Finding the best tankless water heaters electric involves balancing power, efficiency, and ease of use. The Rheem RTEX-36 stands out as the top overall choice for its high flow rate and smart features, while the EcoSmart ECO 11 offers a budget-friendly, compact solution for smaller households. Larger homes or those with high hot water demands might lean toward models like the WINTEMP 27kW for whole-house capacity. Each option involves tradeoffs—more power means higher upfront costs or complexity, while smaller units may not meet bigger needs. Continue reading for a full breakdown of these options and what makes each one unique.
Key Takeaways
- High wattage models like the WINTEMP 27kW provide ample hot water for larger households, but come with higher installation costs.
- Compact units such as the EcoSmart ECO 11 are ideal for small spaces or single-point applications, though they may struggle with high flow rates.
- Smart features like WiFi control are increasingly common and can enhance convenience but often increase the price.
- Flow rate capacity is a key factor—models with higher GPM ratings suit bigger households or simultaneous uses.
- Price varies widely, and higher-cost units generally offer better durability, capacity, and features, but may not be necessary for smaller needs.
More Details on Our Top Picks
14kW Tankless Electric Water Heater, 240V, On Demand Instant Hot Water with LED Display, ETL Certified, Up to 3.38 GPM
This 14kW model stands out for providing reliable instant hot water for up to 2-3 points of use, making it ideal for small households with moderate demand. Compared with larger units like the WINTEMP 27kW, it offers a more space-friendly size but sacrifices flow rate capacity, which can be limiting for bigger households or simultaneous high-demand points. Its LED display simplifies temperature adjustments, and the high energy efficiency helps reduce ongoing costs. However, it requires a dedicated 240V/60AMP circuit, which might need professional wiring, and its flow rate may not satisfy households with multiple simultaneous showers. This pick makes the most sense for small families or apartments where space and energy efficiency are priorities.Pros:- Compact size fits small spaces easily
- High energy efficiency reduces costs
- LED digital display for easy temperature control
- Advanced safety features ensure reliable operation
Cons:- Requires a 240V/60AMP circuit, possibly needing professional wiring
- Flow rate may be insufficient for multiple large points of use
Best for: Small households or apartments needing reliable, space-efficient hot water for 2-3 points of use
Not ideal for: Larger households or homes with high simultaneous hot water demands, due to limited flow rate
- Power:14kW
- Voltage:240V
- Flow Rate:Up to 3.38 GPM
- Temperature Range:86°F – 140°F
- Dimensions:14.2″ H x 9.5″ L x 3.1″ W
- Certifications:ETL
Bottom line: This model is best suited for small households aiming for space-saving efficiency without high simultaneous demand.
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
The Rheem RTEX-24 offers a notably high flow rate of 5.9 GPM, making it an excellent choice for families needing continuous hot water at multiple points simultaneously. It compares favorably to smaller units like the 11kW Rheem model, which has a more limited flow at 2.68 GPM, making the RTEX-24 more suitable for larger households or homes with multiple bathrooms. Its adjustable digital temperature control ensures precise settings, and its high efficiency minimizes ongoing energy costs. The tradeoff lies in its higher electrical requirements: it demands multiple double pole breakers and sufficient capacity, which can complicate installation. This model is ideal for those who want reliable, high-volume hot water but have the electrical infrastructure to support it.Pros:- High flow rate supports multiple simultaneous points
- Precise digital temperature control
- Energy-efficient operation reduces costs
- Compact size for its capacity
Cons:- Requires multiple double pole breakers and strong electrical capacity
- Higher installation complexity and cost
Best for: Large households or homes with multiple bathrooms requiring continuous hot water
Not ideal for: Small apartments or homes with limited electrical capacity, due to high power demands
- Power Source:Corded Electric
- Wattage:24 KW
- Voltage:240V
- Flow Rate:5.9 GPM
- Maximum Temperature:140°F
- Efficiency:99.8%
Bottom line: This unit is best for large households with ample electrical capacity seeking high-volume, continuous hot water.
