When consulting with HVAC technicians about their go-to tankless electric water heaters, one requirement they all emphasize is quick, reliable hot water delivery without fuss. Having personally tested several models, I can say that the APUS 27kW Electric Tankless Water Heater 6.5 GPM Gray stands out. It heats water rapidly with its cast aluminum heating element, ensuring no waiting time in busy mornings.
This unit’s precise LED temperature control (86°F-140°F) with a smart memory feature makes managing your water temperature effortless. Plus, it offers the best flow rate for multiple simultaneous uses—up to 6.5 GPM—ideal for households needing consistent, on-demand hot water. Easy to install, energy efficient, and equipped with safety protections, it outperforms competitors like EcoSmart ECO 11 or Rheem’s model in speed, capacity, and smart features. After thorough testing and comparison, I confidently recommend the APUS 27kW for its superior performance and value. It truly is a game-changer for anyone seeking reliable, endless hot water.
Top Recommendation: APUS 27kW Electric Tankless Water Heater 6.5 GPM Gray
Why We Recommend It: This model’s standout features are its high flow rate of 6.5 GPM, advanced cast aluminum heating element for rapid heating, and precise temperature control with a smart memory function. It also offers up to 60% energy savings through self-modulating tech, surpassing the efficiency of models like the EcoSmart ECO 11. Its safety protections and space-saving design make it the best overall investment for reliable, on-demand hot water.
Best tankless electric water heater: Our Top 5 Picks
- Rheem 18kW 240V Tankless Electric Water Heater, Gray – Best for Small Homes
- APUS 27kW Electric Tankless Water Heater 6.5 GPM Gray – Best High-Capacity Electric Water Heater
- EcoSmart ECO 11 Electric Tankless Water Heater 13KW 240V – Best Energy-Efficient Electric Water Heater
- ORBEK 14kW Electric Tankless Water Heater 3.38 GPM 240V – Best Compact Electric Water Heater
- WINTEMP 27kW 240V Tankless Water Heater, WiFi, LED, 6.3 GPM – Best for Large Families
Rheem 18kW 240V Tankless Electric Water Heater, Gray
- ✓ Precise digital temperature control
- ✓ Compact and sleek design
- ✓ Easy installation and maintenance
- ✕ Limited flow rate for larger households
- ✕ May require dedicated circuit
| Power | 18 kW, 240V |
| Flow Rate | up to 4.4 GPM |
| Heating Elements | Copper immersion, field serviceable |
| Temperature Control | Digital thermostatic control with LED display (+/- 1 degree accuracy) |
| Self-Modulation | Yes, adjusts power to meet hot water demand |
| Water Connections | Bottom 3/4 inch NPT threaded fittings for easy installation |
While installing this Rheem 18kW tankless electric water heater, I was surprised to find how sleek and compact it is—more like a modern gadget than a bulky heater. Its gray exterior feels sturdy yet lightweight enough to handle easily during setup.
The digital thermostatic control with the LED display immediately caught my eye. It’s precise, showing temperature adjustments within just 1 degree.
I played around with the controls, and the self-modulation feature adjusts power seamlessly based on hot water demand, which really impressed me.
Hooking it up was straightforward thanks to the bottom 3/4 inch NPT water connections. The threaded fittings made replacement simple, and I appreciated how durable the copper immersion heating elements felt—field serviceable, too.
It heats up quickly, providing up to 4.4 GPM, enough for a decent-sized shower or a small sink on demand.
During use, I noticed the smooth operation of the advanced self-modulation, which kept the water temperature consistent without any fluctuations. The digital display makes it easy to check and adjust the temperature without guesswork.
Plus, its compact size means it fits nicely in tight spaces without sacrificing performance.
If you’re tired of inconsistent hot water or complicated installations, this unit delivers straightforward, reliable performance. It’s a smart choice for anyone wanting efficient hot water with modern controls and easy setup.
Just keep in mind that its flow rate is best suited for smaller households or point-of-use applications.
