Finding an electric tankless water heater suitable for a small house involves balancing power, size, and cost. The 27kW Tankless Water Heater Electric 240V WiFi stands out as the overall best, offering high capacity and smart features. For those with simpler needs, the 14kW Tankless Electric Water Heater 240V for Sink & Shower provides reliable performance at a lower price. The main tradeoffs include balancing capacity with energy efficiency and installation complexity. Continue reading for a detailed comparison to help you pick the right model for your small home.
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Key Takeaways
- Higher wattage models deliver more hot water but may require more robust electrical wiring, increasing installation complexity.
- WiFi-enabled models add convenience but often come at a premium, suitable for tech-savvy users.
- Compact units are easier to install in small spaces but may have limited flow rates, so match capacity to your household size.
- Price varies significantly; the best value combines reliable performance with affordable features.
- Pay attention to certifications like ETL or UL to ensure safety and compliance for small house installations.
| 27kW Tankless Water Heater Electric 240V WiFi, ETL Certified |  | Best Overall for High Demand Small Homes | Power Source: Electric/AC | Wattage: 27,000 watts | Voltage: 240 volts | VIEW ON AMAZON | See Our Full Breakdown |
| 14kW Tankless Electric Water Heater 240V for Sink & Shower, Gray |  | Best Value for Single or Dual Point Hot Water | Power: 14kW | Voltage: 240V | Dimensions: 15.87″ x 11.14″ x 2.87″ | VIEW ON AMAZON | See Our Full Breakdown |
| Westinghouse 14kW Tankless Electric Water Heater, 240V, WiFi, Gray |  | Best for Smart Home Integration in Small Spaces | Power Source: Hard Wiring | Wattage: 14 KW | Voltage: 240V | VIEW ON AMAZON | See Our Full Breakdown |
| Rheem 11kW Multi Fixture Tankless Electric Water Heater – 240V |  | Best for Budget-Conscious Small Households | Power: 11kW | Voltage: 240V | Flow Rate: 2.68 GPM | VIEW ON AMAZON | See Our Full Breakdown |
| 18kW Electric Tankless Water Heater 240V WiFi Certified |  | Best for Moderate Hot Water Needs with Space Constraints | Power: 18,000 watts | Voltage: 240 volts | Flow Rate: 4.3 gpm | VIEW ON AMAZON | See Our Full Breakdown |
| ThermoMate 18kW Electric Tankless Water Heater, On Demand Instant Hot Water, 240V |  | Best Overall for Whole-House Efficiency | Power: 18kW | Voltage: 240V | Flow Rate: Up to 4.4 GPM | VIEW ON AMAZON | See Our Full Breakdown |
| 14kW Tankless Electric Water Heater ORBEK On Demand 240V 3.38 GPM |  | Best Value for Limited Hot Water Needs | Power: 14kW | Voltage: 240V | Flow Rate: 3.38 GPM | VIEW ON AMAZON | See Our Full Breakdown |
| 18kW Tankless Electric Water Heater 240V for Whole House, Gray |  | Best for Whole-House Use in Small Homes | Power: 18kW | Voltage: 240V | Dimensions: 15.87″ x 11.14″ x 2.87″ | VIEW ON AMAZON | See Our Full Breakdown |
| Rheem RTEX-24 24kW 240V Electric Tankless Water Heater |  | Best for High Flow and Compact Size | Power: 24kW | Voltage: 240V | Flow Rate: Up to 5.9 GPM | VIEW ON AMAZON | See Our Full Breakdown |
| Rheem 18kW 240V Tankless Electric Water Heater, Gray |  | Best Durable Option with Self-Modulation | Power: 18kW | Voltage: 240V | Flow Rate: Up to 4.4 GPM | VIEW ON AMAZON | See Our Full Breakdown |
| electric tankless water heater for small house | Voltage | Flow Rate | Power | Temperature Range |
|---|---|---|---|---|
| 27kW Tankless Water Heater Ele | 240 volts | 6.5 gpm | — | — |
| 14kW Tankless Electric Water H | 240V | — | 14kW | 86°F to 131°F |
| Westinghouse 14kW Tankless Ele | 240V | 3.4 GPM | — | — |