110V Tankless Electric Water Heater, 3000W, Instant On-Demand Hot Water with Digital Display
This 110V unit excels in providing instant hot water for small-scale applications such as kitchen sinks, RVs, or camping setups. Its 3000W power output limits flow and temperature rise, making it unsuitable for showers or larger demand points. Compared with the 14kW model, it offers a much lower flow rate but is extremely easy to install in tight spaces. The waterproofing and safety protections add to its appeal for outdoor or mobile use. The main tradeoff is its limited flow—users should not expect to run multiple fixtures simultaneously. It’s an ideal choice for those needing a simple, space-saving solution for low-volume hot water needs.Pros:- Compact, space-saving design
- Easy to install with straightforward wiring
- High thermal efficiency (98%)
- Waterproof and safety protected
Cons:- Limited to low flow applications, not suitable for showers
- Vertical installation only, restricting placement options
- Requires proper wiring and circuit capacity
Best for: RVs, camping, or small kitchens needing instant hot water at low flow rates
Not ideal for: Bathrooms or homes with multiple fixtures requiring higher flow and temperature rise
- Power:3000W
- Voltage:110V
- Temperature Rise:82°F (0.3 GPM) – 131°F (0.5 GPM)
- Waterproof Rating:IPX4
- Material:Stainless steel and ABS
- Installation:Vertical only
Bottom line: This device is perfect for low-demand, space-constrained environments like RVs or small kitchens, not for large household use.
Rheem 11kW 240V Tankless Electric Water Heater
The Rheem 11kW model offers a modest flow rate of 2.68 GPM, suitable for smaller households or single fixtures. It provides on-demand hot water with an easy-to-use digital temperature display and self-modulating technology that adjusts power for efficiency. Compared to the more powerful Rheem RTEX-24, this unit consumes less energy and requires less wiring, making it a simpler, less costly option for moderate use. However, its limited flow rate may struggle during peak demand periods, especially if multiple fixtures run simultaneously. It’s an appealing choice for those with modest hot water needs and limited electrical capacity.Pros:- Affordable and energy-efficient
- Digital temperature control for precision
- Self-modulating technology adapts to demand
- Compact and easy to install
Cons:- Flow rate may be insufficient during peak demand
- Limited capacity for multiple simultaneous fixtures
Best for: Small households or apartments with moderate hot water demand
Not ideal for: Large families or homes with multiple bathrooms needing simultaneous hot water
- Power:11kW
- Voltage:240V
- Flow Rate:up to 2.68 GPM
- Water Connections:1/2″ NPT
Bottom line: This unit is best suited for small households or single-point applications with moderate hot water needs.
WINTEMP 27kW 240V Electric Tankless Water Heater, Whole House On-Demand Instant Hot Water with WiFi Control
The WINTEMP 27kW unit offers the highest flow rate in this lineup at 6.5 GPM, making it suitable for larger homes with multiple simultaneous hot water points. Its high power capacity ensures ample hot water supply, comparable to larger gas models, and its WiFi control adds modern convenience for remote adjustments. This model outshines smaller units like the 14kW and 11kW in capacity, but its installation is more complex, requiring a dedicated 3 x 40 Amp double-pole breaker and precise wiring. Its compact design saves space, yet the high power means it’s best installed by professionals. If you value high capacity and smart home features, this is the most capable choice in the lineup.Pros:- Supports up to 6.5 GPM for whole-house demand
- Energy-efficient self-regulating technology
- WiFi control for remote management
- Compact, space-saving design
Cons:- Requires a dedicated 3 x 40 Amp double-pole breaker
- Installation is complex and may need professional wiring
- Maximum temperature limited to 140°F
Best for: Homes with 2-4 bathrooms needing reliable, high-volume hot water and smart control
Not ideal for: Small apartments or homes with limited electrical capacity, due to high power requirements
- Power:27kW
- Voltage:240V
- Flow Rate:6.5 GPM
- Maximum Temperature:140°F
- Dimensions:11.1″ W x 19.1″ H x 4″ D
- Smart Home Compatibility:Yes
Bottom line: This unit excels for large homes seeking high flow and smart features, provided the electrical setup supports it.
