If you’re searching for the best tankless water heaters electric, you’re looking for a solution that delivers hot water on demand while saving space and energy. The 18kW Electric Tankless Water Heater stands out as the overall top choice for its balanced performance and smart features. For those on a budget, the Rheem RTEX-13 offers reliable hot water at a lower cost, though it has limited flow capacity. Meanwhile, the Stiebel Eltron Tempra 24 Trend makes sense for users needing higher flow rates and durability. Keep in mind, tradeoffs often involve flow rates, installation complexity, and upfront costs. Continue reading for a detailed breakdown of each model and what suits your specific needs best.
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Key Takeaways
- Top models balance flow rate, energy efficiency, and ease of installation, with higher wattage units generally providing more hot water.
- WiFi connectivity is increasingly common, offering remote control and monitoring, but adds to the cost and complexity.
- Flow rate capacity varies significantly, making it crucial to match the heater to your household’s hot water demand.
- Price often correlates with features and build quality—more expensive models tend to last longer and offer better performance.
- Size and installation requirements differ; compact models are ideal for small spaces but may have limited flow capacity.
| tankless water heaters electric | Voltage | Flow Rate | Maximum Temperature | Power |
|---|---|---|---|---|
| 18kW Electric Tankless Water H | 240 volts | 4.3 gpm | 140 °F | — |
| 14kW Tankless Electric Water H | 240 volts | 3.38 GPM | 140 °F | — |
| Westinghouse Tankless Water He | 240V | 2.6–4.2 GPM | — | 18kW |
| Westinghouse 14kW Tankless Ele | 240V | 3.4 GPM | 140°F | 14 KW |
| Rheem 240V Tankless Electric W | 240 volts | up to 3.17 GPM | 140 °F | — |
| 18kW Tankless Water Heater Ele | 240V | 4.9 GPM | 140°F | 18 kW |
| Rheem RTEX-27 240V Tankless Wa | 240V | — | — | — |
| Electrolux 14kW WiFi Tankless | 240V | 3.4 GPM | 140°F | 14 kW |
| 14kW Tankless Electric Water H | 240V | 3.3 GPM | 131°F | 14 KW |
| Stiebel Eltron Tempra 24 Trend | 240V | — | — | 24 kW |
| 110V Tankless Electric Water H | 110 volts | 0.45 gpm | 131 °F | — |
| 27kW Tankless Water Heater Ele | 240 volts | 7.4 GPM | 140°F | 27 kW |
More Details on Our Top Picks
18kW Electric Tankless Water Heater 240V WiFi Certified
This model stands out as the best overall due to its combination of high efficiency, WiFi connectivity, and space-saving design. Compared with the Westinghouse 18kW unit, it offers similar power but adds remote control features, making it ideal for tech-savvy homeowners who value convenience. The self-modulating technology ensures energy savings, although it requires a robust electrical setup—professional installation is essential. Its flow rate of 4.3 GPM suits smaller households, but larger families may find it insufficient. The LED display and safety protections add to its appeal, but the need for specific electrical wiring can be a barrier for some. Overall, this pick makes the most sense for homes with 2-3 bathrooms seeking smart, efficient hot water.
Pros:- Provides continuous hot water with self-modulating efficiency
- WiFi control for remote temperature adjustment
- Space-saving wall-mounted design
- Safety features including overheat protection
Cons:- Requires professional installation and specific electrical setup
- Limited flow rate for larger households
Best for: Homeowners wanting a high-efficiency, WiFi-enabled unit for 2-3 bathrooms
Not ideal for: Larger households or homes requiring high flow rates, due to its 4.3 GPM limit
- Power Source:AC
- Wattage:18,000 watts
- Voltage:240 volts
- Flow Rate:4.3 gpm
- Maximum Temperature:140 °F
- Efficiency:High Efficiency
Our verdict“Ideal for small to medium homes seeking smart, energy-efficient hot water with minimal footprint.”
