When searching for the best tankless gas water heater condensing, the focus is on high efficiency, reliable performance, and suitability for your home’s hot water needs. The Rinnai V53DeN stands out as the overall top pick thanks to its proven durability and excellent flow rate, making it ideal for most households. The Rheem RTGH Series offers exceptional efficiency and ultra-low NOx emissions, perfect for eco-conscious buyers. Meanwhile, models like the Noritz GQ-C3261WX-FF provide advanced features like Bluetooth control, appealing to tech-savvy homeowners. Still, choosing the right unit involves balancing upfront costs, capacity, and installation requirements. Continue reading for a detailed breakdown of these options and what makes each one unique.
Complete the kit
Key Takeaways
- The top-rated models combine high flow rates with energy-efficient condensing technology to maximize savings.
- Features like Bluetooth control and safety systems distinguish premium options from basic units.
- Capacity varies significantly; selecting a model with the right GPM is crucial for household size and usage patterns.
- Installation complexity and venting requirements are key considerations that impact total project costs.
- Quality and durability are consistent across brands like Rinnai, Rheem, and Noritz, but tradeoffs exist in price and features.
| tankless gas water heater condensing | Flow Rate | Warranty | BTU |
|---|---|---|---|
| Rinnai V53DeN Natural Gas Tank | 5.3 GPM | 10-year on heat exchanger, 5-year on parts and labor | — |
| Rheem RTGH Series 9.0 GPM Natu | 9.0 GPM | 15-year heat exchanger | — |
| Noritz GQ-C3261WX-FF US EZ Ser | 11.1 GPM | 5 years parts, 1 year labor | 199,900 |
| Vancepic Condensing Natural Ga | 5.1 GPM | 2 years | 120,000 |
| Noritz NR98-DVC NG Concentric | 7.5 GPM | — | 199,000 |
| Rheem RTG Series 7.0 GPM Liqui | 7.0 GPM | 15-year heat exchanger, 5-year parts | 160,000 BTUs |
| Rinnai CU160iN Commercial Natu | 9 GPM | 8-year heat exchanger, 5-year parts, 1-year labor | — |
| Noritz NR98SVNG 7.5 GPM Indoor | 9.8 GPM | — | — |
| Rinnai RSC160iN Smart-Circ Con | Up to 9 GPM | — | 160,000 BTU |
| Rinnai RX130iN Condensing Smar | 7.1 GPM | 15-year heat exchanger, 5-year parts/labor | — |
| ThermoMate Condensing Tankless | 5.28 GPM | — | 114,000 BTU |
More Details on Our Top Picks
Rinnai V53DeN Natural Gas Tankless Water Heater
The Rinnai V53DeN excels as a reliable outdoor tankless heater, offering a balanced mix of compact size and consistent performance. Its 5.3 GPM flow rate suits small to medium households needing hot water for up to four fixtures, making it more versatile than the smaller Vancepic model, which is limited to fewer outlets. While its energy efficiency is notable, the requirement for professional installation and the need for warranty registration can be hurdles for some DIY-focused buyers. Its outdoor design is a clear advantage over indoor-only units like the Rheem RTGH Series, but performance may fluctuate in colder climates or with inconsistent gas supply. This model is perfect for homeowners wanting dependable outdoor heat without sacrificing space, but those seeking higher flow rates or indoor installation may prefer other options.
Pros:- Compact outdoor design saves indoor space
- Reliable 5.3 GPM flow rate for multiple fixtures
- Long-lasting 10-year warranty on heat exchanger
Cons:- Requires professional installation, adding cost and complexity
- Flow rate may be insufficient for larger households or high-demand situations
Best for: Homeowners seeking a space-saving outdoor heater with reliable performance for small to medium homes
Not ideal for: Large households needing over 5 GPM or indoor installation without outdoor access, due to limited flow rate and outdoor-only design
- Flow Rate:5.3 GPM
- Warranty:10-year on heat exchanger, 5-year on parts and labor
- Installation:Outdoor, space-saving design
- Fuel Type:Natural Gas
Our verdict“This outdoor model suits small to medium households prioritizing space-saving and outdoor installation, but not those with high hot water demands.”
