7 Best Tankless Water Heater (Reviews)
Tankless water heaters have revolutionized the way we access hot water at home, offering energy savings, endless hot water, and space-saving designs. Unlike traditional tank heaters that store and constantly reheat water, tankless models heat water on demand, reducing energy consumption and utility bills. With modern advancements, today’s best tankless water heaters deliver consistent performance for everything from small apartments to large family homes.
Choosing the right tankless water heater can seem daunting, given the array of options-gas vs. electric, indoor vs. outdoor, and various flow rates. The right unit will depend on your household’s hot water needs, fuel availability, and installation constraints. In this guide, I’ll leverage my experience and thorough research to present the 7 best tankless water heaters available on Amazon and beyond, each excelling in efficiency, reliability, and user satisfaction. Whether you’re upgrading for energy savings or building a new home, these models stand out for their innovative features and proven performance.
Let’s break down how to select the perfect tankless water heater before diving into the top picks for 2025.
How to Choose the Best Tankless Water Heater
As someone who’s reviewed plumbing solutions for years, I know that picking the right tankless water heater boils down to a few critical factors:
- Fuel Type: Decide between electric, natural gas, or propane. Gas models generally deliver higher flow rates, ideal for large households, while electric units are easier to install and maintain.
- Flow Rate (GPM): Measured in gallons per minute, this determines how many fixtures can run simultaneously. Calculate your peak hot water demand-showers, sinks, appliances-to find a suitable GPM.
- Energy Efficiency: Look for ENERGY STAR® certification and features like self-modulation or condensing technology for maximum savings.
- Installation Location: Some units are designed for indoor use, others for outdoor. Consider venting requirements, climate, and available space.
- Durability and Warranty: A solid warranty and robust construction ensure years of reliable service.
- Smart Features: Wi-Fi connectivity, digital displays, and remote monitoring add convenience and control.
Now, let’s explore the 7 best tankless water heaters that consistently earn high marks for performance and value.
7 Best Tankless Water Heaters
01. Rinnai RU199iN Tankless Water Heater
The Rinnai RU199iN is a powerhouse for larger homes with high hot water demand. This natural gas unit boasts a flow rate of up to 11 GPM, easily supporting multiple showers and appliances running at once. Its ThermaCirc360™ technology ensures faster hot water delivery, while ENERGY STAR® certification guarantees top-tier efficiency. Built-in Wi-Fi capability allows remote monitoring and control, and the robust heat exchangers are designed for long-term durability. If you want consistent, whole-house hot water without sacrificing efficiency, the RU199iN is a standout choice for 2025.
02. EcoSmart ECO 27 Electric Tankless Water Heater
Perfect for smaller homes or point-of-use applications, the EcoSmart ECO 27 is a compact, highly efficient electric model. It delivers up to 6.6 GPM, making it suitable for moderate water demand. Its self-modulating technology adjusts energy usage based on hot water needs, ensuring 99% thermal efficiency. The sleek, wall-mounted design saves space, and precise temperature controls provide consistent hot water, even in colder climates. It’s easy to install and maintain, making it a favorite for budget-conscious homeowners seeking reliable performance.
03. Takagi T-H3-DV-N Tankless Water Heater
The Takagi T-H3-DV-N is a top pick for high-demand households needing robust performance. This natural gas, condensing unit delivers up to 10 GPM and features advanced condensing technology for improved energy efficiency. With ENERGY STAR® certification and a 0.95 Uniform Energy Factor (UEF), it’s both powerful and eco-friendly. Safety features like freeze protection and troubleshooting diagnostics add peace of mind. Its compact size and ability to link with additional units make it versatile for growing families or multi-bathroom homes.
04. Rheem Performance Tankless Electric Water Heater
Rheem’s Performance Tankless Electric Water Heater is a versatile, whole-house solution that can support up to five showers at once. Its self-modulating technology automatically adjusts energy consumption to match your household’s hot water needs, maximizing efficiency. The digital display and easy-to-use controls allow precise temperature adjustments. With a reliable brand reputation and straightforward installation, this model is ideal for midsize to large homes seeking continuous hot water and significant energy savings.
05. Stiebel Eltron Tempra 24 Plus Electric Tankless Water Heater
The Stiebel Eltron Tempra 24 Plus is renowned for its German engineering, reliability, and ultra-quiet operation. It features advanced flow control technology, ensuring a steady temperature even when multiple fixtures are in use. The digital display and sleek design make it user-friendly, while the self-modulation feature optimizes energy usage. This electric model is perfect for homes that prioritize both performance and silent operation, and it consistently earns high marks for durability and efficiency.
06. Rinnai V53DeP Tankless Hot Water Heater
For those seeking an outdoor solution, the Rinnai V53DeP is a reliable propane-powered unit designed for easy installation and high performance. It’s compact, weather-resistant, and delivers quick, consistent hot water. This model is ideal for homes where indoor installation is impractical or for vacation properties and cabins. Its straightforward controls and robust build ensure years of trouble-free service, making it a top choice for outdoor tankless water heating.
07. Bosch Tronic 3000 ES4 Mini-Tank Water Heater
While technically a mini-tank, the Bosch Tronic 3000 ES4 is a versatile, point-of-use solution that acts like a tankless heater for quick hot water at sinks, bathrooms, or utility rooms. It’s compact enough to fit under a sink and provides instant hot water with minimal wait. This electric unit is ideal for supplementing your main water heater or addressing hot water delays in distant fixtures. Its easy installation and reliable performance make it a favorite for small spaces and secondary applications.
Final Thoughts
The best tankless water heater for your home depends on your unique needs, from whole-house capacity to point-of-use convenience. The models above represent the leading choices for 2025, each excelling in efficiency, reliability, and user satisfaction. When selecting your unit, consider your household’s hot water demand, fuel availability, and installation requirements to ensure years of comfortable, energy-efficient hot water. With these top picks, you can say goodbye to cold showers and hello to endless, on-demand hot water.
