The 8 Best Tankless Water Heaters of 2024

Choosing the best tankless water heater involves considering several key factors, from energy efficiency to size requirements for your home. Tankless models, known for providing hot water on demand without the need for a storage tank, have gained popularity for their energy savings and space-saving design.

Brands like Rinnai and Rheem lead the market, offering high-performance models that cater to both propane and gas needs.

Reviews highlight the advantages of tankless systems over traditional tank models, including lower operating costs and a continuous supply of hot water.

Ideal for large homes, the best tankless water heaters ensure you never run out of hot water while also contributing to reduced energy bills.

With a variety of brands and models to choose from, it’s essential to compare features and consumer reports to find the unit that best fits your home’s needs and preferences.

Best Choice: Stiebel Eltron Tempra 36 Plus Tankless Water Heater

Tankless Water Heater Benefits

Opting for a tankless water heater brings a plethora of advantages to homeowners seeking both efficiency and convenience. Unlike traditional water heaters, tankless versions heat water directly without the need for a storage tank, leading to a continuous flow of hot water.

This means no more cold showers and waiting for the water to heat up again. Energy savings are another significant benefit, as these heaters only operate on demand, reducing energy consumption by up to 50% compared to their tank-based counterparts.

The compact design of tankless water heaters also frees up valuable space in homes, making them ideal for smaller residences or for those looking to declutter.

1. Stiebel Eltron Tempra 24 Plus Tankless Water Heater

The Stiebel Eltron Tempra 24 Plus Tankless Water Heater is a revolutionary solution for your hot water needs, offering an innovative and eco-friendly way to ensure a continuous flow of hot water.

This German-engineered heater features Advanced Flow Control technology to maintain consistent water temperatures, even when demand exceeds capacity, meaning your hot showers will never be interrupted.

Its sleek, compact white design not only saves space but also energy, with auto-modulation and the ability to electronically control water flow, making it an eco-friendly unit that significantly reduces energy costs.

• Special Feature: LED Display
• Capacity: Continuous Flow
• Material: Copper
• Dimensions: 16.63″W x 14.5″H
• Weight: 20 Pounds

Stiebel Eltron Tankless Water Heater

Key Features/Why Best

• Advanced Flow Control for consistent temperatures
• Space and energy-efficient design
• Easy operation with noise-free functionality
• Eco-friendly with significant energy savings
• Comprehensive warranties included

Compatible For

• Whole house use
• Eco-conscious households
• Space-limited installations

2. Rinnai V75IN Tankless Hot Water Heater

The Rinnai V75IN Tankless Hot Water Heater brings efficiency and convenience to a new level with its compact, high-performance design. Designed for indoor installation and powered by natural gas, this heater provides an endless hot water supply with an energy factor of .82 for both gas types.

Its leak detection system minimizes property damage by shutting off water to the unit if a leak is detected. The temperature range can be controlled with precision, ensuring that your water is always at the perfect temperature for your needs.

It’s an ideal choice for homes of all sizes, offering up to 7.5 GPM for a powerful, constant stream that can serve multiple appliances simultaneously.

• Special Feature: Energy Factor of .82, Leak Detection
• Capacity: 7.5 Gallons Per Minute
• Material: Durable Construction
• Dimensions: 30″W x 13″H
• Weight: 45.6 Pounds

Rinnai V75IN Tankless Hot Water Heater

Key Features/Why Best

• Unlimited hot water flow
• Energy and space efficient
• High-performance 7.5 GPM flow rate
• Advanced safety with leak detection
• Durable with extensive warranties

Compatible For

• Medium to large homes
• Multiple simultaneous appliance use
• Energy-conscious homeowners

3. EcoSmart ECO 18 Electric Tankless Water Heater

The EcoSmart ECO 18 Electric Tankless Water Heater stands out for its patented Self Modulating Technology, ensuring efficient water heating for homes. Manufactured with durability in mind, this compact and user-friendly device provides a consistent supply of hot water on demand.

It’s designed to adjust its energy consumption based on how much hot water is needed, which can lead to savings of up to 60% on water heating costs.

The sleek design, combined with a digital temperature control allowing adjustments in 1-degree increments, offers complete control over your hot water supply, fitting perfectly in any modern home.

Its compact size saves valuable storage space, making it an ideal solution for those looking to enhance their home’s energy efficiency without sacrificing comfort.