| Rheem 11kW Multi Fixture Tankl | 240V | 2.68 GPM | 11kW | 80°F – 140°F |
| 18kW Electric Tankless Water H | 240 volts | 4.3 gpm | 18,000 watts | — |
| ThermoMate 18kW Electric Tankl | 240V | Up to 4.4 GPM | 18kW | — |
| 14kW Tankless Electric Water H | 240V | 3.38 GPM | 14kW | 86°F to 140°F |
| 18kW Tankless Electric Water H | 240V | — | 18kW | 86°F to 131°F |
| Rheem RTEX-24 24kW 240V Electr | 240V | Up to 5.9 GPM | 24kW | 80°F – 140°F |
| Rheem 18kW 240V Tankless Elect | 240V | Up to 4.4 GPM | 18kW | — |
More Details on Our Top Picks
27kW Tankless Water Heater Electric 240V WiFi, ETL Certified
This 27kW unit stands out for its impressive flow rate of 6.5 GPM, making it suitable for small homes with multiple hot water points. Unlike the smaller Westinghouse 14kW model, it can handle higher simultaneous demands, but it requires a robust electrical setup and professional installation. Its smart WiFi control offers convenient remote management, yet compatibility issues may arise with certain smart home systems. The compact, wall-mounted design saves space, and the self-modulating technology enhances energy efficiency. However, its higher power draw and installation complexity are drawbacks for DIYers or homes with limited electrical capacity.
Pros:- High flow rate of 6.5 GPM supports multiple fixtures simultaneously
- Smart WiFi control allows remote adjustments and monitoring
- Space-efficient wall-mounted design conserves space
- Energy-efficient self-modulating technology reduces power use
Cons:- Requires professional installation and specialized electrical setup
- Limited capacity for larger households or very high demand
- Compatibility issues with some smart home systems
Best for: Small households needing multiple hot water points with high flow demands and smart control integration
Not ideal for: Homes with limited electrical capacity or those seeking simple, plug-and-play solutions
- Power Source:Electric/AC
- Wattage:27,000 watts
- Voltage:240 volts
- Flow Rate:6.5 gpm
- Maximum Temperature:140 °F
- Item Dimensions:13″ W x 15.9″ H
- Item Weight:21.5 pounds
- Warranty:2-year limited
Our verdict“This model suits tech-savvy homeowners with higher hot water needs and robust electrical systems.”
14kW Tankless Electric Water Heater 240V for Sink & Shower, Gray
This 14kW model offers reliable on-demand hot water for one or two fixtures, making it ideal for smaller setups. Compared to the Westinghouse 14kW, it provides similar flow but lacks smart WiFi features, which might be a downside for tech enthusiasts. Its compact size and straightforward installation appeal to DIYers, yet it requires a dedicated 60-amp circuit, possibly demanding electrical upgrades. While energy-efficient at 99.8%, its flow rate limits its use to low-demand households. It’s a solid choice for those who prioritize simplicity and affordability over multi-point capacity.
Pros:- Energy-efficient with minimal standby power loss
- Compact and easy to install in tight spaces
- High thermal efficiency for quick hot water
- Simple digital temperature control
Cons:- Requires electrical upgrade to a 60A breaker, possibly complex
- Limited to 1-2 usage points, not suitable for bigger households
- Potential installation challenges for non-experts
Best for: Singles or couples with minimal hot water points needing an efficient, space-saving solution
Not ideal for: Larger households or homes with multiple bathrooms due to limited flow capacity
- Power:14kW
- Voltage:240V
- Dimensions:15.87″ x 11.14″ x 2.87″
- Water Connection:1/2″ NPT
- Temperature Range:86°F to 131°F
- Efficiency:99.8%
Our verdict“Best suited for small households seeking a reliable and energy-efficient hot water solution at a budget-friendly price.”
