When searching for the best electric tankless water heaters, the key considerations are size, power, and efficiency. The Stiebel Eltron Tempra 29 Plus stands out as the overall top choice thanks to its reliable performance and advanced temperature control. For those seeking smart features, the Westinghouse 14kW WiFi model offers seamless connectivity with Alexa and Google Home. Budget-conscious buyers will find the EcoSmart ECO 11 delivers good value at a lower price point, while the EcoSmart ECO 18 provides higher capacity for larger households. The main tradeoffs include balancing upfront cost, installation complexity, and power capacity. Continue reading for a detailed breakdown of these top options and what makes each one unique.
Key Takeaways
- Higher wattage models like EcoSmart ECO 18 are better suited for larger households needing higher flow rates.
- Smart features such as WiFi connectivity add convenience but often come at a higher price and complexity.
- Build quality and certifications like ETL ensure safety and reliability, especially for indoor installations.
- Price varies significantly; budget models like EcoSmart ECO 11 offer good value but may have limited flow capacity.
- Installation requirements, including electrical panel capacity, are critical factors to avoid costly upgrades.
More Details on Our Top Picks
Stiebel Eltron Tempra 29 Plus Tankless Electric Water Heater
The Stiebel Eltron Tempra 29 Plus stands out as the best overall choice for those seeking reliable, continuous hot water in warm climates. Its German engineering emphasizes high efficiency and energy savings, making it ideal for whole-home use where space is limited. Compared with smaller models like the EcoSmart ECO 11, it offers a higher flow rate and automatic temperature control, but requires a dedicated 40 amp breaker and significant electrical upgrades, which may not suit every home. Its built-in LED display and preset options enhance user convenience. The main tradeoff involves the need for professional electrical installation and its suitability primarily for warm climate regions. This pick makes the most sense for homeowners who want a durable, high-capacity heater with a focus on efficiency and space-saving design.
Pros:- Continuous and unlimited hot water supply for entire home
- Space-saving wall-mounted design requiring no venting
- Automatic temperature presets and LED display
Cons:- Requires dedicated 40 amp breakers and high gauge wiring
- High power draw may necessitate electrical upgrades
Best for: Homeowners in warm climates needing reliable whole-house hot water with energy efficiency
Not ideal for: Homes in colder regions or those with limited electrical capacity, due to high power demands
- Power Source:Hard wiring required
- Wattage:28,800 Watts
- Voltage:240 Volts
- Flow Rate:3 Gallons Per Minute
- Maximum Pressure:150 PSI
- Efficiency:High efficiency
Bottom line: This model is best suited for homeowners in warm climates who prioritize efficiency and space savings despite requiring electrical upgrades.
Westinghouse 14kW 240V Smart WiFi Tankless Water Heater Electric, Compatible with Alexa & Google Home, ETL Certified, IPX4, Gray – Upgrade
The Westinghouse APOLO-2.0 excels as a smart, compact unit perfect for small homes or apartments where remote monitoring and voice control enhance convenience. Its Wi-Fi connectivity and compatibility with Alexa and Google Home give it a technological edge over simpler models like the EcoSmart ECO 11, especially for tech-savvy users. However, its flow rate of 3.38 GPM may fall short for larger households with multiple fixtures running simultaneously, unlike the more powerful EcoSmart ECO 18. Its ETL certification ensures safety and durability, but installation requires hard wiring and a dedicated breaker. This heater makes sense for those who want smart features for small-scale hot water needs, with the tradeoff being limited capacity for larger households.
Pros:- Wi-Fi enabled for remote control and voice commands
- Space-efficient wall-mounted design
- Suitable for multiple points of use in small setups
Cons:- Flow rate may be insufficient for larger households
- Requires hard wiring and breaker installation
Best for: Small households or apartments wanting remote control and smart home compatibility
Not ideal for: Larger families with high hot water demands or in colder climates, due to limited flow rate and temperature range
- Power:14 kW
- Voltage:240 V
- Flow Rate:3.38 GPM
- Maximum Temperature:140°F
- Maximum Pressure:120 PSI
- Certifications:ETL
Bottom line: Ideal for small households seeking smart control and remote operation, but less suitable for bigger families or colder regions.
EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts
The EcoSmart ECO 11 is tailored for those who need a compact, energy-efficient solution for small applications like sinks or single bathrooms. Its self-modulating technology ensures consistent temperature with minimal energy waste, making it a strong contender among low-capacity units. Compared to the EcoSmart ECO 18, it has a lower flow rate (up to 3.1 GPM) and is less suitable in colder climates, where incoming water temperature drops below 62°F. Its small size and high efficiency make it ideal for limited spaces, but it can’t support larger households or simultaneous multiple fixtures. Electrical requirements include a 240V supply and high amperage, which could be a hurdle in some homes. This model is perfect for individuals or small households prioritizing efficiency and space saving but not volume.
Pros:- Compact size saves space
- High energy efficiency with self-modulating tech
- Provides on-demand hot water for small applications
Cons:- Limited flow rate, not suitable for multiple fixtures
- Requires high amperage and proper wiring
Best for: Single fixtures or small bathrooms in warm climates where space is limited
Not ideal for: Larger households or cold climates, due to limited flow rate and temperature performance
- Power:13 kW
- Voltage:240 V
- Flow Rate:1.3 to 3.1 GPM
- Efficiency:99%
- Dimensions:11.5 x 8 x 3.75 inches
- Suitable Climate:62°F and above
Bottom line: Best for small-scale, space-conscious applications in warm climates, but not for larger households or cold regions.
EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts
The EcoSmart ECO 18 is designed for households in warmer climates where incoming water temperatures stay above 62°F, enabling it to supply over 2.5 GPM. Its digital temperature control with 1-degree precision allows for accurate hot water settings, making it suitable for simultaneous use of multiple fixtures, unlike smaller units. It requires two 40A double-pole breakers and proper wiring, which could pose installation challenges. Compared to the ECO 11, it offers higher flow capacity but still struggles in colder climates or in homes with high hot water demands. Its focus on efficiency and multiple fixture support makes it a good choice for small to medium households in suitable climates, but less so in colder regions.
Pros:- Digital temperature control with 1-degree accuracy
- Supports multiple fixtures simultaneously
- Suitable for warm climates with incoming water above 62°F
Cons:- Requires proper wiring and double breaker setup
- Less effective in cold climates below 62°F
Best for: Warm climate households needing multiple fixtures simultaneously
Not ideal for: Homes in colder climates or with high hot water demands beyond 2.5 GPM
- Power:18 kW
- Voltage:240 V
- Flow Rate:Over 2.5 GPM
- Temperature Control:Digital, 1-degree increments
- Suitable Climate:62°F and above
- Dimensions:17 x 14 x 3.5 inches
Bottom line: A strong choice for small to medium homes in warm regions with multiple fixture needs, but not for colder climates.
Rheem 240V Tankless Electric Water Heater RTEX-13, Gray
The Rheem RTEX-13 offers a straightforward, reliable solution for on-demand hot water with a flow rate up to 3.17 GPM. Its external digital thermostat and LED display provide precise temperature control, making it easy to dial in settings for consistent comfort. Compared with the EcoSmart ECO 11, it features a similar power rating but benefits from a durable copper heating element known for longevity. Its simple wall-mounted installation makes it accessible for DIY enthusiasts or professional installers. However, the flow rate can limit its effectiveness in larger households or simultaneous fixture use, and it requires a 240V circuit, possibly needing electrical upgrades. Overall, it strikes a balance between reliability, control, and ease of installation, suited for small to medium households.
Pros:- Energy-efficient with 99.8% efficiency
- External digital thermostat for precise control
- Durable copper heating elements ensure longevity
Cons:- Flow rate may be insufficient for larger households
- Requires professional electrical installation in some cases
Best for: Small to medium households needing reliable, adjustable hot water without complicated features
Not ideal for: Large households or high-demand scenarios where higher flow rates are essential
- Power Source:Electric
- Wattage:13 KW
- Voltage:240 V
- Flow Rate:up to 3.17 GPM
- Maximum Temperature:140°F
- Material:Copper
Bottom line: Ideal for small to medium homes requiring dependable, adjustable hot water with straightforward installation and control.
14kW Electric Tankless Water Heater, On Demand Instant Hot Water, 240V, Max 3.38 GPM, Indoor Use, ETL Certified, Upgraded 2.0
This 14kW unit stands out for its reliable performance in providing instant hot water for 2-3 fixtures, making it ideal for small households or point-of-use applications. Compared to larger models like the ECOTOUCH 27kW, it delivers a lower flow rate—up to 3.38 GPM—so it’s less suitable for bigger households but excels in space-saving and energy efficiency. Its advanced safety features and high-efficiency design help reduce energy bills, yet it demands a dedicated 240V/60AMP circuit, which could complicate installation. For those needing a simple, indoor solution without excessive electrical upgrades, this heater offers a balanced mix of safety, performance, and compactness.