• Special Feature: LED Display
• Capacity: 5 Gallons
• Material: Plastic
• Dimensions: 14″W x 17″H
• Weight: 14 Pounds

EcoSmart ECO 18 Electric Tankless Water Heater

Key Features/Why Best

• Saves up to 60% on heating costs
• Digital temperature control
• Compact, space-saving design
• Durable and easy to use
• Lifetime warranty for residential use

Compatible For

• Small to medium-sized homes
• Climates with incoming water temperature above 62°F
• Modern energy-efficient homes

4. Rinnai RL75IN Tankless Hot Water Heater

Rinnai’s RL75IN Tankless Hot Water Heater, designed for natural gas and indoor installation, delivers up to 7.5 gallons per minute, ensuring that you never run out of hot water even when multiple fixtures are in use.

This high-efficiency model is renowned for its original design featuring Circ-Logic technology, which allows for customizable recirculation patterns to match your household habits. Its compact size, similar to a small suitcase, does not compromise its capacity to provide endless hot water, making it a perfect addition to medium and large homes.

The Rinnai RL75IN is not only a smart investment for your home but also a durable one, with warranties that guarantee its long-term performance. It represents a blend of innovation and convenience, offering a seamless solution to your hot water needs.

• Special Feature: Energy Factor of .82 for both gas types
• Capacity: 7.5 Gallons
• Material: Metal
• Dimensions: 17.5″W x 31″H
• Weight: 54 Pounds

Rinnai RL75IN Tankless Hot Water Heater

Key Features/Why Best

• High GPM rate for multiple fixtures
• Compact and saves floor space
• Durable with extensive warranties
• Smart design with Circ-Logic technology
• Energy Star certified for efficiency

Compatible For

• Medium to large-sized homes
• Indoor installation areas
• Households with high hot water demand
• Energy-conscious homeowners seeking efficiency
• Homes requiring a compact water heating solution

5. EcoSmart ECO 27 Electric Tankless Water Heater

The EcoSmart ECO 27 Electric Tankless Water Heater revolutionizes hot water systems with its advanced technology and efficiency. This model stands out for its ability to provide endless on-demand hot water with precise temperature control within 1 degree of the selected temperature, ensuring consistent performance and comfort.

Its compact design, at 90% smaller than traditional tank heaters, allows for versatile installation options, including wall mounting or at the point of use, making it a perfect fit for any home.

The ECO 27 is not only space-saving but also energy-efficient, capable of saving up to 50% in water heating costs by heating water only when needed, thanks to its 99% thermal energy efficiency.

This model is ideal for whole-home applications, providing between 2.7 and 6.5 gallons per minute depending on the inlet water temperature, making it a reliable solution for varying demands.

• Special Feature: LED Display
• Capacity: 3 Gallons
• Material: Plastic
• Dimensions: 17″W x 17″H x 3.5″D
• Weight: 11 pounds

EcoSmart ECO 27 Electric Tankless Water Heater

Key Features/Why Best

• Endless on-demand hot water
• Space and energy-efficient design
• Digital temperature control
• 99% thermal energy efficiency
• Significant savings on water heating costs

Compatible For

• Whole home applications
• Cold climates or high flow rates
• Energy-conscious homeowners

6. Rinnai V53DeN Outdoor Tankless Water Heater

The Rinnai V53DeN Outdoor Tankless Water Heater is a powerhouse of efficiency and reliability, designed to meet the needs of energy-conscious homeowners. This model provides endless hot water for your entire home with a compact and durable design that fits seamlessly into any outdoor space.

The V53DeN is remarkably energy and space-efficient, heating water only when necessary and featuring enhanced scale detection to minimize the risk of long-term damage.

It delivers a high-performance hot water flow rate of up to 5.3 gallons per minute, capable of serving up to 4 appliances simultaneously. This tankless gas water heater is backed by Rinnai’s solid warranties, ensuring peace of mind and reliable performance for years to come.

The unit’s smart design and high efficiency make it an ideal choice for those looking to save energy and enjoy a constant supply of hot water.

• Special Feature: Euro White color
• Capacity: 5.3 Gallons
• Material: Metal
• Dimensions: 18″W x 31.2″H
• Weight: 33 pounds

Rinnai V53DeN Outdoor Tankless Water Heater

Key Features/Why Best

• Unlimited hot water supply
• Compact, outdoor-friendly design
• High GPM for multiple applications
• Energy-efficient operation
• Long-term reliability with solid warranties

Compatible For

• Outdoor installations
• Medium to large-sized homes
• Energy-efficient households
• Multiple simultaneous hot water uses

7. Stiebel Eltron Tempra 36 Plus Tankless Water Heater

The Stiebel Eltron Tempra 36 Plus Tankless Water Heater stands out for its innovative design and efficient performance, providing an endless supply of hot water on demand. With its sleek white appearance, this electric water heater saves significant space and does not require venting, making it a versatile addition to any home.

