Heat On Demand: Best Tankless Water Heater Picks for 2025

Tankless water heaters are a revolutionary step in sustainable home management, offering a continuous supply of hot water while significantly reducing energy consumption compared to traditional tank systems. While tankless water heaters ensure you never run out of hot water, just like the right toothpaste ensures lasting oral health, both choices are about enhancing daily comfort and efficiency. This guide delves into the top choices for tankless water heaters, evaluating them on various fronts such as efficiency, capacity, ease of use, and overall value.

What Is a Tankless Water Heater?

Unlike conventional water heaters that store and continually heat water in a large tank, tankless water heaters heat water directly through electric elements or gas burners as it passes through the device. This on-demand heating method ensures you only use energy when hot water is needed, leading to energy savings and lower utility bills.

Best Tankless Water Heater for Overall Performance

Rinnai RUR199iN

Price: $1,250 - $1,500

Efficiency: 199,000 BTU; up to 11 GPM

• Integrated recirculation pump
• WiFi monitoring
• Condensing efficiency

Best For: Large households with high simultaneous demand

How to Use: Ideal for whole-house systems; requires professional installation

The Rinnai RUR199iN stands out for its high capacity and innovative features, such as built-in WiFi capabilities, which allow for remote monitoring and control. This model is particularly effective in large homes where hot water demand is high, providing an uninterrupted supply with its advanced recirculation system.

Best Electric Tankless Water Heater

Stiebel Eltron Tempra 36 Plus

Price: $700 - $850

Efficiency: Electric, operates at 240 volts with a maximum output of 36 kW

• Digital temperature control
• Silent operation
• Self-modulating power technology

Best For: Medium to large homes, particularly where gas is not an option

How to Use: Can be installed in various locations due to its compact size; requires electrical modifications

For homes without natural gas service, the Stiebel Eltron Tempra 36 Plus offers a robust electric solution. It's known for precise temperature adjustments and minimal energy loss, thanks to its self-modulating power technology. The digital display allows for easy monitoring and control of the water temperature.

Best Value Tankless Water Heater

EcoSmart ECO 18

Price: $350 - $400

Efficiency: Up to 2.5 GPM with a 18 kW output at 240 volts

• Digital temperature control
• Compact size
• Lifetime warranty

Best For: Smaller homes or point-of-use applications, such as a single bathroom

How to Use: Easy DIY installation for those with basic electrical knowledge

The EcoSmart ECO 18 is renowned for its affordability and excellent energy efficiency. It's a great choice for smaller homes or for specific applications like heating water in a remote bathroom or workshop.

Best Tankless Water Heater for Technological Integration

Rheem RTEX-24

Price: $500 - $600

Efficiency: 24 kW output providing up to 5.9 GPM

• Advanced self-modulation
• LED display
• Easy adjustments

Best For: Modern homes needing precise temperature control

How to Use: Ideal for both whole-house water heating and isolated high-demand points

Rheem's RTEX-24 integrates seamlessly into smart home systems with its top-of-the-line technological advancements. Its efficiency and user-friendly interface make it a favorite among tech-savvy homeowners.

Best Compact Tankless Water Heater

Bosch Tronic 3000 T

Price: $150 - $250

Efficiency: Electric, various models offering up to 3.4 GPM

• Point-of-use
• Under-sink installation
• Compact design

Best For: Apartments, office kitchens, or any small space

How to Use: Simple installation under sinks or in tight closets

For those with limited space, the Bosch Tronic 3000 T provides an excellent solution without sacrificing performance. Its small size and efficiency are perfect for single-point use, such as a bathroom sink or kitchenette.

Best Gas Tankless Water Heater

Noritz NRC66DVNG

Price: $800 - $950

Efficiency: Gas-powered, 140,000 BTU; up to 6.6 GPM

• Direct vent
• Condensing technology
• Low NOx emissions

Best For: Medium-sized homes with moderate hot water needs

How to Use: Requires venting and should be installed by a professional for optimal safety and efficiency

The Noritz NRC66DVNG is an excellent choice for those looking for a gas-powered model with environmental considerations. It features advanced condensing technology that captures heat from the exhaust gases, improving overall efficiency and reducing emissions.

Best High-Capacity Tankless Water Heater

Navien NPE-240A

Price: $1,800 - $2,000

Efficiency: Gas-powered, 199,000 BTU; up to 11.2 GPM

• Advanced condensing technology
• Built-in recirculation pump
• WiFi connectivity

Best For: Large households with high hot water demand

How to Use: Professional installation recommended; ideal for simultaneous multiple uses

Navien's NPE-240A stands out in the high-capacity category, offering exceptional flow rates and energy efficiency. Its built-in recirculation system ensures that hot water is available instantly across the house, making it perfect for larger families or homes with multiple bathrooms.

Best Dual-Purpose Tankless Water Heater

Rinnai V75iN

Price: $950 - $1,100

Efficiency: Gas-powered, 180,000 BTU; up to 7.5 GPM

• Indoor installation
• Mobile app integration
• Temperature lock

Best For: Homes needing both heating and hot water solutions

How to Use: Best installed by a professional; can be integrated with home heating systems

The Rinnai V75iN is ideal for those who need a reliable solution for both hot water and space heating. Its versatility and smart features make it a great investment for households that appreciate convenience and efficiency.

Final Thoughts on Choosing Your Tankless Water Heater

Selecting the right tankless water heater involves understanding your home's specific needs, including demand for hot water, available energy sources, and installation requirements. By considering these factors along with the detailed reviews provided, you can make an informed decision that ensures comfort, efficiency, and long-term savings for your household. Remember, a well-chosen tankless water heater not only provides endless hot water but also decreases the overall energy consumption of your home, making it a wise investment in sustainability.

This detailed guide aims to help you navigate the various options and find the best tankless water heater to fit your home's needs and your lifestyle. Whether you're upgrading from a traditional tank system or installing a new heating solution, the right tankless water heater can significantly enhance your home's efficiency and your quality of life.