience
Users have found this unit to be effective for providing hot water for two bathrooms or a combination of shower, sink, and dishwasher. Its self-modulating capabilities mean it only uses the energy it needs, contributing to potential energy savings. It's often lauded for its easy installation process, especially when replacing an old unit.
Trade-offs
While rated for whole-house use in many scenarios, homes with exceptionally high hot water demands, such as those with multiple instantaneous showers running concurrently, might find its flow rate limiting. It also requires a compatible 60-amp electrical circuit.
10. 18kW Tankless Water Heater Electric 240V
10. 18kW Tankless Water Heater Electric 240V
This WINTEMP 18kW model is a solid mid-range option, offering a good balance of heating power and flow rate for many typical households. It features WiFi control for added convenience and a clear LED display for temperature monitoring.
Why I picked it
The 18kW power rating allows this unit to provide up to 4.3 GPM at a 40°F temperature rise, which is sufficient for many homes with two to three simultaneous hot water demands, like a shower and a sink. The WiFi control feature offers convenient temperature adjustments via a smartphone app, a feature often found in more expensive models. It is ETL certified.
Key specs
- Power Input: 18kW
- Voltage: 240V
- Max Flow Rate: 4.3 GPM (at 40°F temperature rise)
- Temperature Range: 86-131°F
- Dimensions: 18.3 x 12.6 x 4.7 inches
- Weight: 12.5 lbs
Real-world experience
Many users find this model to be an excellent upgrade for a standard family home, capable of supporting a shower, dishwasher, and washing machine usage without issues. The smart features are a definite plus, with owners appreciating the ability to adjust water temperature remotely. It’s noted for its compact design, which is often easier to fit into utility spaces.
Trade-offs
This unit requires a dedicated 80-amp breaker, so ensuring your electrical panel can accommodate this is crucial. While it offers good performance for its power class, households with extremely high simultaneous hot water demands might still benefit from a higher kW unit.
How I picked
When I was putting together this list of the best tankless electric hot water heaters, I focused on a few key things that matter most for everyday use. First, I looked at the power output (kW), because this directly translates to how much hot water the unit can produce at a given time. Higher kW generally means a higher flow rate.
Next, I considered the flow rate (GPM), especially at different temperature rises. A unit might boast a high GPM, but if that's only with a small temperature increase, it’s not very useful in colder climates. I paid attention to units that offered a good flow rate at typical temperature rises you’d expect for showering or washing dishes.
I also dug into user reviews, looking for consistent positive feedback on reliability, ease of installation, and actual performance compared to manufacturer claims. I noted common complaints, like units struggling with multiple fixtures or requiring expensive electrical upgrades. Lastly, I considered brand reputation and certifications like ETL, which indicate the product meets safety and performance standards. I didn't test the long-term durability beyond what aggregated user feedback suggested, nor did I perform specific water hardness tests on each unit.
Buying guide — what actually matters for Best Tankless Electric Hot Water Heater
So, you're ready to make the switch to a tankless electric water heater. That’s awesome! But before you click "buy," let's chat about what's really important to consider. It’s not just about picking the prettiest one; it's about finding the right fit for you.
How much hot water do you actually need? (Flow Rate & GPM)
This is probably the most crucial factor. Think about how many hot water taps you might use at once. Do you have simultaneous showers? Do you run the dishwasher while someone else is showering?
You'll want to look at the Gallons Per Minute (GPM) rating, but specifically, check the GPM at a certain temperature rise. For example, if your cold water is 50°F and you want your shower at 105°F, that's a 55°F rise. A unit with a higher GPM at that rise will serve you better.
How big should the heater be? (Power Input / kW)
The power, measured in kilowatts (kW), is directly related to the GPM. A higher kW unit can heat more water faster. For a single sink or a small apartment, a lower kW unit (like 8-11 kW) might be fine. For a whole house with multiple bathrooms, you’re likely looking at 18 kW, 24 kW, or even higher.
Make sure your home's electrical system can handle the load.
Can your electrical panel handle it? (Voltage & Amperage)
This is super important and often overlooked. Most tankless electric heaters run on 240V, requiring a dedicated circuit. The amperage draw can be significant, a 24kW unit might need a 100-amp dedicated breaker. If your electrical panel is already full or doesn't have the capacity, you'll need an electrician to upgrade it, which adds to the total cost.
Always check the manufacturer's specifications for electrical requirements.
Installation realities: Where will it go?
Tankless heaters are generally much smaller than traditional tank heaters, which is a huge plus for saving space. However, you still need to consider where it will be mounted. Does it need to be vertical? Does it have specific venting requirements (though electric ones usually don't vent like gas)?
Think about proximity to your main water lines and the electrical panel.
What about future-proofing and efficiency?
While electric tankless heaters are generally more energy-efficient than tank models because they only heat water on demand, some have better self-modulating technology than others. This means they adjust their power consumption based on how much hot water you're actually using, leading to further savings. Look for units that are Energy Star certified if that’s a priority.
Frequently Asked Questions (FAQ)
Is a tankless electric hot water heater worth it for a small apartment?
For a small apartment, a tankless electric water heater can definitely be worth it. You’ll benefit from continuous hot water for your shower and sink without the wait time associated with tank heaters. Smaller, lower-kW models designed for point-of-use are often sufficient and can be more energy-efficient as they only heat water when you need it, reducing standby energy losses from a tank heater.
How many showers can I run at once with a tankless electric water heater?
The number of showers you can run simultaneously depends heavily on the heater's power (kW) and its maximum flow rate (GPM) at the required temperature rise. A higher-powered unit (like 18kW-27kW) with a higher GPM is needed for multiple simultaneous showers. Lower-powered units (8-14kW) are typically designed for one shower at a time, or one shower plus a low-demand fixture like a sink. Always check the GPM rating for your expected temperature rise.
Do tankless electric water heaters require a lot of maintenance?
Tankless electric water heaters generally require less maintenance than tank heaters. The primary maintenance task is descaling the heating elements, especially if you live in an area with hard water. This involves flushing the unit with a descaling solution periodically, typically once a year or every few years, depending on water quality. Other than that, regular visual checks for leaks or damage are usually sufficient.
What's the typical lifespan of a tankless electric water heater?
A well-maintained tankless electric water heater can last significantly longer than a traditional tank water heater, often between 15 to 20 years. This extended lifespan is partly due to their simpler design with fewer moving parts compared to tank units, and because they are not constantly holding and heating a large volume of water, which can put less stress on the components over time.
Can I install a tankless electric water heater myself?
While some basic models might be simple to swap in, installing a tankless electric water heater often involves significant electrical work. Most units require a dedicated high-amperage circuit (240V), which may necessitate running new wiring or upgrading your home's electrical panel. Because of these electrical complexities and potential plumbing connections, it's generally recommended to have a qualified electrician and plumber perform the installation to ensure safety and proper function.
Final verdict
If you're looking to upgrade your hot water system, going tankless electric offers a fantastic blend of convenience and efficiency. For most households seeking reliable, on-demand hot water, the Rheem 18kW 240V Tankless Electric Water Heater is a top-tier choice, offering great performance and durability.
If you're prioritizing value and need robust heating power, the Rheem RTEX-24 24kW 240V Electric Tankless provides excellent output for its class. For smaller spaces or single-application needs, the EcoSmart ECO 11 Electric Tankless Water Heater remains a smart, efficient option.
Affiliate disclosure: This post contains affiliate links. If you buy through one of these links, I may earn a small commission at no extra cost to you. It never changes my recommendation, I only suggest gear I'd actually buy myself.