14kW Tankless Electric Water Heater, On Demand, 240V, 3.38 GPM
This 14kW model is well-suited for small households or single-point use, offering instant hot water with a flow rate of 3.38 GPM. Unlike the Westinghouse 14kW unit, it emphasizes a highly compact form factor, making it perfect for tight spaces or under-sink installations. Its advanced safety protections and LED temperature control provide precision and security, but it demands a dedicated 60A circuit and proper wiring—factors that could complicate DIY setups. Its lower flow rate limits its suitability for simultaneous multiple fixtures, but it excels at providing reliable hot water precisely where needed. This makes it a great choice for apartment dwellers or single-bathroom homes where space and efficiency are priorities.
Pros:- Compact size fits small spaces easily
- Provides instant hot water with high efficiency
- Advanced safety features including leakage and over-temperature protection
- Precise temperature control via LED display
Cons:- Requires dedicated 60A circuit and professional wiring
- Limited flow rate may restrict simultaneous use
Best for: Apartment residents or single-bathroom homes needing point-of-use hot water
Not ideal for: Large households or multi-point simultaneous use, due to its limited flow rate
- Power Source:Hard Wiring Required
- Wattage:14 KW
- Voltage:240 volts
- Maximum Temperature:140 °F
- Flow Rate:3.38 GPM
- Material Type:Metal
Our verdict“Best for small-scale applications where space savings and precise control are essential.”
Westinghouse Tankless Water Heater Electric 18kW 240V Wi-Fi Whole House Use
The Westinghouse 18kW model offers a balance of power and smart home integration, with a flow rate of up to 4.2 GPM suitable for whole-house use. Compared with the 14kW Westinghouse 14kW unit, this higher wattage provides more capacity for simultaneous fixtures, making it better suited for larger households. Its Wi-Fi control and compatibility with Alexa and Google Home add convenience, though installation may be complex for those unfamiliar with electrical wiring—requiring a 75A breaker and professional setup. Its safety features and ETL certification add peace of mind. While it’s slightly bulkier than smaller models, this unit makes sense for families needing reliable, on-demand hot water for multiple points at once.
Pros:- Supports multiple water points simultaneously
- Fast hot water delivery within seconds
- Wi-Fi app control with voice assistant compatibility
- ETL safety certification
Cons:- Requires a substantial electrical setup (75A breaker)
- Installation complexity may deter DIYers
Best for: Families requiring reliable, whole-house hot water with smart control
Not ideal for: Small apartments or single-point use, where a compact unit is more appropriate
- Power:18kW
- Voltage:240V
- Flow Rate:2.6–4.2 GPM
- Temperature Range:86–140°F
- Dimensions:18.7 x 3.94 x 14.17 inches
- Installation Requirements:75A / 0.5–4.2 GPM / 3/4″ NPT
Our verdict“A strong choice for larger households seeking dependable, smart-controlled hot water across the home.”
Westinghouse 14kW Tankless Electric Water Heater, 240V, WiFi, ETL Certified, Gray
This 14kW Westinghouse unit emphasizes smart control and space efficiency, with a flow rate of 3.4 GPM suitable for small to medium homes. It shares similar features with the 18kW model but offers slightly lower power, making it ideal for homes with modest hot water demands. Its Wi-Fi connectivity and voice control compatibility make it convenient, yet installation can be tricky, requiring a dedicated 60A breaker. Compared to the Rheem RTEX-13, it provides a higher flow rate, but the latter’s simpler digital thermostat might appeal more to DIYers. This model suits those who want reliable, on-demand hot water with advanced control features in a compact package.
Pros:- Supports multiple water points simultaneously
- Smart WiFi and voice control features
- Compact, wall-mountable design
- ETL safety certification
Cons:- Requires dedicated 60A breaker and professional wiring
- Limited to residential use with moderate flow needs
Best for: Small to medium-sized homes needing smart hot water with space efficiency
Not ideal for: Large households or high-demand applications, due to flow rate constraints
- Power:14 KW
- Voltage:240V
- Flow Rate:3.4 GPM
- Maximum Temperature:140°F
- Certifications:ETL
Our verdict“Great for homes that value smart features and space savings over high flow capacity.”