Westinghouse 14kW Tankless Electric Water Heater, 240V, WiFi, Gray
The Westinghouse 14kW unit provides instant hot water within 3 seconds, thanks to its advanced heating technology. Its smart WiFi controls, compatible with Alexa and Google Home, distinguish it from simpler models like the Rheem 11kW, offering remote operation and voice commands. Its compact, space-saving design makes it suitable for small homes with limited space. However, it demands a dedicated 60A double-pole breaker, which could require electrical upgrades, and its flow rate of 3.4 GPM limits use to households with fewer fixtures. This unit excels for tech-inclined users wanting seamless smart home compatibility.
Pros:- Provides hot water in just 3 seconds
- Smart WiFi with voice control compatibility
- Space-efficient wall-mount design
- Durable with anti-corrosion and scale reduction features
Cons:- Requires dedicated 60A double-pole breaker and professional wiring
- Limited flow rate of 3.4 GPM, restricting simultaneous use
- Potential installation complexity
Best for: Homeowners wanting smart control and quick hot water for small households or apartments
Not ideal for: Larger families or homes needing high flow rates for multiple simultaneous fixtures
- Power Source:Hard Wiring
- Wattage:14 KW
- Voltage:240V
- Flow Rate:3.4 GPM
- Maximum Temperature:140°F
- Item Dimensions:9.56″W x 12.59″H
- Color:Gray
Our verdict“Ideal for smart home enthusiasts who need quick hot water in small residences with limited fixture demands.”
Rheem 11kW Multi Fixture Tankless Electric Water Heater – 240V
The Rheem 11kW model offers reliable hot water for up to 2 fixtures, making it a practical choice for small households. Its digital temperature controls allow precise adjustments, and its no-venting design simplifies installation compared to larger units like Rheem RTEX-24. While its 2.68 GPM flow rate limits its use for larger households or simultaneous multiple fixtures, it provides consistent performance for basic needs. The smaller size and straightforward setup make it accessible for DIY installation, but electrical requirements such as a 240V supply and professional wiring remain essential.
Pros:- Compact and space-saving design
- Digital temperature controls for accuracy
- No venting required simplifies installation
- Affordable price point
Cons:- Limited flow rate restricts use to 1-2 fixtures
- Requires professional electrical installation
- Not suitable for larger households with higher demand
Best for: Small households or couples with limited hot water points seeking a reliable, budget-friendly option
Not ideal for: Homes with multiple bathrooms or high simultaneous hot water demand
- Power:11kW
- Voltage:240V
- Flow Rate:2.68 GPM
- Temperature Range:80°F – 140°F
- Warranty:5-Year Leak, 1-Year Parts
Our verdict“This unit works well for small households with minimal hot water needs and a tight budget.”
18kW Electric Tankless Water Heater 240V WiFi Certified
The 18kW model offers a flow rate of 4.3 GPM, making it suitable for small homes with moderate hot water demand. Its WiFi control, energy-saving self-modulating technology, and safety features make it a versatile choice. Compared with the 27kW unit, it sacrifices some capacity but reduces electrical complexity and cost, appealing to those with space limitations. Its maximum pressure of 130 psi and ease of installation are additional advantages. However, its flow rate may fall short for larger households or simultaneous use of multiple fixtures, and professional electrical setup is necessary.
Pros:- Provides continuous hot water without delays
- WiFi remote control for convenience
- Space-efficient wall-mounted design
- Energy savings up to 99%
Cons:- Requires specific electrical setup with dual 40A breakers
- Limited maximum flow rate of 4.3 GPM
- Installation may need professional help
Best for: Small households with moderate hot water needs and limited space, seeking smart control
Not ideal for: Homes with higher demand or multiple bathrooms requiring greater flow capacity
- Power:18,000 watts
- Voltage:240 volts
- Flow Rate:4.3 gpm
- Maximum Temperature:140 °F
- Item Dimensions:11.1″ W x 19.2″ H
- Item Weight:12 pounds
Our verdict“Suitable for small homes with moderate hot water needs and a preference for smart control features.”
