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10 Best Booster For Water Heaters 2025 in the United States
#1
Winner
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
The Stiebel Eltron Tempra 24 Plus is a tankless water heater that caters to users seeking a continuous hot water supply without the interruption of traditional heaters. Its advanced flow control technology ensures a consistent temperature, making it suitable for households needing reliable hot showers. The compact design is a space saver and eco-friendly, as it includes auto-modulation to manage energy usage efficiently.
Rating
9.7
Chosen by1,485
Flow Rate
Temperature Rise
Compatibility
Most important from
2080 reviews
#2
Ecosmart ECO 24 24 KW at 240-Volt Electric Tankless Water Heater with Patented Self Modulating Technology, 17 x 17 x 3.5
The EcoSmart ECO 24 is a powerful and efficient electric tankless water heater designed to boost water heating systems. With a power rating of 24,000 watts and a maximum flow rate of 5.8 gallons per minute, it is capable of providing substantial hot water for residential use. One of its standout features is the patented self-modulating technology, which adjusts energy usage based on the water flow, enhancing efficiency and saving on energy costs.
Rating
9.4
Flow Rate
Temperature Rise
Installation Requirements
Most important from
325 reviews
#3
EcoSmart ECOS 27 Tankless Electric Water Heater, 27 kW at 240 Volts, 112.5 Amps with Self Modulating Technology
The EcoSmart ECOS 27 is a tankless electric water heater with a substantial power rating of 27 kW at 240 volts, which means it can handle multiple low-flow applications simultaneously, such as a bathroom and a small kitchen sink. Its self-modulating technology is a notable strength, as it adjusts energy use based on hot water demand, making it highly energy efficient—claimed to be up to 96% thermal energy efficient. This feature can significantly save on energy costs compared to traditional tank heaters that continuously maintain water temperature.
Rating
9.2
Installation Requirements
Most important from
3 reviews
Top 10 Best Booster For Water Heaters 2025 in the United States
#1
Winner
9.7 score
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
Power Rating: 24kW
Temperature Rise: 68°F to 140°F
Installation Requirements: 150 A electric service, professional help
Safety Features: Limit max water temperature, prevent scalding
Chosen by 1485 this week
Ecosmart ECO 24 24 KW at 240-Volt Electric Tankless Water Heater with Patented Self Modulating Technology, 17 x 17 x 3.5
Ecosmart ECO 24 24 KW at 240-Volt Electric Tankless Water Heater with Patented Self Modulating Technology, 17 x 17 x 3.5
Power Rating: 24000 watts
Flow Rate: 5.8 Gallons Per Minute
Compatibility: 240-volt, 100 A circuit breaker
Installation Requirements: Wall mounting, rough plumbing
EcoSmart ECOS 27 Tankless Electric Water Heater, 27 kW at 240 Volts, 112.5 Amps with Self Modulating Technology
EcoSmart ECOS 27 Tankless Electric Water Heater, 27 kW at 240 Volts, 112.5 Amps with Self Modulating Technology
Power Rating: 27 KW
Flow Rate: 6.6 Gallons Per Minute
Installation Requirements: 240-volt, 112.5 amps
Safety Features: Monitors water temperature
Rheem RTEX-36 36kW Electric Tankless Water Heater 240V Ext Adj Temp Ctrl Bot 3/4 in. Npt Con
Rheem RTEX-36 36kW Electric Tankless Water Heater 240V Ext Adj Temp Ctrl Bot 3/4 in. Npt Con
Power Rating: 36 kW
Flow Rate: 6 Gallons Per Minute
Compatibility: 240 Volts
Installation Requirements: 240V electrical connection
Eemax HATB007240 Tank Water Heater Booster 7.2 kW 240V
Eemax HATB007240 Tank Water Heater Booster 7.2 kW 240V
Power Rating: 7.2 kW
Flow Rate: 5 GPM
Temperature Rise: up to 45%
Compatibility: new and existing heaters
Installation Requirements: compact design, zero clearance
Safety Features: ETL certified
Related Products
Hatco C-12 Compact Electric Booster Water Heater 12 KW
Hatco C-12 Compact Electric Booster Water Heater 12 KW
Power Rating: 12 KW
Compatibility: various systems
Installation Requirements: 240V-3PH setup
Eemax EEM24018 Electric Tankless Water Heater, Blue
Eemax EEM24018 Electric Tankless Water Heater, Blue
Power Rating: 18 KW
Flow Rate: 3.5 GPM
Temperature Rise: 80°F to 140°F
Compatibility: Up to 3.5 GPM
Installation Requirements: 25-150 psi
Safety Features: Digital temp control
6 Gal Compact Booster Water Heater - Hatco C-7
6 Gal Compact Booster Water Heater - Hatco C-7
Power Rating: 240 Volts
Compatibility: align with plumbing and heater systems
Installation Requirements: indoor, 118 pounds
Cash Acme 3/4 Inch Tank Booster Water Heater with Thermostatic Mixing Valve, Temperature Gauge, Braided Hose, Domestic and Commercial Application, PEX Pipe, PE-RT, CPVC, Copper, 24644