Rheem 240V Tankless Electric Water Heater RTEX-13
The Rheem RTEX-13 offers a dependable, energy-efficient solution for single-point applications or small households, with a flow rate of up to 3.17 GPM. Its high energy efficiency—at least 99.8%—makes it an appealing choice for those focused on lower utility bills. Compared with the more advanced Wi-Fi options like the Westinghouse models, it lacks smart connectivity but compensates with straightforward operation and durable copper heating elements that are field serviceable. The unit’s compact design and adjustable digital thermostat provide good control, but its limited capacity restricts larger household use. It’s an excellent pick for budget-minded consumers prioritizing efficiency and simplicity over smart features.
Pros:- High energy efficiency at 99.8%
- Adjustable digital thermostat with LED display
- Durable copper heating elements, field serviceable
- Compact wall-mounted design
Cons:- Flow rate may be insufficient for larger households
- Requires professional installation due to 240V wiring
Best for: Single-point use or small households seeking a reliable, cost-effective hot water solution
Not ideal for: Multi-bathroom homes or simultaneous fixtures, due to flow rate limitations
- Power Source:Electric
- Wattage:13 KW
- Voltage:240 volts
- Flow Rate:up to 3.17 GPM
- Maximum Temperature:140 °F
- Material Type:Copper
Our verdict“Suitable for budget-conscious buyers who need a reliable, small-scale hot water heater without smart features.”
18kW Tankless Water Heater Electric, NOVIEEX 240V 3s Instant Hot Water Heater
This NOVIEEX 18kW model stands out for its impressive flow rate of 4.9 GPM, making it well-suited for households that need hot water at multiple fixtures simultaneously. Compared to smaller units like the Electrolux 14kW, it offers higher capacity, which is ideal for small apartments or garages. However, its high power requirement and indoor-only design mean it may not suit every home’s electrical system or outdoor installations. The compact, wall-mounted form factor makes it easy to install in tight spaces, but professional electrical work is a must because of its demanding 240V circuit needs. Its efficiency of 99.8% helps reduce running costs, making it a practical choice for those prioritizing capacity and space savings.
Pros:- High 4.9 GPM flow rate supports multiple fixtures simultaneously
- Compact, space-saving wall-mounted design
- Energy-efficient with 99.8% thermal efficiency
Cons:- Requires professional installation and specific electrical capacity
- Limited to indoor use only
- Higher power demand may not be compatible with older electrical systems
Best for: Small to medium-sized households needing reliable, high-capacity hot water in limited spaces
Not ideal for: Homes with outdated electrical systems or where outdoor installation is necessary
- Power:18 kW
- Voltage:240V
- Flow Rate:4.9 GPM
- Maximum Temperature:140°F
- Dimensions:11.14″ W x 15.86″ H x 3.18″ D
- Water Connections:3/4″ NPT
- Material:Metal
- Warranty:1 year
Our verdict“This model is ideal for small households that need high output and have suitable electrical infrastructure.”
Rheem RTEX-27 240V Tankless Water Heater
The Rheem RTEX-27 offers a solid balance of features with its digital thermostat and self-modulation technology, which adjusts power based on demand. Compared to the Stiebel Eltron Tempra 24 Trend, it provides more straightforward installation with its bottom water connections and is tailored for households that value precise temperature control. Its three heating chambers are suitable for typical family needs but may fall short in very high-demand situations. The digital LED display enhances user experience, but the unit’s capacity is limited compared to larger models like the NOVIEEX 18kW, making it less suitable for simultaneous multiple fixtures. Nonetheless, its durable copper heating elements and energy modulation make it a reliable mid-range choice.
Pros:- Digital thermostat with precise temperature control
- Self-modulating for energy efficiency
- Durable copper heating elements
Cons:- Requires professional installation
- Limited to 3 heating chambers, possibly affecting capacity in high-demand scenarios
Best for: Families seeking reliable, adjustable hot water with simple installation
Not ideal for: Large households or those with very high hot water demands requiring multiple simultaneous fixtures
- Voltage:240V
- Heating Chambers:3
- Temperature Control:Digital with LED display
- Water Connection:3/4 inch NPT
Our verdict“Ideal for families needing consistent, adjustable hot water with straightforward setup.”