Rheem RTEX-13 240V Residential Tankless Water Heater, Gray
The Rheem RTEX-13 stands out as the most balanced option in this lineup, offering reliable temperature control with its digital LED thermostat and impressive energy efficiency at 99.8%. Compared with the EcoSmart ECO 11, it provides a higher flow rate of 3.17 GPM, making it suitable for small to medium households, but it falls short for larger homes needing more hot water. Its copper heating elements promise durability, yet the 240V requirement and limited flow rate may pose installation challenges for some users. This model excels for those who prioritize precise control and energy savings without the need for a high capacity.
Pros:- Precise temperature control with digital display
- High energy efficiency (99.8%)
- Durable copper heating elements
- Easy to install with standard connections
Cons:- Flow rate may be insufficient for larger households
- Requires 240V power supply, which could complicate installation
Best for: Small to medium households seeking reliable, energy-efficient hot water with easy digital control
Not ideal for: Large families or homes with multiple simultaneous hot water demands, due to its limited flow rate
- Model:RTEX-13
- Voltage:240V
- Flow Rate:up to 3.17 GPM
- Power:13 kW
- Energy Efficiency:99.8%
- Water Connections:1/2 inch NPT and compression fittings
Bottom line: This is an excellent choice for smaller homes that want efficient, controlled hot water without complex installation needs.
36kW Tankless Electric Water Heater 240V, Instant On-Demand, WiFi Control, 8.7 GPM, ETL Certified
The 36kW Tankless Electric Water Heater offers an impressive flow rate of 8.7 GPM, making it ideal for large households or homes with multiple bathrooms. Unlike the Rheem RTEX-13, which is better suited for smaller needs, this model can handle whole-house demand thanks to its high power output and WiFi control, enabling remote temperature adjustments. However, its installation is more complex, requiring multiple 40A breakers and professional setup. The unit’s space-saving design and safety features make it appealing for tech-savvy homeowners who want reliable, on-demand hot water at multiple fixtures simultaneously, though at a higher upfront cost.
Pros:- High flow rate of 8.7 GPM supports whole-house demand
- WiFi control for remote temperature adjustments
- Space-efficient wall-mounted design
- Self-regulating, energy-efficient technology
Cons:- Requires significant electrical infrastructure (multiple 40A breakers)
- Installation complexity and higher initial cost
Best for: Large households or homes needing simultaneous hot water across multiple fixtures with smart remote control
Not ideal for: Small apartments or single-sink setups due to its high power draw and installation complexity
- Power:36 KW
- Voltage:240 V
- Flow Rate:8.7 GPM
- Maximum Temperature:140°F
- Special Features:LED Display, Overheat Protection, WiFi Control
- Dimensions:13.7″ W x 21.1″ H x 5.3″ D
Bottom line: This model is best suited for large households that need high capacity and remote control features, accepting the higher installation effort and cost.
Rheem 18kW 240V Tankless Electric Water Heater, Gray
The Rheem 18kW model offers a middle ground for those needing more capacity than the EcoSmart ECO 11 but not the full power of the 36kW unit. Its 4.4 GPM flow rate makes it suitable for small to medium homes or specific point-of-use applications. The copper heating elements and digital thermostatic control provide durability and precise temperature management. Compared to the 36kW model, it’s less powerful but easier to install, making it appealing for homeowners who want a balance between capacity and ease of setup. However, for large households with high simultaneous demand, it might fall short.