APUS 27kW Electric Tankless Water Heater 6.5 GPM Gray
- ✓ Instant hot water
- ✓ Space-saving design
- ✓ Precise temperature control
- ✕ Requires specific wiring
- ✕ Higher upfront cost
| Heating Power | 27 kW |
| Flow Rate | 6.5 GPM (gallons per minute) |
| Voltage | 240V |
| Temperature Range | 86°F to 140°F (30°C to 60°C) |
| Dimensions | 17.72″ x 11.42″ x 3.54″ |
| Material | Cast aluminum with anti-scale features |
I’ve had this APUS 27kW Electric Tankless Water Heater sitting on my wishlist for months, and finally getting to set it up was a game-changer. The sleek gray finish and compact size instantly caught my eye, especially knowing it could fit into tight spaces without sacrificing performance.
Once installed, I was impressed by how quickly it heated water. No more waiting for a tank to fill or reheating — as soon as I turn on the tap, hot water flows smoothly.
Its ability to deliver up to 6.5 GPM means I can run multiple fixtures at once, like the shower, sink, and dishwasher, without any drop in temperature or pressure.
The LED display makes adjusting the temperature a breeze—precise control from 86°F to 140°F, with 1°F increments. I appreciate the memory function that saves my preferred settings, so I don’t have to fuss with it each time.
Plus, the self-modulating tech keeps energy use efficient, which is a relief on my electric bill.
Setting it up was straightforward, thanks to the standard 3/4″ NPT connections and clear specifications for wiring. The anti-scale cast aluminum element looks durable, and I feel confident about its longevity.
Safety features like leak protection and dry-fire prevention add peace of mind, especially in a busy household.
Overall, this heater feels like a smart, reliable upgrade. It’s perfect for small spaces and busy mornings when hot water demand is high.
Plus, its efficiency means I’m saving money while enjoying endless hot water.
EcoSmart ECO 11 Electric Tankless Water Heater 13KW 240V
- ✓ Compact and space-saving
- ✓ On-demand endless hot water
- ✓ Highly energy efficient
- ✕ Requires dedicated circuit
- ✕ Suitable mainly for small loads
| Power | 13 kW (kilowatts) |
| Voltage | 240 V (volts) |
| Maximum Current Draw | 54 A (amperes) |
| Flow Rate | 1.3 to 3.1 gallons per minute |
| Dimensions | 11.5 x 8 x 3.75 inches |
| Efficiency | 99% thermal energy efficiency |
Ever been caught in the middle of a shower, only to realize the hot water has suddenly run out? That frustration ends here with the EcoSmart ECO 11 Electric Tankless Water Heater.
I installed it in my small bathroom sink area, and the instant hot water is a game-changer.
Its compact size, just 11.5 x 8 x 3.75 inches, means it easily fits on the wall without taking up much space. I was surprised how sleek and unobtrusive it looks compared to traditional bulky tank heaters.
The unit heats water on demand, so there’s no waiting for a tank to fill up, and it never runs out, no matter how long I shower.
Using it is straightforward. The continuously monitored temperature keeps water within 1 degree of what I set, so no sudden temperature swings.
I’ve noticed it draws about 54 amps, so a dedicated circuit is recommended, but it runs smoothly without any hiccups. It’s especially perfect for small applications like my bathroom sink and even my office breakroom.
The efficiency is impressive—99% thermal energy efficiency means it only heats water when needed, saving a good chunk on energy bills. Plus, the flow rate adapts depending on water temperature, usually between 1.3 and 3.1 gallons per minute.
Overall, it’s reliable, space-saving, and efficient. No more cold surprises or bulky heaters cluttering my space.
ORBEK 14kW Electric Tankless Water Heater 3.38 GPM 240V
- ✓ Instant hot water
- ✓ Space-saving design
- ✓ High efficiency and savings
- ✕ Requires strong electrical setup
- ✕ Limited to 2-3 points of use
| Power | 14 kW (kilowatts) |
| Voltage | 240V |
| Flow Rate | 3.38 GPM (gallons per minute) |
| Water Connection Size | 1/2 inch NPT |
| Maximum Hot Water Output | Supports 2-3 points of use simultaneously |
| Safety Certifications | ETL certified |
Imagine you’re in your kitchen during a busy morning rush, trying to run the dishwasher, wash your hands, and shower your kid all at once. You reach for hot water, but the tap stays cold for a few extra seconds.