Electrolux 14kW WiFi Tankless Electric Water Heater, 240V, 3.4 GPM
This Electrolux 14kW unit excels in delivering instant hot water for 1-2 fixtures, making it perfect for small households or dedicated point-of-use applications. Its smart WiFi and Alexa compatibility stand out, offering remote control and monitoring—features not found on most competitors like the Rheem RTEX-27. Its space-saving design makes it ideal for under-sink or small wall-mounted setups, but the 3.4 GPM flow rate limits its usefulness for larger families or multiple simultaneous fixtures. Like other high-efficiency models, it requires a 240V, 60A breaker, so ensuring your home wiring can support it is essential. For tech-savvy users prioritizing convenience and quick hot water, this model makes a compelling choice despite its limited capacity.
Pros:- Instant hot water in 3 seconds
- WiFi and Alexa compatibility for remote control
- Space-efficient and easy to install
Cons:- Limited to 3.4 GPM, suitable only for 1-2 fixtures
- Requires professional wiring and a 60A breaker
Best for: Single fixtures or small households seeking remote control and smart features
Not ideal for: Larger homes or multiple fixtures requiring higher flow rates
- Power:14 kW
- Voltage:240V
- Flow Rate:3.4 GPM
- Maximum Temperature:140°F
- Material:Copper
- Dimensions:8.9″W x 12.8″H
- Weight:7.8 pounds
Our verdict“A smart, compact choice for small spaces with high-tech demands and limited hot water needs.”
14kW Tankless Electric Water Heater 240V for Sink & Shower, Gray
This 14kW model is tailored for single or dual fixture setups, such as under-sink or small bathroom applications. Its quick 3-second heating ensures instant hot water, comparable to the Electrolux but with slightly more straightforward installation requirements. The 99.8% thermal efficiency and safety features like leakage and overheat protection make it a reliable choice for space-constrained installations. Compared to larger units like the NOVIEEX 18kW, it sacrifices capacity for compactness and ease of wiring, requiring a 60A breaker. It’s perfect for those who need a dedicated, point-of-use heater but won’t meet the demands of larger households or multiple simultaneous fixtures.
Pros:- Instant hot water with 3-second heating
- High thermal efficiency of 99.8%
- Safety features including leakage and overheating protection
Cons:- Requires a 60A circuit breaker
- Limited to 1-2 fixtures, not suitable for whole-house use
Best for: Single fixture or small point-of-use applications with space constraints
Not ideal for: Multiple fixtures or whole-house hot water needs
- Power:14 KW
- Voltage:240V
- Flow Rate:3.3 GPM
- Maximum Temperature:131°F
- Dimensions:12.2″ W x 17.25″ H
- Material:Aluminum, Brass, Metal
Our verdict“Best for targeted, point-of-use hot water needs where space and wiring are limited.”
Stiebel Eltron Tempra 24 Trend Electric Tankless Water Heater, 24kW, 240V
The Tempra 24 Trend makes a strong case for whole-house applications, with its 24kW power output capable of supporting multiple showers and fixtures in cooler climates, especially when paired with a 150 A service. Its auto-modulation technology adjusts power dynamically, maintaining consistent water temperature and reducing energy waste. Compared to the Rheem RTEX-27, it offers a more robust solution for larger households but requires substantial electrical infrastructure, making installation more complex. Its digital temperature control and silent operation present a user-friendly experience, though the high amperage requirement limits compatibility for some homes. For those with the appropriate electrical capacity, this model provides reliable, continuous hot water for the entire household.
Pros:- Provides continuous on-demand hot water
- Space-efficient and energy-smart design
- Digital temperature display for precise control
Cons:- Requires a high 150 A electrical service
- Installation can be complex and costly
Best for: Larger households or homes in colder climates needing continuous, high-volume hot water
Not ideal for: Small homes or apartments with limited electrical capacity
- Power:24 kW
- Voltage:240V
- Recommended Service:150 A
- Output Temperature Range:68°F to 140°F
Our verdict“Ideal for large households with sufficient electrical infrastructure seeking reliable, whole-house hot water.”