ThermoMate 18kW Electric Tankless Water Heater, On Demand Instant Hot Water, 240V
This model stands out for its high power output of 18kW, making it capable of providing instant hot water for most small households. Compared to the Rheem 18kW (B01MR7Z39V), it offers a similar flow rate but features a more compact design that saves wall space. Its self-modulating technology ensures energy is used efficiently, but the high power requirement means you’ll need a dedicated two 40-amp circuit, which could complicate installation. The digital temperature display allows precise control, essential for households wanting customizable hot water at multiple points, yet the installation complexity may deter DIYers. This heater is ideal for small families or couples seeking reliable, whole-house hot water without multiple units. However, it may lead to higher energy costs if used continuously at full capacity.
Pros:- Provides instant, unlimited hot water for multiple points
- Energy-efficient with self-modulating technology
- Compact wall-mounted design saves space
Cons:- Requires two 40-amp double-pole breakers for installation
- Installation can be complex for DIY users
- High power consumption may increase energy bills
Best for: Small households needing reliable, whole-house hot water with energy efficiency.
Not ideal for: Homeowners without sufficient electrical capacity or those seeking a simple plug-and-play solution.
- Power:18kW
- Voltage:240V
- Flow Rate:Up to 4.4 GPM
- Dimensions:17.12″ x 13.12″ x 3.12″
- Water Connection:3/4″ NPT
- Certifications:ETL
Our verdict“This heater suits small households that want reliable, whole-house hot water with efficient energy use, provided they can handle the electrical needs.”
14kW Tankless Electric Water Heater ORBEK On Demand 240V 3.38 GPM
The ORBEK 14kW heater provides up to 3.38 GPM, making it an excellent choice for small households or point-of-use applications. Compared to the Rheem RTEX-24 (B01MS9DVEE), it offers a lower flow rate but at a more accessible price point. Its high efficiency can deliver up to 60% energy savings, ideal for those prioritizing cost savings. The compact dimensions make it easy to install in tight spaces, but the 150-amp circuit requirement might be a hurdle for some homeowners, especially in older homes with limited electrical capacity. Its limited flow rate means it’s better suited for one or two outlets simultaneously, unlike larger units that can handle multiple fixtures. This makes it suitable for small families or single-point applications but not for larger households needing simultaneous hot water at multiple fixtures.
Pros:- Provides instant hot water for 1-2 points of use
- High efficiency with significant energy savings
- Compact and space-saving design
Cons:- Requires a 150 amp circuit breaker and proper wiring
- Installation may be challenging for some users
- Limited flow rate may not serve larger households
Best for: Small households or single-point applications where budget and space are limited.
Not ideal for: Larger families or homes requiring multiple fixtures at once, due to its limited flow rate.
- Power:14kW
- Voltage:240V
- Flow Rate:3.38 GPM
- Temperature Range:86°F to 140°F
- Dimensions:14.2″H x 9.5″L x 3.1″W
Our verdict“This heater is best for small households or single-point use where budget and space are considerations, accepting limited simultaneous hot water flow.”
18kW Tankless Electric Water Heater 240V for Whole House, Gray
The 18kW model offers a reliable solution for small homes needing hot water at multiple points. Compared with the Rheem 18kW (B01MR7Z39V), it emphasizes smart temperature control with LED indicators and safety features that are appealing for households seeking ease of use. Its high thermal efficiency ensures instant hot water, but like most high-power units, it requires two 40-amp circuit breakers, which might increase installation costs. While it can serve 3-4 fixtures simultaneously, this capacity may fall short in larger households or during peak demand. The sleek design and energy efficiency make it a strong candidate for those prioritizing reliability, though electrical setup complexity is a consistent concern.
Pros:- Energy-efficient with up to 50% cost savings
- Instant hot water with high thermal efficiency
- Smart LED temperature control and safety features
Cons:- Requires two 40-amp circuit breakers
- Limited to 3-4 simultaneous fixtures
- Installation may need professional electrical work
Best for: Small homes needing reliable, multi-point hot water with straightforward controls.