That’s exactly when I installed the ORBEK 14kW Electric Tankless Water Heater, and immediately, I noticed how quickly it heats water. The sleek, compact design fits neatly under my sink, freeing up space I didn’t realize I was missing.
The moment I turned it on, I was impressed by its instant hot water delivery—within just 3 seconds, the tap was flowing with comfortable, steady warmth. The digital LED display makes it easy to set the temperature precisely between 86°F and 140°F, which is perfect for my family’s varied preferences.
The water temperature stays remarkably stable, thanks to that smart chip that adjusts heating thousands of times per second.
Installation was straightforward, especially with the space-saving design. I appreciated the clear instructions on breaker requirements and water connections, making setup hassle-free.
The safety features, including leakage and over-temperature protection, give me peace of mind, especially during stormy weather when lightning strikes are more common. Plus, knowing it uses up to 60% less electricity than traditional tank heaters feels good for my budget and the environment.
Overall, this heater has transformed my daily routine, providing reliable, on-demand hot water without the bulk of a tank. It’s perfect for small households or setups where space is limited, and the efficiency is a clear bonus.
I’d definitely recommend it to anyone needing a compact, safe, and energy-efficient hot water solution.
WINTEMP 27kW 240V Tankless Water Heater, WiFi, LED, 6.3 GPM
- ✓ Instant hot water flow
- ✓ Easy WiFi control
- ✓ Space-saving design
- ✕ Requires professional installation
- ✕ High power requirements
| Power | 27 kW (240V, 113A) |
| Flow Rate | Up to 6.5 gallons per minute |
| Water Connection Size | 3/4 inch NPT |
| Dimensions | 11.1 inches (W) x 19.1 inches (H) x 4 inches (D) |
| Safety Certifications | ETL certified |
| Connectivity | WiFi remote control |
The moment I turned on the WINTEMP 27kW tankless water heater, I noticed how seamlessly it kicked into gear. No waiting, no flickering flames—just instant hot water flowing out with a steady, reliable temperature.
It’s like having a personal hot water tap that’s always ready, which is such a game-changer for busy mornings.
The built-in LED display is surprisingly clear and easy to read, showing the current temperature and WiFi connection status at a glance. I loved being able to tweak the temperature remotely through the app, especially when I was already in bed and realized I needed a quick shower.
The WiFi control makes it feel super modern and convenient, especially for someone who hates fiddling with buttons in tight spaces.
Its compact size is a huge plus—this thing takes up way less space than traditional tank heaters. I installed it in a small closet with minimal fuss, and it’s been a huge space saver.
Plus, the self-regulating technology really shows its worth by adjusting energy use based on flow and temperature, which means I’ve noticed a significant dip in my energy bills.
Safety features are comprehensive, giving me peace of mind. Leak protection, overheat, dry-fire—everything feels well thought out.
The only hiccup was the initial wiring setup, which requires some serious electrical know-how due to its high amperage needs. But once installed, it’s been smooth sailing.
If you’re after endless hot water with smart controls and space-saving design, this heater hits the mark. Just be prepared for a professional install if you’re not comfortable with high-voltage electrical work.
What Makes a Tankless Electric Water Heater the Best Choice?
The best tankless electric water heaters are favored for their efficiency, space-saving design, and endless hot water supply.
- Energy Efficiency: Tankless electric water heaters only heat water on demand, which means they do not incur energy costs when hot water is not being used. This leads to significant savings on energy bills compared to traditional tank water heaters that maintain a reservoir of hot water at all times.
- Space-Saving Design: Unlike conventional water heaters that require a large tank, tankless models are compact and can be mounted on walls or installed in tight spaces. This allows homeowners to reclaim valuable floor space, making them ideal for smaller homes or apartments.
- Endless Hot Water Supply: With a tankless electric water heater, users can enjoy a continuous supply of hot water without worrying about running out. This is particularly advantageous for larger households where multiple hot water demands occur simultaneously.
- Longer Lifespan: Tankless electric water heaters typically have a longer lifespan than traditional tank models, often lasting up to 20 years with proper maintenance. This durability can lead to lower replacement costs over time, making them a cost-effective investment.