110V Tankless Electric Water Heater, 3000W Instant Under Sink Hot Water Heater with Digital Display
This model stands out for its compact size and straightforward installation, making it ideal for small spaces like under-sink applications or outdoor setups. Unlike larger units such as the NOVIEEX 27kW, it offers instant hot water with impressive energy efficiency, but its limited flow rate of 0.45 GPM means it can’t support multiple outlets simultaneously. Compared with high-capacity options, this heater is less suitable for whole-house demands, but it excels in providing precise temperature control in a single outlet scenario. Its safety features, including waterproof and overheat protections, add peace of mind. The main tradeoff is its low flow rate, which restricts use to low-demand situations, making it less versatile for larger households or multiple fixtures running at once.
Pros:- Instant heating with precise temperature control
- Space-saving wall-mounted design
- High energy efficiency with 98% thermal efficiency
- Comprehensive safety features including waterproof and overheat protection
Cons:- Not suitable for shower use due to low flow rate
- Minimum flow required is 1.8 GPM, limiting applications
Best for: Single sink or outdoor use where space is tight and demand is low
Not ideal for: Whole-house hot water needs or multiple simultaneous outlets
- Power Source:AC
- Wattage:3000 watts
- Voltage:110 volts
- Flow Rate:0.45 gpm
- Maximum Temperature:131 °F
- Heat Output:3000 watts
- Mount Type:Wall
- Item Dimensions:4.5″W x 7.7″H
- Item Weight:2.4 pounds
Our verdict“This heater makes the most sense for individuals needing a compact, energy-efficient solution for low-demand applications like under-sink or outdoor use.”
27kW Tankless Water Heater Electric, NOVIEEX 240V 3s Instant Hot Water Heater, 7.4 GPM Flow Rate, Indoor Use
The NOVIEEX 27kW model makes a clear statement with its high power output, supporting whole-house hot water needs with a flow rate of 7.4 GPM. Compared to smaller units like the 14kW models, this heater can handle multiple fixtures simultaneously without sacrificing temperature stability, but it requires professional installation due to its 27kW power draw and size. Its precise temperature control, adjustable from 77°F to 140°F, offers flexibility for various household needs, and the nearly perfect energy conversion rate of 99.8% minimizes energy waste. While the upfront cost and installation complexity are higher, its reliability and capacity justify the investment for larger households or demanding applications. The main tradeoff is the need for a dedicated 240V circuit and sufficient space for installation.
Pros:- High power output suitable for whole-house use
- Precise temperature control with LED display
- Energy-efficient with 99.8% conversion rate
- Advanced safety features and reliable performance
Cons:- Requires professional electrical installation
- Large size may not fit in very small spaces
- Higher upfront cost compared to smaller units
Best for: Large households or households with multiple simultaneous hot water demands
Not ideal for: Small apartments or spaces with limited electrical capacity
- Power:27 kW
- Voltage:240 volts
- Flow Rate:7.4 GPM
- Maximum Temperature:140°F
- Dimensions:14.13″ W x 15.86″ H x 3.18″ D
- Water Connection:3/4″ NPT
- Mount Type:Wall
Our verdict“This heater is ideal for households needing reliable, high-capacity hot water, provided space and electrical capacity are available.”
How We Picked
Products were selected based on a combination of performance metrics, user reviews, build quality, and feature sets. Flow rate, wattage, and compatibility with household demand played key roles in ranking, ensuring each model meets different user needs. We also prioritized models with good energy efficiency, durability, and ease of installation, while considering value for money. The goal was to identify options suitable for a range of budgets and household sizes, from small apartments to larger homes, highlighting the best balance of cost and performance.Factors to Consider When Choosing Best Tankless Water Heaters Electric
Choosing the right electric tankless water heater involves evaluating several factors to ensure it meets your household’s hot water needs efficiently. Understanding these key considerations can help you avoid common pitfalls and select a model that offers long-term value and reliability.Flow Rate and Household Demand
Matching the heater’s flow rate with your household’s hot water demand is essential. If you have multiple bathrooms or high simultaneous usage, look for units with higher GPM ratings—typically 3-4 GPM for small homes and 7+ GPM for larger households. Selecting a unit with too low a flow rate can result in cold water during peak usage, while overspending on a high-capacity model for a small space may be unnecessary.