Pros:- Provides instant, continuous hot water for multiple fixtures
- Energy-efficient with up to 60% savings over traditional tank heaters
- Compact, wall-mounted design suitable for small spaces
- Includes advanced safety protections like leakage and over-temperature safeguards
Cons:- Requires a dedicated 240V/60AMP circuit, complicating installation
- Flow rate limited to 3.38 GPM, not suitable for large households or simultaneous multiple fixtures
Best for: Small households or single-bathroom homes seeking reliable, space-efficient hot water.
Not ideal for: Larger families or homes with multiple bathrooms, as it can’t support higher flow demands.
- Power:14 kW
- Voltage:240V
- Flow Rate:3.38 GPM
- Temperature Range:86°F – 140°F
- Material:Metal
- Dimensions:14.2″H x 9.5″L x 3.1″W
Bottom line: This model is ideal for small spaces needing dependable hot water without extensive electrical upgrades.
ECOTOUCH 27kW 240V Tankless Electric Water Heater, Instant Hot Water, Up to 6.5 GPM, Self-Modulating, ETL Certified
The ECOTOUCH 27kW model makes a compelling case for homes needing higher flow capacity, offering up to 6.5 GPM—almost double that of the Rheem 18kW. Its self-modulating technology adapts power usage based on demand, helping to lower energy bills, and it features a sleek touch panel for user-friendly control. This makes it better suited than the Rheem 18kW for small homes with multiple outlets, though it comes with the tradeoff of requiring a high-amperage electrical setup, which could mean professional installation and potential upgrade costs. Compared to the Rheem, it offers greater flow and efficiency but at the expense of more complex wiring and higher initial investment.
Pros:- Provides instant, endless hot water at up to 6.5 GPM
- Self-modulating system reduces energy consumption
- User-friendly touch control panel
- High safety standards with multiple protections
Cons:- Requires significant electrical capacity, potentially needing professional wiring
- Installation complexity could increase upfront costs
- Designed mainly for small to medium homes, not large households
Best for: Small to medium-sized homes or apartments that need reliable hot water for multiple fixtures simultaneously.
Not ideal for: Large households with high simultaneous hot water demands, as electrical requirements may be prohibitive.
- Power:27 kW
- Voltage:240 V
- Flow Rate:Up to 6.5 GPM
- Maximum Temperature:131°F
- Material:High End Glass
- Certifications:ETL, UL
Bottom line: This model suits small to medium residences needing high hot water flow with energy-efficient operation.
Rheem 18kW 240V Tankless Electric Water Heater, Gray
The Rheem 18kW heater strikes a balance between capacity and simplicity, delivering up to 4.4 GPM—making it suitable for small to mid-range applications like single bathrooms or point-of-use installations. Its digital thermostatic control and self-modulation technology help ensure energy savings, while its compact design allows flexible mounting options. This makes it a practical choice for those who want a straightforward, reliable heater without the complexity of high amperage electrical requirements. Compared to the ECOTOUCH 27kW, it offers less flow—more aligned with moderate household needs—though it may fall short if multiple fixtures are used simultaneously or demand higher flow rates.
Pros:- Provides continuous, dependable hot water supply
- Energy-efficient with self-modulating technology
- Compact size and easy to install
- Digital temperature display for precise control
Cons:- Flow rate limited to 4.4 GPM, may not serve multiple fixtures at once
- Installation may require professional plumbing and electrical work
- Less suited for large households with high demand
Best for: Small to mid-sized homes needing reliable hot water for one or two fixtures with straightforward installation.
Not ideal for: Large households or simultaneous multiple fixture use, due to its limited flow rate and capacity.
- Power:18,000 watts
- Voltage:240 Volts
- Flow Rate:4.4 GPM
- Maximum Temperature:140°F
- Material:Stainless Steel
- Efficiency:99.8%
Bottom line: This heater offers a reliable, space-efficient solution for small to mid-sized homes with modest hot water needs.