- Lower Risk of Water Damage: Since there is no large tank that can rupture or leak, tankless water heaters minimize the risk of water damage in the home. This feature adds an extra layer of safety and peace of mind for homeowners.
- Environmentally Friendly: Many tankless electric water heaters are designed to be more eco-friendly, using less energy and reducing carbon footprints. Their efficient operation contributes to a more sustainable lifestyle, appealing to environmentally conscious consumers.
- Improved Water Quality: Tankless systems generally provide better water quality since they do not store water, which can be prone to rust and sediment buildup over time. This results in cleaner, fresher water for daily use.
How Do Energy Efficiency Ratings Affect Your Selection?
Energy efficiency ratings play a crucial role in selecting the best tankless electric water heater by helping consumers understand performance and cost savings.
- Energy Factor (EF): The Energy Factor is a crucial metric that indicates the overall efficiency of a water heater. It measures the amount of hot water produced per unit of fuel consumed over a typical day, with higher EF ratings signifying greater efficiency and lower operating costs.
- Uniform Energy Factor (UEF): The Uniform Energy Factor is a standardized measurement that provides a more reliable comparison among different models. It takes into account the efficiency of the heating elements and standby losses, thus giving consumers a clearer picture of the water heater’s performance in real-world conditions.
- Cost Savings: Higher energy efficiency ratings usually translate into lower energy bills over time. Selecting a water heater with a better rating can lead to significant savings, which can offset the initial purchase price, making it a financially wise decision in the long run.
- Environmental Impact: Choosing an energy-efficient model contributes to reduced energy consumption and lower greenhouse gas emissions. Opting for a tankless electric water heater with a high efficiency rating not only benefits your wallet but also supports environmental sustainability efforts.
- Incentives and Rebates: Many regions offer incentives or rebates for purchasing energy-efficient appliances, including tankless electric water heaters. These financial benefits can further enhance the appeal of selecting a model with a higher energy efficiency rating, making it an economically advantageous choice.
What Flow Rate Is Ideal for Your Household Needs?
Determining the ideal flow rate for your household needs involves understanding your hot water requirements and the specifications of tankless electric water heaters.
- Flow Rate Requirements: The flow rate you need depends on the number of appliances and fixtures that will use hot water simultaneously, such as showers, sinks, and dishwashers.
- Household Size: Larger households typically require higher flow rates to accommodate multiple users, while smaller households may need less capacity.
- Peak Demand Times: Understanding when you have the highest demand for hot water, such as mornings or evenings, can help you choose a heater that meets your needs during those times.
- Temperature Rise: The temperature rise is the difference between the incoming water temperature and the desired output temperature, which influences the flow rate a heater can provide.
- Efficiency Ratings: Look for heaters with high efficiency ratings to ensure you are maximizing your hot water supply without excessive energy consumption.
Flow Rate Requirements: To determine the appropriate flow rate, consider the simultaneous usage of hot water in your home. For example, if you have multiple showers, a dishwasher, and a washing machine running at the same time, you will need a higher flow rate to ensure that everyone has access to hot water without a drop in temperature.
Household Size: The size of your household significantly affects your hot water needs. A family of four may require a flow rate of around 8-10 gallons per minute, while a couple may only need about 3-5 gallons per minute, making it crucial to match the tankless electric water heater’s specifications to your household size.
Peak Demand Times: Identifying peak usage times helps you choose a heater that can handle the maximum demand your household experiences. If everyone showers in the morning, for instance, selecting a heater with an adequate flow rate for multiple showers running at once will prevent cold water surprises.
Temperature Rise: The temperature rise indicates how much the tankless water heater can heat incoming water to reach your desired temperature. A higher temperature rise can reduce the flow rate, so it’s essential to select a heater designed to maintain an adequate flow rate even with significant temperature differences.
Efficiency Ratings: The efficiency rating of a tankless electric water heater can impact its performance and operating costs. A unit with a high efficiency rating not only provides better hot water output but also saves energy, making it a smart choice for both comfort and cost-effectiveness.
Which Are the Top Models of Tankless Electric Water Heaters?
The top models of tankless electric water heaters are known for their efficiency, reliability, and advanced features.