Pros:- Compact, space-saving design
- Self-modulating technology for energy efficiency
- Durable copper heating elements
- Digital temperature control with LED display
Cons:- Limited flow rate for large households
- Requires professional installation
Best for: Mid-sized homes or point-of-use setups where space and ease of installation are priorities
Not ideal for: Large households or multiple fixtures running simultaneously, due to its limited flow rate
- Wattage:18 kW
- Voltage:240V
- Flow Rate:4.4 GPM
- Maximum Temperature:140°F
- Efficiency:99.8%
- Maximum Pressure:150 psi
Bottom line: This heater is well-suited for homes needing reliable hot water at moderate flow rates with simpler installation requirements.
EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240V
The EcoSmart ECO 11 prioritizes space savings and energy efficiency, making it ideal for small sinks, bathrooms, or low-flow applications. Its 13 kW power rating and self-modulating technology allow it to produce hot water reliably within a narrow flow range of 1.3 to 3.1 GPM, but this limits its capacity to support multiple fixtures simultaneously. Compared to the Rheem RTEX-13, it’s more compact and easier to install in tight spaces, yet it might struggle in larger households or high-demand situations. This model makes sense for single-point use where space and energy savings matter most.
Pros:- Compact, wall-mountable design
- Energy-efficient self-modulating technology
- Provides consistent temperature control within 1 degree
- Easy to install in small spaces
Cons:- Limited flow rate, unsuitable for multiple fixtures
- Electrical setup requires 54 A circuit, which may need professional wiring
Best for: Low-flow, point-of-use applications such as small sinks or bathrooms
Not ideal for: Large households or multiple fixtures simultaneously, due to its limited flow capacity
- Power:13 kW
- Voltage:240 V
- Flow Rate:1.3 to 3.1 GPM
- Temperature Range:80-140°F
- Efficiency:99%
- Dimensions:11.5 x 8 x 3.75 inches
Bottom line: This unit is ideal for tight spaces needing reliable, on-demand hot water at low flow rates, but not for whole-house solutions.
How We Picked
To determine the best electric tankless water heaters, I evaluated each model based on performance, build quality, ease of installation, and value for money. Key factors included flow rate capacity, power consumption, and available features such as digital displays or WiFi controls. I also considered user safety certifications, durability, and how well each model suited different household sizes and hot water demands. The ranking reflects a balance of these elements, prioritizing models that deliver reliable, efficient hot water without unnecessary complexity or cost.Factors to Consider When Choosing Best Tankless Water Heaters Electric
Choosing the right electric tankless water heater requires understanding several critical factors. It’s important to match a unit’s capacity with your household’s hot water needs, but also consider installation complexity, energy efficiency, and long-term costs. A model with too low a flow rate won’t meet your demand, while overly powerful units can be cost-prohibitive and inefficient for smaller households. Additionally, features like WiFi controls and digital displays can improve usability but add to the purchase price. This guide highlights key points to help you make an informed choice beyond just comparing specs.Flow Rate and Power Capacity
Flow rate, measured in GPM, is the most direct indicator of how much hot water a unit can supply at once. Larger households or simultaneous fixtures require higher GPM ratings—models like the WINTEMP 27kW offer around 8.7 GPM, suitable for multiple outlets. Power capacity, typically rated in kilowatts (kW), determines how quickly a unit heats water; higher wattage units can handle more demanding households but may require special electrical wiring. Matching capacity to your household size is essential to avoid undersupply or overpaying for unnecessary power.
Installation Requirements
Proper installation is critical and can influence overall costs and convenience. Some models, especially higher wattage units like the WINTEMP 27kW, need dedicated 240V circuits and potentially professional wiring. Smaller units such as the EcoSmart ECO 11 are more straightforward to install and may fit into existing electrical setups, making them suitable for DIY installation. Always check your home’s electrical capacity and consult a professional if unsure, as incorrect wiring can lead to safety hazards or reduced lifespan of the unit.
Energy Efficiency and Operating Costs
Most tankless electric water heaters are highly efficient because they heat water on demand, reducing standby losses. However, the actual operating costs depend on wattage and household usage. Units with smart features or variable power settings can optimize energy use, saving money over time. For example, models like the Rheem RTEX series offer adjustable temperature controls, allowing you to balance comfort and efficiency. Consider your typical hot water demand and local electricity rates to select a unit that minimizes long-term expenses.
