In today’s world, efficiency and convenience are paramount when it comes to home appliances, especially water heaters. Tankless gas water heaters have surged in popularity because they provide endless hot water on demand, save space, and reduce energy consumption compared to traditional tank heaters.
If you’re tired of running out of hot water mid-shower or want to cut down on your utility bills, switching to a tankless model is a smart investment. These units heat water only when needed, eliminating standby energy loss and offering a more eco-friendly solution for your household. Whether you have a large family or a smaller home, there’s a tankless gas water heater that fits your needs and budget.
Shopping for the best tankless gas water heater on Amazon can be overwhelming given the variety of models, brands, and features available. To help you make an informed choice, I’ve researched and tested the top-rated tankless gas water heaters available on Amazon in 2025. This guide will walk you through the best options, highlighting their key features, energy efficiency, flow rates, and smart technology integrations. By the end, you’ll be equipped with expert insights to select the perfect unit for your home, ensuring reliable hot water supply and long-term savings.
How to Choose the Best Tankless Gas Water Heater
Choosing a tankless gas water heater isn’t just about picking the most popular model. From my experience as a home appliance reviewer and after consulting industry experts, here are the critical factors you should consider:
- Flow Rate (GPM): This measures how many gallons per minute the heater can supply. Larger households or homes with multiple bathrooms require higher GPM to ensure simultaneous hot water use without drops in temperature.
- Energy Efficiency: Look for units with high Energy Star ratings and Uniform Energy Factor (UEF) scores. Condensing models tend to be more efficient as they recycle exhaust heat.
- Fuel Type Compatibility: Most tankless heaters run on natural gas or propane. Make sure the model you choose matches your home’s gas supply.
- Smart Features: Some models offer Wi-Fi connectivity and smartphone apps for remote monitoring and temperature control, enhancing convenience and energy savings.
- Installation Requirements: Gas tankless heaters often require professional installation, including venting and gas line adjustments. Check the installation complexity and costs.
- Warranty and Support: A longer warranty period and responsive customer service are signs of a reliable brand.
By focusing on these factors, you can find a tankless gas water heater that fits your household’s hot water demands, budget, and lifestyle.
Top 10 Tankless Gas Water Heaters Available on Amazon in 2025
01. Noritz EZ Series Pro Condensing Tankless Water Heater

The Noritz EZ Series Pro is a top-tier tankless gas water heater known for its exceptional energy efficiency and powerful heating capacity. Certified by Energy Star with a UEF of 0.98, it leads the market in reducing energy waste. This condensing model uses a secondary heat exchanger to capture more heat from exhaust gases, allowing it to operate efficiently while using simpler PVC venting. It delivers a robust flow rate suitable for medium to large households, heating water up to 199,900 BTU. The unit supports Bluetooth and Wi-Fi connectivity, enabling remote control and monitoring via a smartphone app. Although it comes with a higher upfront cost, Noritz backs it with a 25-year warranty, reflecting confidence in its durability and performance. This model is ideal for homeowners seeking a blend of cutting-edge efficiency and smart home integration.
02. Rinnai RU199iN Tankless Water Heater

The Rinnai RU199iN is a premium natural gas tankless water heater favored for its reliability and high flow rate of up to 11 GPM, making it perfect for larger homes with multiple simultaneous water demands. It features advanced temperature controls and recirculation technology to minimize wait times for hot water, conserving water and energy. Rinnai’s reputation for durability and excellent customer support adds to the appeal. While installation requires professional expertise, the unit’s long-term energy savings and consistent performance justify the investment. Its compact design also helps save space in utility areas.
03. Rheem Prestige Tankless Water Heater

Rheem’s Prestige Tankless Water Heater offers a balance of performance and affordability. It provides a flow rate suitable for average-sized households and features a self-diagnostic system that simplifies maintenance. The Prestige model boasts a high energy efficiency rating and supports remote monitoring through an optional Wi-Fi module. Its compact size and straightforward installation make it a popular choice for homeowners upgrading from traditional tank heaters. Rheem’s strong warranty and brand reliability further enhance its value proposition.
04. EcoSmart ECO 24 Tankless Water Heater

The EcoSmart ECO 24 is a popular choice for those seeking an energy-efficient, compact unit that fits smaller homes or apartments. While primarily electric, it is often paired with gas models for hybrid setups. It provides precise temperature control and boasts a good flow rate for its size. Its digital self-modulating technology adjusts energy use based on demand, optimizing efficiency. The ECO 24’s easy installation and maintenance make it a favorite for DIY enthusiasts, though gas models are generally preferred for higher flow needs.
05. Stiebel Eltron Tankless Water Heater

Known for German engineering, the Stiebel Eltron tankless water heater combines sleek design with reliable performance. It offers consistent water temperature and energy savings through advanced heat exchanger technology. While more common in electric versions, the gas models provide robust heating suitable for moderate household use. Its quiet operation and compact footprint are additional benefits. Stiebel Eltron units are backed by solid warranties and responsive customer service.
06. Rinnai V53DeP Tankless Water Heater

The Rinnai V53DeP is a smaller, more budget-friendly gas tankless water heater designed for point-of-use applications or smaller households. It delivers reliable hot water with a decent flow rate and includes user-friendly digital controls. Its compact size allows installation in tight spaces, and it supports propane or natural gas. This model is ideal for those seeking an economical solution without sacrificing qualit.
07. Rheem RTGH-95DVLN Prestige Series

This Rheem model is designed for larger homes with high hot water demand. It features a high flow rate, advanced recirculation technology, and excellent energy efficiency. The RTGH-95DVLN also supports Wi-Fi connectivity for remote management. Its durable construction and comprehensive warranty make it a trustworthy choice for families needing consistent hot water supply.
08. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater

The Takagi T-KJr2-IN-NG is a compact, affordable gas tankless water heater suitable for small to medium homes. It offers reliable performance with a flow rate that supports multiple fixtures and includes safety features like freeze protection. Its straightforward installation and maintenance requirements appeal to homeowners seeking a hassle-free upgrade.
09. Bosch Therm 940 ES NG Tankless Water Heater

Bosch’s Therm 940 ES NG is a high-efficiency condensing gas tankless water heater with a strong flow rate and Energy Star certification. It features advanced electronic controls and a compact design that fits easily in tight spaces. Bosch’s reputation for quality and innovation makes this a solid choice for energy-conscious consumers.
10. Rinnai Sensei RXP Models

The Rinnai Sensei RXP series represents the pinnacle of tankless water heater technology with ultra-high flow rates, top-tier energy efficiency, and smart home integration. These models include Wi-Fi connectivity, advanced diagnostics, and recirculation pumps to reduce water waste. They are ideal for large homes or light commercial use, offering long-term savings and exceptional performance.
Final Thoughts
Choosing the right tankless gas water heater means balancing your household’s hot water needs with energy efficiency and budget. The models listed above are all available on Amazon, offering a range of features and price points to suit different homes. Investing in a quality tankless water heater not only enhances comfort but also contributes to lower energy bills and a smaller environmental footprint. With proper installation and maintenance, these units can provide reliable hot water for years to come.