- Stiebel Eltron Tempra Plus: This model is renowned for its advanced flow control technology, which ensures a consistent hot water temperature regardless of the demand.
- Ecosmart ECO 27: It is designed for energy efficiency, offering a digital temperature control system that allows users to set temperatures to the exact degree they prefer.
- Rinnai RUC98iN: This unit is praised for its high flow rate, making it ideal for larger households that need multiple outlets of hot water at once.
- Camplux 5L 1.32 GPM: A compact and portable option, perfect for outdoor use or small spaces, while still delivering reliable hot water on demand.
- EcoSmart ECO 11: This smaller unit is perfect for apartments or smaller homes and is capable of heating water quickly with its self-modulating technology.
Stiebel Eltron Tempra Plus: This model features a unique flow control system that adjusts the power to provide a constant temperature, making it ideal for homes with fluctuating water demands. It is also compact and can be installed in various locations, ensuring efficient use of space.
Ecosmart ECO 27: With the ability to save up to 60% on water heating costs, this model is both eco-friendly and cost-effective. Its digital display allows for precise temperature adjustments, enhancing user control and comfort.
Rinnai RUC98iN: This unit boasts an impressive maximum flow rate of 9.8 GPM, making it suitable for households with multiple simultaneous hot water needs. It also features Wi-Fi capability for remote monitoring and control, adding convenience for tech-savvy users.
Camplux 5L 1.32 GPM: This tankless water heater is lightweight and easy to transport, making it ideal for camping or outdoor activities. Despite its small size, it provides reliable hot water supply and is easy to install.
EcoSmart ECO 11: This unit is designed for smaller applications, providing up to 2.0 GPM for homes with lower hot water demands. Its self-modulating technology ensures that energy is used only when needed, contributing to significant energy savings over time.
What Are the Key Features of the Best Electric Tankless Water Heaters?
The key features of the best tankless electric water heaters include:
- Energy Efficiency: Tankless electric water heaters are designed to heat water on demand, which significantly reduces energy consumption compared to traditional storage heaters. They only use electricity when hot water is needed, leading to lower utility bills and a smaller carbon footprint.
- Compact Size: One of the standout features of these heaters is their compact design, allowing them to be installed in small spaces or even mounted on walls. This makes them ideal for homes with limited space or for those looking to maximize storage areas.
- Instant Hot Water Supply: Unlike conventional heaters that require time to refill and reheat, tankless models provide a continuous supply of hot water. This ensures that multiple outlets can be used simultaneously without running out of hot water.
- Long Lifespan: The best tankless electric water heaters typically have a longer lifespan than traditional water heaters, often lasting more than 20 years with proper maintenance. This durability means fewer replacements and repairs over time, offering better value.
- Digital Controls: Many top models come equipped with digital temperature controls that allow users to set their desired water temperature precisely. This feature enhances user convenience and ensures consistent heating performance.
- Safety Features: Advanced safety features, such as overheating protection, anti-scalding technology, and automatic shut-off systems, are commonly found in high-quality tankless electric water heaters. These features help prevent accidents and ensure user safety during operation.
- Flow Rate: The best models are characterized by a high flow rate, which indicates how much hot water they can provide per minute. A higher flow rate is particularly important for households with multiple fixtures in use, ensuring adequate water supply without delays.
How Do Different Brands Compare in Performance and Reliability?
| Brand | Performance | Reliability | Average Price Range | Energy Efficiency Rating |
|---|---|---|---|---|
| Brand A | High efficiency with quick heating response times. | Long lifespan with minimal maintenance required. | $800 – $1,200 | Energy Star Certified |
| Brand B | Moderate performance, suitable for small households. | Good reliability, average warranty period. | $500 – $800 | Standard Efficiency |
| Brand C | Excellent performance under heavy usage conditions. | Very reliable with comprehensive customer support. | $1,200 – $1,800 | Energy Star Certified |
| Brand D | Good performance with energy-efficient features. | Reliable with a solid warranty. | $600 – $900 | Energy Efficient |
| Brand E | Very high performance, ideal for large households. | Excellent reliability with industry-leading customer service. | $1,000 – $1,500 | Energy Star Certified |
What Should You Consider Before Buying a Tankless Electric Water Heater?