The advanced technology includes an LED display for easy temperature control, ensuring comfort and convenience. The German-engineered copper heating elements offer durability and efficiency, while the exclusive Advanced Flow Control technology automatically adjusts the water flow, guaranteeing a constant water temperature and uninterrupted hot water supply. This model is particularly energy-efficient, using 15-20% less energy than conventional tank water heaters, potentially offering even greater savings depending on usage habits.

• Special Feature: LED Display
• Capacity: 0.39 Gallons
• Material: Copper
• Dimensions: 16.63″W x 14.5″H
• Weight: 19 Pounds

Stiebel Eltron Tempra 36 Plus Tankless Water Heater

Key Features/Why Best

• Continuous, unlimited hot water
• Space-saving design
• Silent operation
• Advanced Flow Control technology
• Energy-efficient

Compatible For

• Single and multi-bathroom homes
• Eco-conscious households
• Areas with space constraints
• High demand hot water applications

8. Rheem 18kW 240V Tankless Electric Water Heater

The Rheem 18kW Tankless Electric Water Heater combines functionality and efficiency, ideal for mid-range whole-home applications. It features an external digital thermostatic control with an LED display for precise temperature management. The unit’s self-modulating technology adjusts power to meet hot water demand, ensuring energy savings and a continuous supply of hot water.

Designed for easy installation with bottom 3/4 inch NPT water connections, this heater’s compact size allows it to be placed almost anywhere. The durable copper immersion heating elements are field-serviceable, highlighting the unit’s convenience and reliability. With up to 4.4 GPM flow rate, it meets the hot water needs of most homes efficiently.

• Special Feature: LED Display
• Capacity: 18 Gallons
• Material: Stainless Steel
• Dimensions: 14.5″W x 18.25″H
• Weight: 14.78 Pounds

Rheem 18kW 240V Tankless Electric Water Heater

Key Features/Why Best

• Precise temperature control
• Self-modulating energy savings
• Easy installation
• Continuous hot water supply
• Compact and durable design

Compatible For

• Mid-sized homes
• Single shower applications
• Multiple point-of-use installations
• Energy-efficient households

Efficiency and Cost-Effectiveness

Analyzing the efficiency and cost-effectiveness of tankless water heaters reveals their potential for significant savings over time. These units are known for their high Energy Factor (EF) ratings, indicating superior energy efficiency.

By heating water on demand, they eliminate the standby energy losses associated with storage water heaters. Initial installation costs may be higher, but the reduction in monthly energy bills can compensate for this over the heater’s lifespan.

Furthermore, many utility companies offer rebates for the installation of energy-efficient appliances, including tankless water heaters, further enhancing their cost-effectiveness.

It’s essential to consider both the upfront costs and long-term savings to fully understand the economic benefits of going tankless.

Buying Guide: How We Selected the Best Tankless Water Heater

Identifying the top tankless water heaters available requires a meticulous approach to ensure that consumers can make informed decisions. Our selection process is rooted in a blend of market research, customer review analysis, and hands-on testing, ensuring that we recommend products that not only meet but exceed expectations.

Market Research

Our journey began with extensive market research to identify the most promising tankless water heaters based on their popularity, technology, and innovation. We focused on models that offered a blend of energy efficiency, reliability, and advanced features like digital displays and self-modulating technology. This initial sift helped narrow down the vast options to a curated list of potential top performers.

Customer Review Analysis

Understanding real-world experiences is crucial. We dove into customer reviews across multiple platforms to gauge satisfaction levels, durability concerns, and the effectiveness of each unit in a variety of climates and households.

This feedback provided invaluable insights into the operational strengths and weaknesses of each model, highlighting user-reported issues and appreciated benefits.

Hands-on Testing

To further refine our selections, we conducted rigorous hands-on testing of the finalists. This included evaluating the ease of installation, the speed of heating, energy consumption rates, and overall performance under different water usage scenarios. Models that demonstrated a consistent supply of hot water without significant loss of pressure or temperature fluctuations were favored.

Energy Efficiency and Cost Analysis

Energy efficiency and long-term cost savings play a significant role in our selection process. We compared the energy consumption rates against the potential savings on utility bills, considering both the upfront cost and the operational expenses over time. Models that balanced high efficiency with reasonable purchase and installation costs were prioritized.

