When it comes to tankless gas water heaters, the right model can provide you with endless hot water, higher energy efficiency, and lower utility bills compared to traditional tank heaters. Whether you’re looking for a model to handle high water demand or a compact option for smaller homes, tankless gas units are powerful, fast, and space-saving. Based on my experience installing and maintaining these systems, here are the best gas-powered tankless water heaters available in 2024:
1. Rinnai RUR199iN – Best Overall for Large Homes
The Rinnai RUR199iN is a top-tier model perfect for large households with multiple bathrooms. This natural gas tankless water heater has an impressive 11 GPM (gallons per minute) flow rate, which means it can handle multiple fixtures running simultaneously without dropping temperature. What sets this model apart is its Circ-Logic recirculation technology, which delivers hot water faster by recirculating water through the pipes, minimizing wait time.
Key Features:
- Flow Rate: 11 GPM
- Best For: Large homes with high hot water demands
- Fuel Type: Natural gas
- Efficiency: 0.95 Uniform Energy Factor (UEF)
- Recirculation Pump: Built-in recirculation system for instant hot water
- Wi-Fi Capable: Compatible with Wi-Fi monitoring for remote control
- Temperature Range: 98°F to 140°F
Pros:
- Excellent flow rate for large households
- Recirculation technology saves water and reduces wait times
- Wi-Fi compatibility for monitoring and control
- Highly efficient with low NOx emissions
- Long-lasting with a robust warranty
Cons:
- Higher upfront cost
- Requires professional installation due to venting and recirculation system
2. Rheem RTGH-95DVLN – Best Value for Money
The Rheem RTGH-95DVLN strikes an excellent balance between cost, efficiency, and performance, making it a great value for most families. It’s designed for indoor use and provides a flow rate of up to 9.5 GPM, which is suitable for homes with 2-3 bathrooms. Rheem’s tankless models are known for being energy-efficient and easy to install, and this model is no different.
Key Features:
- Flow Rate: 9.5 GPM
- Best For: Mid-to-large-sized homes
- Fuel Type: Natural gas
- Efficiency: 0.93 UEF
- Condensing Technology: Increases efficiency and reduces heat loss
- EcoNet Wi-Fi Capable: Monitor and control water heater via app
- Built-in Hot Start Programming: Prevents cold water sandwiches
Pros:
- Affordable compared to similar high-end models
- Great efficiency with condensing technology
- Wi-Fi compatibility for remote monitoring
- High flow rate supports multiple fixtures
- Easy to install and maintain
Cons:
- Slightly lower GPM compared to the Rinnai for very large homes
- Venting installation can be tricky for DIYers
3. Noritz NRC66DVNG – Best for Small to Medium Homes
The Noritz NRC66DVNG is a compact but powerful tankless gas water heater, perfect for small to medium-sized homes. I’ve installed this unit in homes with 1-2 bathrooms, and it delivers consistent hot water without issue. The 6.6 GPM flow rate may seem lower compared to other models, but it’s more than sufficient for homes that don’t need to run multiple fixtures at once. Its condensing technology also makes it energy-efficient.
Key Features:
- Flow Rate: 6.6 GPM
- Best For: Small to medium homes
- Fuel Type: Natural gas
- Efficiency: 0.91 UEF
- Low NOx Emissions: Eco-friendly design
- Compact Size: Fits into tight spaces, making it great for smaller homes
- Temperature Range: 100°F to 140°F
Pros:
- Affordable and compact for smaller spaces
- Ideal for single-family homes with moderate water needs
- Energy-efficient condensing technology
- Easy to install and maintain
- Durable with a long lifespan
Cons:
- Lower flow rate not suitable for large households
- No Wi-Fi connectivity
4. Takagi T-H3-DV-N – Best for High Demand & Commercial Use
The Takagi T-H3-DV-N is a high-powered commercial-grade tankless water heater that performs exceptionally well in large homes or light commercial settings (like restaurants or offices). It can deliver up to 10 GPM and has an outstanding 0.95 UEF efficiency rating, thanks to its condensing technology. It’s built for heavy use and can handle multiple simultaneous hot water demands.