Not ideal for: Homes with limited electrical capacity or those seeking a simple plug-in solution.
- Power:18kW
- Voltage:240V
- Dimensions:15.87″ x 11.14″ x 2.87″
- Water Connection:3/4″ NPT
- Temperature Range:86°F to 131°F
Our verdict“A solid choice for small homes where reliable, multi-point hot water is needed, provided electrical requirements are met.”
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater
The Rheem RTEX-24 stands out for its 5.9 GPM flow rate, making it suitable for larger small households or those with multiple fixtures. Compared to the 18kW options, it provides a higher hot water output but requires a more robust electrical connection, similar to the Rheem 18kW (B01MR7Z39V). Its compact design makes it easy to fit into tighter spaces, and digital temperature controls ensure precise adjustment. However, its higher power draw means more substantial electrical upgrades are necessary, potentially increasing installation costs. It’s an attractive option for those who need more hot water capacity without sacrificing space, but it’s less suitable if electrical capacity is limited.
Pros:- Space-saving compact design
- High flow rate for multiple fixtures
- Digital thermostatic temperature controls
Cons:- Requires specific electrical wiring and breaker setup
- Higher power consumption increases energy costs
- Limited for very large households or high-demand scenarios
Best for: Small households or apartments requiring higher flow rates with limited installation space.
Not ideal for: Homes with restricted electrical service or those seeking a simple, low-power unit.
- Power:24kW
- Voltage:240V
- Flow Rate:Up to 5.9 GPM
- Temperature Range:80°F – 140°F
- Warranty:5-Year Leak, 1-Year Parts
Our verdict“Ideal for small households needing higher hot water flow in a compact form, assuming electrical capacity is sufficient.”
Rheem 18kW 240V Tankless Electric Water Heater, Gray
This 18kW Rheem model offers dependable performance with a flow rate of 4.4 GPM, making it suitable for small households with moderate hot water needs. Its self-modulating feature adjusts power based on demand, helping to manage energy costs, similar to the ThermoMate 18kW but with a more traditional design. The digital LED thermostat provides precise temperature control, and its copper immersion heating elements enhance durability. However, the electrical setup requires professional installation, and the flow rate might be limiting in households with multiple simultaneous fixtures. Compared to higher wattage units, it strikes a balance between capacity and installation complexity, making it well-suited for users with moderate needs and existing electrical capacity.
Pros:- Self-modulation for energy efficiency
- Durable copper heating elements
- Digital LED temperature control
Cons:- Requires professional electrical installation
- Flow rate may be insufficient for multiple fixtures
- Limited capacity for high-demand scenarios
Best for: Small households seeking a durable, self-modulating heater with reliable performance.
Not ideal for: Larger households or those expecting high simultaneous hot water demand.
- Power:18kW
- Voltage:240V
- Flow Rate:Up to 4.4 GPM
- Water Connection:3/4″ NPT
- Color:Gray
Our verdict“Best for small households wanting a durable, self-adjusting heater that balances capacity and installation needs.”
How We Picked
I evaluated these electric tankless water heaters based on performance, ease of installation, build quality, energy efficiency, and overall value. Capacity was matched to typical small house needs, ensuring enough hot water without overspending. I prioritized models with positive safety certifications and user-friendly features such as WiFi control. The ranking reflects a balance between power, usability, and cost, aiming to help small house owners find a reliable, efficient solution that fits their budget and space constraints.Factors to Consider When Choosing Electric Tankless Water Heater For Small House
Choosing an electric tankless water heater for a small house requires understanding several key factors beyond basic features. Proper sizing, safety certifications, and installation requirements can make or break your experience. Being aware of common pitfalls—such as overestimating your household’s hot water demand or ignoring electrical capacity—helps you make a smarter purchase. This guide covers the main considerations to ensure your new heater offers reliable service and good value.Capacity and Flow Rate
Matching the heater’s capacity to your household’s hot water needs is essential. Small houses often use lower flow rates, but if multiple fixtures are used simultaneously, a higher wattage unit is necessary. Overestimating capacity can lead to unnecessary costs, while underestimating results in cold surprises. Consider your peak usage to select a model that provides enough hot water without wasting energy.