This comprehensive approach ensures that our recommendations for the best tankless water heaters stand up to scrutiny, offering exceptional performance, reliability, and value for our readers.

Read More: Best Electric Baseboard Heaters

Selecting for Large Homes

Capacity and Flow Rate: For large homes, selecting a tankless water heater with adequate capacity is crucial. Look for models that offer a high gallons-per-minute (GPM) flow rate to accommodate simultaneous demands from multiple bathrooms and appliances.

Energy Source: Decide between electric and gas models based on availability and utility costs in your area. Gas-powered units typically provide higher flow rates, making them suited for larger households.

Efficiency Ratings: Higher efficiency ratings mean lower operating costs. Look for ENERGY STAR® certified models for maximum energy savings.

Brand Reliability and Warranty: Choose reputable brands known for durability and reliability. A strong warranty offers peace of mind and protection for your investment.

Brand and Model Comparisons

Comparing tankless water heater brands and models is essential to finding the best fit for your needs. Brands like Rheem, Stiebel Eltron, and Rinnai offer a range of models with varying capacities, energy efficiencies, and features.

For instance, Rheem excels in electric tankless models known for easy installation and robust performance. Stiebel Eltron’s models stand out for their advanced flow control technology, ensuring consistent water temperatures.

Meanwhile, Rinnai is renowned for its gas-powered units, offering high flow rates and efficiency. Evaluating these aspects alongside user reviews and professional ratings can guide consumers to make an informed decision.

Installation Insights

1. Choose the Right Location: Identify an appropriate place for installation that minimizes the distance to hot water uses, reducing lag time and heat loss.

2. Ensure Proper Venting (for gas models): Follow manufacturer guidelines for venting gas models to ensure safety and optimal performance.

3. Electrical and Plumbing Requirements: Verify that your home meets the electrical and plumbing requirements for the chosen model, including amperage, voltage, and pipe size.

Maintenance Tips

Regular maintenance is vital to extend the lifespan and efficiency of tankless water heaters. Flushing the system annually removes mineral build-up, preventing efficiency loss and damage.

It’s also important to check the air and water filters periodically, cleaning or replacing them as needed to ensure proper airflow and water quality.

Keeping an eye on system error codes and consulting the user manual or a professional for troubleshooting can prevent minor issues from becoming major problems.

User Experiences: Pros and Cons

Pros

• Unlimited hot water supply
• Reduced energy bills
• Space-saving design
• Longevity

Cons

• Higher initial cost
• Possible need for system upgrades
• Limited flow rate under extreme demand

Common Questions on Tankless Water Heaters

Is a Tankless Water Heater Right for Every Home?

Not all homes will benefit equally from a tankless water heater. Homes with high hot water demand, those located in regions with colder incoming water temperatures, and households looking to improve energy efficiency could see the most benefits. It’s essential to evaluate your household’s specific needs and consult with a professional to determine if a tankless system is suitable for your situation.

Can Tankless Water Heaters Work with Hard Water?

Tankless water heaters can work with hard water, but the mineral buildup may reduce efficiency over time. It’s advisable to install a water softener if you have hard water to extend the lifespan of the unit and maintain its efficiency. Regular maintenance, such as descaling, is also more critical in areas with hard water.

What Is the Expected Lifespan of a Tankless Water Heater?

Tankless water heaters typically have a longer lifespan than traditional tank models, often lasting up to 20 years or more with proper maintenance. This compares favorably to the 10-15-year lifespan of many tank heaters, making tankless models a more durable long-term investment.

Do Tankless Water Heaters Provide Instant Hot Water?

While tankless water heaters provide a continuous supply of hot water, there may still be a brief wait for hot water to reach the tap, especially if the heater is located far from the point of use. Recirculation systems or point-of-use tankless water heaters can help mitigate this delay.

Are Tankless Water Heaters More Expensive Than Traditional Models?

Initially, tankless water heaters tend to be more expensive in terms of both the unit cost and installation. However, the increased energy efficiency and longer lifespan can lead to lower operational costs over time, potentially offsetting the higher upfront investment.

Concluding Recommendation

Considering the detailed discussion and analysis above, it’s clear that tankless water heaters offer numerous benefits, including energy efficiency, space savings, and a continuous supply of hot water. For those looking to make an upgrade, the Stiebel Eltron Tempra 36 Plus Tankless Water Heater is a top recommendation. This model combines high performance, energy savings, and advanced features like precise temperature control and a sleek, compact design, making it an excellent investment for modern homes. Its proven reliability and customer satisfaction scores make it a standout choice for anyone considering the switch to a tankless water heating system.