Key Features:
- Flow Rate: 10 GPM
- Best For: Large homes or commercial use
- Fuel Type: Natural gas
- Efficiency: 0.95 UEF
- Commercial-grade heat exchanger for durability
- Dual Heat Exchanger system improves energy efficiency
Pros:
- Excellent flow rate for large households or businesses
- Designed to handle heavy usage and multiple fixtures
- Highly energy-efficient with condensing technology
- Durable commercial-grade components
- Long warranty, especially for residential use
Cons:
- More expensive due to its commercial-grade design
- Requires professional installation and venting
5. Bosch Greentherm 9000 Series – Best for Energy Efficiency
The Bosch Greentherm 9000 Series (Model 9000i SE or 9900 SE depending on availability) is known for its superior energy efficiency and sleek design. With up to 0.96 UEF, this unit is one of the most energy-efficient gas tankless water heaters available. It’s perfect for eco-conscious homeowners looking to reduce energy consumption while still having access to endless hot water.
Key Features:
- Flow Rate: 9 GPM
- Best For: Eco-friendly homeowners, mid-to-large homes
- Fuel Type: Natural gas
- Efficiency: 0.96 UEF
- Wi-Fi Enabled: Can be controlled via app
- Easy Venting Options: Flexible venting solutions make installation easier
- Modulating Burners: Helps maintain consistent temperatures with less energy waste
Pros:
- Extremely high energy efficiency
- Wi-Fi connectivity for smart home integration
- Compact and sleek design
- Easy to install with flexible venting options
- Quiet operation
Cons:
- Slightly higher price point due to high efficiency
- Lower flow rate compared to other large home models
Comparison of the Best Tankless Gas Water Heaters
| Model | Best For | Flow Rate (GPM) | Efficiency (UEF) | Key Features | Price Range |
|---|---|---|---|---|---|
| Rinnai RUR199iN | Large homes, high demand | 11 GPM | 0.95 | Built-in recirculation, Wi-Fi compatible, instant hot water | $$$$ |
| Rheem RTGH-95DVLN | Mid-to-large homes, value buyers | 9.5 GPM | 0.93 | Condensing tech, EcoNet Wi-Fi, Hot Start Programming | $$$ |
| Noritz NRC66DVNG | Small to medium homes | 6.6 GPM | 0.91 | Compact design, low NOx emissions | $$ |
| Takagi T-H3-DV-N | High-demand homes, commercial use | 10 GPM | 0.95 | Commercial-grade, dual heat exchangers, energy efficient | $$$$ |
| Bosch Greentherm 9000 | Energy-efficient, eco-friendly | 9 GPM | 0.96 | Modulating burners, Wi-Fi enabled, flexible venting | $$$$ |
What to Consider When Choosing a Tankless Gas Water Heater
- Flow Rate (GPM):
- The flow rate determines how much hot water the unit can provide at once. Larger homes or homes with multiple simultaneous users should opt for a model with at least 9 GPM or more.
- Efficiency (UEF):
- A higher Uniform Energy Factor (UEF) means the unit is more efficient. Condensing units, like the Rinnai RUR199iN or Bosch Greentherm, tend to be more efficient because they reuse heat from exhaust gases.
- Venting Requirements:
- Gas tankless units require proper venting, either direct or power venting. Make sure you account for venting needs in your installation costs, as professional installation is often required.
- Recirculation Feature:
- Recirculation technology, like in the Rinnai RUR199iN, ensures faster hot water delivery and reduces water waste, making it a great option for homes with long water pipes.
- Installation Costs:
- While gas tankless water heaters are more energy-efficient in the long run, they tend to be pricier to install than electric units due to venting and gas line requirements.
Final Recommendation
- For large homes or heavy hot water use, the Rinnai RUR199iN is hands-down the best choice due to its high flow rate, recirculation pump, and overall reliability.
- For mid-sized homes looking for good value, the Rheem RTGH-95DVLN offers great performance at a lower cost while still providing a solid GPM and efficiency.
- For smaller homes or apartments, the Noritz NRC66DVNG provides a compact, energy-efficient solution with reliable performance at a budget-friendly price.
Tankless gas water heaters are an investment, but with the right choice, you’ll enjoy endless hot water, lower energy bills, and a long-lasting system.