Wattage and Power Requirements
Wattage determines how quickly a heater can produce hot water. Higher wattage units, like 27kW models, provide faster heating and higher flow rates but often require dedicated circuits and professional installation. Lower wattage models are easier to install but might struggle with larger demands. Always ensure your home’s electrical system can support the unit’s power requirements.
Energy Efficiency and Operating Costs
While electric tankless heaters are generally efficient, features like advanced sensors and WiFi controls can optimize energy use further. Keep an eye on energy consumption ratings and consider models with smart features that adjust output based on demand. Investing in a slightly more efficient model can lead to substantial savings over its lifespan, especially if you plan to run it frequently.
Installation Space and Complexity
Size and ease of installation vary across models. Compact units are ideal for small spaces or retrofit projects, but may have limited flow capacity. Larger, more powerful units might require professional wiring and mounting considerations. Carefully assess your available space and whether you need a simple plug-in model or a more involved setup.
Price and Long-Term Value
Pricing ranges widely, reflecting differences in wattage, features, and build quality. Cheaper models may suffice for small or infrequent use but could lack durability or capacity. Premium options often include better materials, longer warranties, and smart features, making them a better investment for demanding or long-term use. Balance your budget with the expected lifespan and performance benefits.
Frequently Asked Questions
Can I install an electric tankless water heater myself?
While some small, plug-in models are suitable for DIY installation, most electric tankless water heaters require professional wiring due to high power demands and safety considerations. Incorrect installation can lead to electrical hazards or reduced performance. Consulting a licensed electrician ensures the unit is installed safely and meets local electrical codes, especially for models over 3kW.
How does flow rate impact the performance of a tankless water heater?
Flow rate directly affects how much hot water the unit can supply simultaneously. If the demand exceeds the heater’s capacity, you may experience cold water during peak usage. To avoid this, measure your household’s simultaneous hot water needs and select a unit with a flow rate that comfortably exceeds that demand. This ensures consistent hot water without interruption.
Are WiFi-enabled electric tankless heaters worth the extra cost?
WiFi features add convenience by allowing remote control, monitoring, and scheduling, which can improve energy efficiency. However, they also increase the initial price and may introduce complexity in setup. If you value remote management or plan to integrate your heater into a smart home system, investing in a WiFi-capable model makes sense; otherwise, simpler units may suffice.
What is the typical lifespan of an electric tankless water heater?
Most high-quality electric tankless heaters last between 20 and 25 years with proper maintenance. Durability depends on factors like build quality, usage patterns, and installation conditions. Regular flushing to prevent mineral buildup and timely component replacements can extend the lifespan, making them a worthwhile long-term investment.
What should I consider if I want to upgrade from a traditional tank heater?
Switching to a tankless model can save space and reduce energy costs, but it requires considering your household’s hot water demand and electrical capacity. Upgrading may involve electrical panel upgrades or dedicated circuits. Evaluating your peak usage and ensuring your home’s wiring can support higher wattage units are crucial steps to a successful transition.
Conclusion
For most homes, the overall best choice is the 18kW Electric Tankless Water Heater with WiFi, offering a good balance of capacity, smart features, and reliability. Budget-conscious buyers will find the Rheem RTEX-13 provides dependable performance at a lower price point, though with limited flow. Those seeking higher flow rates and durability might prefer the Stiebel Eltron Tempra 24 Trend. Beginners or small households should consider models with simpler installation, like plug-in units, while larger households or demanding applications justify investing in premium, high-capacity systems. Ultimately, matching the unit’s specs to your specific hot water needs ensures satisfaction and long-term savings.
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