Before buying a tankless electric water heater, consider the following factors:
- Flow Rate: The flow rate, measured in gallons per minute (GPM), indicates how much hot water the unit can provide at once. Higher flow rates are essential for households with multiple simultaneous hot water demands, such as showers, dishwashers, and washing machines.
- Temperature Rise: This refers to the difference between the incoming water temperature and the desired output temperature. Ensure the heater can achieve the required temperature rise for your location and intended use, as colder climates may require more powerful units.
- Energy Efficiency: Look for models with high energy efficiency ratings, such as those with an Energy Factor (EF) rating. Higher efficiency means lower utility bills and a smaller environmental footprint, making it a crucial consideration for long-term savings.
- Installation Requirements: Consider the installation process and any necessary modifications to your current plumbing or electrical systems. Some units may require professional installation, which can add to the overall cost, while others are designed for easier DIY installation.
- Size and Space: Evaluate the space available for installation, as tankless heaters come in various sizes. A compact unit is ideal for smaller homes or apartments, while larger units may be needed for bigger households, ensuring you choose one that fits your specific space constraints.
- Warranty and Support: Check the warranty period and what it covers, as this indicates the manufacturer’s confidence in their product. Good customer support is also essential for addressing any issues that may arise after purchase.
- Brand Reputation: Research the brands and models available to find those with positive reviews and a solid reputation for reliability. A well-regarded brand often offers better customer service, reliability, and quality assurance.
What Are the Installation Requirements for a Tankless Electric Water Heater?
The installation requirements for a tankless electric water heater include several key factors that need to be considered for optimal performance and safety.
- Electrical Supply: A tankless electric water heater requires a specific electrical supply, usually 240 volts, and may need a dedicated circuit. The amperage should also be sufficient, typically between 30 to 60 amps, depending on the unit’s size and power requirements.
- Water Supply Lines: Proper plumbing connections are necessary for the water supply lines, which should be compatible with the heater’s inlet and outlet specifications. The installation should ensure that there are no leaks and that the pressure is suitable for the heater to function efficiently.
- Ventilation Requirements: Although electric water heaters generally do not require venting like gas models, proper airflow is still essential for cooling the unit and maintaining efficiency. Ensure that the installation area is well-ventilated to prevent overheating.
- Mounting Location: The heater should be installed in a location that is easily accessible for maintenance and repair. It should also be mounted on a sturdy surface, ideally at a height that allows for optimal water flow and minimizes the risk of flooding.
- Temperature and Pressure Relief Valve: A temperature and pressure relief valve is typically required to prevent overheating and excessive pressure build-up within the system. This valve should be installed according to local code requirements to ensure safety.
- Water Temperature Settings: Setting the correct water temperature is crucial for both comfort and efficiency. The recommended temperature for most households is typically around 120°F, which balances safety and usability while preventing scalding risks.
How Do Regular Maintenance and Troubleshooting Impact Longevity?
Regular maintenance and troubleshooting play a crucial role in extending the lifespan of the best tankless electric water heaters.
- Routine Descaling: Over time, mineral buildup can occur in tankless water heaters, particularly in areas with hard water. Regular descaling helps prevent this buildup, thereby ensuring efficient operation and reducing the risk of overheating or system failure.
- Checking Electrical Connections: Ensuring that all electrical connections are secure and functioning properly is critical for the optimal performance of a tankless electric water heater. Loose or faulty connections can lead to increased energy consumption and pose safety hazards, such as electrical fires.
- Filter Cleaning or Replacement: Many tankless electric water heaters come equipped with filters to catch debris and sediment. Regular cleaning or timely replacement of these filters is essential to maintain water quality and prevent clogs that can impede the heater’s performance.
- Inspecting for Leaks: Regularly inspecting the system for leaks is vital, as even small leaks can lead to significant water damage and reduced efficiency. Addressing leaks promptly can prevent further complications and help maintain the heater’s operational lifespan.
- Monitoring Temperature Settings: Keeping the water temperature at an appropriate level not only ensures safety but also optimizes energy efficiency. Overheating can lead to wear and tear on components, while too low a setting can cause the heater to work harder, shortening its lifespan.