How We Picked
The products in this roundup were evaluated based on a combination of performance, usability, build quality, and value. I considered wattage and flow rate to determine capacity, ensuring each unit can meet typical household needs. Ease of installation and available features, such as WiFi connectivity or self-modulation, helped differentiate models. Safety certifications and user reviews were also factored in to ensure reliability and durability. The ranking reflects a balance between cost-effectiveness and high performance, with an emphasis on products that suit different household sizes and user preferences.Factors to Consider When Choosing Best Electric Tankless Water Heaters
Choosing the best electric tankless water heater involves several key factors beyond just price. Understanding these considerations can help you avoid common pitfalls and select a unit that fits your home’s needs and your budget. From flow rate to energy efficiency, each aspect impacts long-term satisfaction and operation costs.Flow Rate and Power Capacity
One of the most important factors is the flow rate, measured in gallons per minute (GPM). Larger households or multiple fixtures running simultaneously demand higher flow rates, which require models with greater wattage. Selecting a unit with insufficient capacity can lead to cold water shocks, while over-specifying can increase upfront costs unnecessarily. Evaluate your household’s peak hot water needs to find a model that strikes the right balance.
Energy Efficiency and Operating Costs
Electric tankless water heaters are generally more efficient than traditional tanks, but differences exist among models. Look for units with self-modulating technology, which adjusts power usage based on demand, reducing energy waste. Certifications like ENERGY STAR can serve as indicators of higher efficiency. Remember, a more efficient heater can save money over time, even if it costs more initially.
Installation Requirements
Proper electrical wiring and panel capacity are vital. Some units require dedicated circuits, and upgrading your electrical system can add to the overall cost. Space considerations also matter; compact models are easier to install in tight spaces. Always verify your home’s electrical infrastructure matches the unit’s specifications before purchase to avoid surprises during installation.
Smart Features and Connectivity
Smart-enabled models with WiFi or app controls offer convenience, allowing you to manage temperature and monitor usage remotely. These features are especially appealing for tech-savvy households but tend to come with a higher price tag. Consider whether the added control justifies the extra investment based on your lifestyle and preferences.
Build Quality and Certifications
Durability and safety are non-negotiable. Look for units with certifications such as ETL or UL, which indicate rigorous safety testing. High-quality materials and solid construction can prolong the unit’s lifespan and prevent issues like leaks or electrical failures. Balancing initial cost with long-term reliability is key to making a smart purchase.
Frequently Asked Questions
Can I install an electric tankless water heater myself?
While some experienced DIYers may handle basic installations, most units require professional electrical work due to high voltage and wiring complexity. Incorrect installation can lead to safety hazards or voided warranties. Consulting a licensed electrician ensures the unit is installed correctly and safely, especially since electrical upgrades might be necessary.
How do I know if my electrical system can support a tankless water heater?
Assess your existing electrical panel’s capacity, focusing on available amperage and circuit breakers. Many tankless units require dedicated 240V circuits with high amperage ratings. If your panel is outdated or near capacity, you may need a panel upgrade, which adds to the overall cost. It’s wise to have a professional evaluate your electrical system to prevent overloads and ensure proper operation.
Are smart electric tankless water heaters worth the extra cost?
Smart models offer remote control, usage monitoring, and customizable settings, which can enhance convenience and help save energy. If you value remote management or want to integrate the heater into a smart home system, the investment can be justified. However, if simplicity and budget are your priorities, a standard model might serve your needs just as well without the added expense.
What is the typical lifespan of an electric tankless water heater?
Most well-maintained units last around 20 years, which surpasses traditional tank heaters in durability. Regular maintenance, such as flushing out mineral buildup and checking connections, can extend the lifespan. Investing in a high-quality, certified model reduces the risk of early failure and ensures consistent performance over the years.
How much will upgrading my electrical system cost?
The cost varies based on your current setup and the wattage required by your chosen heater. Minor upgrades might range from a few hundred dollars, while extensive electrical panel replacements can exceed a thousand. Consulting with a licensed electrician provides a clearer estimate tailored to your home’s existing infrastructure and the demands of your new water heater.
Conclusion
For most households, the Stiebel Eltron Tempra 29 Plus offers a reliable, high-performance solution making it the best overall pick. Budget-conscious buyers should consider the EcoSmart ECO 11 for its affordability and decent capacity. Tech enthusiasts or those wanting smart home integration will find the Westinghouse WiFi model worth the extra investment. Larger households or those needing higher flow rates will benefit from the EcoSmart ECO 18 or ECOTOUCH 27kW. Beginners or those with limited electrical capacity should prioritize models with lower wattage and easier installation. Ultimately, your choice depends on your household size, budget, and feature preferences—there’s a suitable pick for every need.