Cash Acme 3/4 Inch Tank Booster Water Heater with Thermostatic Mixing Valve, Temperature Gauge, Braided Hose, Domestic and Commercial Application, PEX Pipe, PE-RT, CPVC, Copper, 24644
Power Rating: Corded Electric
Temperature Rise: 120°F to 140°F
Compatibility: Gas, electric, tankless water heaters
Installation Requirements: Push-to-connect, no soldering needed
Safety Features: Maintains safe temperature, lead-free brass
#10
7.2 score
Bosch Thermotechnology Tronic 6100 Electric Tankless Water Heater, 18 kW, White
Bosch Thermotechnology Tronic 6100 Electric Tankless Water Heater, 18 kW, White
Power Rating: 18 kW
Flow Rate: 0.55 GPM
Compatibility: 230 volts
Installation Requirements: No venting required
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Buying Guide for the Best Booster For Water Heaters
Choosing the right booster for your water heater can significantly improve the efficiency and performance of your water heating system. A booster helps to increase the temperature of the water, ensuring you have a consistent supply of hot water, especially during peak usage times. To make an informed decision, you need to consider several key specifications that will determine the suitability and effectiveness of the booster for your specific needs.Power RatingThe power rating of a booster is measured in kilowatts (kW) and indicates how much energy the booster uses to heat the water. This spec is important because it affects how quickly the booster can heat the water and how much energy it consumes. Boosters typically range from 1.5 kW to 12 kW. Lower power ratings (1.5-3 kW) are suitable for small households with minimal hot water needs, while higher power ratings (6-12 kW) are better for larger households or commercial use where there is a high demand for hot water. Choose a power rating that matches your household size and hot water usage patterns.
Flow RateThe flow rate, measured in liters per minute (L/min), indicates how much hot water the booster can supply at a given time. This is crucial for ensuring that you have enough hot water for all your needs, especially during peak times. Flow rates can vary from 5 L/min to 20 L/min. Lower flow rates (5-10 L/min) are adequate for small households or single-point applications like a single shower or faucet. Higher flow rates (15-20 L/min) are necessary for larger households or multiple simultaneous uses. Assess your household's hot water usage to determine the appropriate flow rate.
Temperature RiseTemperature rise refers to the increase in water temperature that the booster can achieve, typically measured in degrees Celsius (°C). This spec is important because it determines how much hotter the water will be after passing through the booster. Temperature rise can range from 20°C to 60°C. A lower temperature rise (20-30°C) is suitable for areas with relatively warm incoming water, while a higher temperature rise (40-60°C) is necessary for colder climates or when a significant increase in water temperature is required. Consider the incoming water temperature and your desired hot water temperature to choose the right temperature rise.
CompatibilityCompatibility refers to how well the booster integrates with your existing water heater system. This is important to ensure that the booster works efficiently and safely with your current setup. Some boosters are designed to work with specific types of water heaters, such as tankless or storage water heaters. Check the manufacturer's specifications to ensure that the booster is compatible with your water heater type. If you are unsure, consult with a professional to determine the best match for your system.
Installation RequirementsInstallation requirements include the space, electrical, and plumbing needs for setting up the booster. This spec is important because it affects the ease and cost of installation. Some boosters require professional installation due to complex electrical or plumbing connections, while others can be installed by a knowledgeable DIYer. Consider the available space near your water heater, the electrical capacity of your home, and your comfort level with installation tasks. Choose a booster that fits your installation capabilities and constraints.
Safety FeaturesSafety features are built-in mechanisms that protect the booster and your home from potential hazards. This is crucial for ensuring safe operation and preventing accidents. Common safety features include thermal cut-off, pressure relief valves, and overheat protection. These features help to prevent overheating, pressure build-up, and electrical faults. Look for boosters with comprehensive safety features to ensure reliable and safe operation. Prioritize safety features that address the specific risks associated with your water heating system.