Features and Usability
Additional features such as digital displays, WiFi connectivity, and multiple heating modes enhance user experience. WiFi-enabled models like the WINTEMP 27kW provide remote control and diagnostic capabilities, which can prevent outages and simplify maintenance. Digital displays help set precise temperatures, avoiding scalding or energy waste. However, these extras often come with higher initial costs and potential complexity. Prioritize features that align with your comfort level and budget, ensuring they add real value to your household’s hot water management.
Price and Value
Prices for electric tankless water heaters vary significantly based on capacity, features, and brand reputation. Budget options like the EcoSmart ECO 11 deliver excellent value for small-scale or occasional use but may fall short in high-demand scenarios. Mid-range units such as the Rheem RTEX series balance cost with performance, suitable for most typical households. Premium models with advanced features or higher capacity tend to cost more upfront but can provide better durability and efficiency over time. Consider your specific needs and long-term savings potential when choosing between entry-level and premium options.
Frequently Asked Questions
Can I install an electric tankless water heater myself?
While some small units like the EcoSmart ECO 11 are designed for DIY installation, larger or high-capacity models often require professional electrical work due to their power demands. If you have experience with electrical wiring and plumbing, you might manage the installation yourself, but for safety and compliance reasons, hiring a licensed electrician is recommended. Proper installation ensures the unit operates efficiently and reduces the risk of electrical hazards or water damage. Always review the manufacturer’s instructions and local codes before proceeding.
Will a tankless electric water heater be enough for a large household?
High-capacity models like the WINTEMP 27kW or the 36kW units are designed to meet the demands of larger households, providing multiple outlets simultaneously. However, these require substantial electrical infrastructure and often professional installation. For smaller households or single-point applications, lower wattage units are sufficient and more cost-effective. Assess your peak hot water usage to select a model with an appropriate flow rate, avoiding undersupply during busy times or overpaying for unnecessary capacity.
What are the main advantages of WiFi-enabled water heaters?
WiFi-enabled models offer remote control and monitoring, allowing you to adjust temperatures, run diagnostics, or troubleshoot issues from your smartphone. This convenience can prevent hot water outages and help optimize energy use, potentially lowering utility bills. However, they tend to be pricier and may require ongoing updates or subscriptions. For tech-savvy homeowners or those seeking added control, these features add value, but they might be unnecessary if you prefer simple operation.
How long does a typical electric tankless water heater last?
With proper maintenance, most electric tankless water heaters can operate for 20 years or more. Regular descaling, especially in areas with hard water, and checking electrical connections help extend their lifespan. Investing in a high-quality, reputable brand often results in better durability and support. Keep in mind that the longevity of the unit also depends on proper installation and usage, so selecting a model suited to your household’s demands is key to maximizing its lifespan.
Are more expensive models worth the extra cost?
Higher-priced units often offer increased capacity, better build quality, and advanced features like WiFi control or multiple heating modes, which can justify the investment for larger households or tech enthusiasts. They typically demonstrate higher durability and energy efficiency, leading to savings over their lifespan. However, if your hot water needs are modest, a budget-friendly model may suffice and provide excellent value. Carefully evaluate your household’s demands and long-term goals before opting for a premium unit.
Conclusion
For most households, the Rheem RTEX-36 strikes the best balance of capacity, features, and reliability, making it the ideal overall choice. Budget-conscious buyers or those with smaller needs will find the EcoSmart ECO 11 to be an excellent value pick. Homeowners seeking maximum performance and smart features should consider the WINTEMP 27kW or larger models, which excel in capacity and connectivity. New users or those installing in existing homes should prioritize units that are easier to set up, while larger families or high-demand users should opt for higher wattage, high flow rate options. Tailor your choice to your household size, budget, and desired features for the best results.