Electrical Requirements and Wiring
Most small house units demand a dedicated 240V circuit with sufficient amperage. Upgrading your electrical system might be necessary, especially for higher wattage models. Failing to meet electrical requirements can lead to safety hazards or unit malfunction. Always check your home’s electrical capacity and consult a professional if unsure about wiring or circuit breaker needs.
Size and Installation Space
Compact design is a typical advantage for small houses, but some models are bulkier than others. Consider available space near your water outlets and whether installation will be wall-mounted or free-standing. Easy installation reduces overall costs and disruption, so prioritize units that fit your space and are straightforward to set up, especially if you plan DIY installation.
Energy Efficiency and Operating Cost
Electric tankless heaters are generally energy-efficient, but some models include features like WiFi control or anti-scale systems that can further reduce operating costs. Be wary of units with high standby power consumption or those that require frequent maintenance. Investing in a slightly more efficient model can save money over time, especially if you plan to use hot water frequently.
Certifications and Safety Features
Look for safety certifications such as ETL or UL to ensure the unit meets safety standards. Features like automatic shutoff, temperature controls, and leak detection add peace of mind. These elements are especially important in small houses where space is limited, and safety is paramount. Skipping certification verification can lead to safety hazards or voided warranties.
Frequently Asked Questions
Can I install an electric tankless water heater myself in a small house?
While some small models are designed for DIY installation, most require electrical wiring adjustments and proper safety measures. If you’re comfortable with electrical work and follow the manufacturer’s instructions carefully, self-installation might be feasible. However, for safety and compliance reasons, hiring a licensed electrician is generally recommended, especially for units with higher power requirements.
Will a small house need a high-wattage heater for multiple fixtures?
Yes, if you plan to run multiple hot water outlets simultaneously, a higher wattage unit provides better flow and temperature stability. Lower wattage models may suffice for single fixtures, like a bathroom sink, but can struggle with multiple simultaneous usages. Always estimate your peak demand to avoid cold water surprises during busy times.
Are WiFi-enabled water heaters worth the extra cost for a small house?
WiFi features offer convenience, such as remote temperature control and maintenance alerts, which can be helpful for tech-savvy users. In a small house, these features are not essential but add value if you want to monitor or adjust settings remotely. Consider whether the added cost aligns with your budget and whether you prioritize smart home integration.
How do I know if my electrical system can support a high-wattage heater?
Check your existing circuit breaker and wiring capacity—most small house units require dedicated 240V circuits with sufficient amperage, often 30-50 amps. If your current system is insufficient, an upgrade may be necessary, which can add to installation costs. Consulting a licensed electrician before purchasing helps prevent overloads and safety issues.
What maintenance is needed for electric tankless water heaters in a small house?
Maintenance typically involves flushing the unit periodically to prevent mineral buildup and checking for leaks or corrosion. Many models include self-diagnostic features or alerts for maintenance needs. Regular upkeep ensures efficient operation and prolongs the lifespan, especially in areas with hard water where scale can be a concern. Following manufacturer guidelines simplifies ongoing maintenance.
Conclusion
For small house owners seeking the best overall performance, the 27kW Tankless Water Heater Electric 240V WiFi offers a reliable mix of power and convenience. Budget-conscious buyers will find the 14kW Tankless Electric Water Heater 240V for Sink & Shower provides solid value without sacrificing essential features. Those needing a premium option with advanced controls should consider the Rheem RTEX-24 24kW for its durability and high capacity. Beginners or those with limited electrical capacity are better served by models with lower wattage and simpler installation. Tailor your choice to your household size, electrical setup, and budget for the best results.
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