Rheem RTGH Series 9.0 GPM Natural Gas Tankless Water Heater Indoor, 180,000 BTUs, High Efficiency, Condensing, Ultra-Low NOx
The Rheem RTGH Series offers a substantial 9.0 GPM flow rate, making it ideal for large families or households with multiple bathrooms. Compared with the Noritz GQ-C3261WX-FF, which provides a slightly higher flow of 11.1 GPM but at a higher price and complexity, Rheem strikes a balance of efficiency and capacity. Its high efficiency (0.93 UEF) translates to lower energy bills over time, and the ultra-low NOx emissions meet strict environmental standards. However, it demands indoor installation with venting and professional setup, which could be a barrier for DIY owners. The 15-year heat exchanger warranty offers peace of mind, but the need for adequate indoor space makes it less suitable for small or outdoor setups. This heater is a solid choice for large households prioritizing efficiency and environmental compliance over installation simplicity.
Pros:- Large 9.0 GPM flow rate supports multiple simultaneous outlets
- High efficiency reduces energy costs over time
- Ultra-low NOx emissions for environmental compliance
- Digital temperature control with high precision
Cons:- Requires indoor venting and professional installation
- Indoor space needed limits placement options
Best for: Families with high hot water needs, indoor space, and a desire for long-term efficiency
Not ideal for: Small households or renters seeking portable or outdoor units, due to installation requirements
- Flow Rate:9.0 GPM
- BTUs:180,000
- Efficiency:0.93 UEF
- Warranty:15-year heat exchanger
Our verdict“Ideal for large, environmentally conscious households willing to handle indoor installation and venting requirements.”
Noritz GQ-C3261WX-FF US EZ Series Pro 11.1 GPM 199,900 BTU Natural Gas Tankless Water Heater with Bluetooth
The Noritz EZ Series Pro stands out for its impressive 11.1 GPM flow rate and Bluetooth connectivity, offering advanced control and diagnostics for tech-savvy homeowners. Its energy efficiency (0.98 UEF) is a standout, especially compared to less efficient models like the Noritz NR98-DVC, which has a lower efficiency rating. The Bluetooth feature enables remote management, making maintenance and troubleshooting more convenient. However, it requires a 120V power connection and may not be suitable for locations without easy electrical access. Its high capacity makes it perfect for larger households, but the limited one-year labor warranty and the need for proper venting could be drawbacks for some buyers. This model fits well for those seeking high performance and smart features, with a willingness to handle installation complexities.
Pros:- High 11.1 GPM flow rate supports multiple outlets simultaneously
- Bluetooth connectivity for remote control and diagnostics
- High energy efficiency with 0.98 UEF
- Durable stainless steel heat exchangers
Cons:- Requires 120V electrical connection, limiting placement options
- Limited labor warranty of 1 year
Best for: Large households or those seeking remote control and diagnostics via Bluetooth
Not ideal for: Small homes or renters without electrical access, due to power requirements
- Flow Rate:11.1 GPM
- BTU:199,900
- Energy Star Certified:Yes
- Warranty:5 years parts, 1 year labor
Our verdict“This high-capacity, smart-enabled heater is best for tech-savvy large households willing to handle installation and electrical needs.”
Vancepic Condensing Natural Gas Tankless Water Heater Indoor, 120,000 BTU, 5.1 GPM, On Demand Instant Hot Water Heater with Digital Control and Safety Features
The Vancepic Condensing heater offers a practical solution for small households or apartments, with a 5.1 GPM flow rate and 120,000 BTU output. Its condensing technology ensures good energy efficiency, and the digital control panel simplifies temperature management. Compared to larger units like the Rheem RTGH Series, it is more suitable for lower demand scenarios, but its flow rate limits its utility in bigger households. Installation might require professional setup, especially for venting and condensate drainage, which could be a hurdle for DIY buyers. The safety features, including anti-freeze protection, make it a reliable choice for indoor use. However, its limited flow capacity means it’s best for smaller families or secondary applications rather than high-demand environments.
Pros:- Compact size ideal for small spaces
- Efficient condensing technology reduces energy costs
- Digital control panel for precise temperature adjustments
- Safety features including anti-freeze protection
Cons:- Flow rate of only 5.1 GPM limits capacity for high demand
- Installation complexity due to venting and condensate drainage
Best for: Small households or apartments seeking space-efficient, reliable hot water
Not ideal for: Large families or homes with multiple bathrooms that demand higher flow rates
- BTU:120,000
- Flow Rate:5.1 GPM
- Temperature Range:95°F – 149°F
- Warranty:2 years
Our verdict“This model is well-suited for small homes or apartments prioritizing space, efficiency, and safety, but not for larger households with greater hot water needs.”
Noritz NR98-DVC NG Concentric Direct Vent Tankless Water Heater
The Noritz NR98-DVC offers a reliable 7.5 GPM flow rate with a 199,000 BTU output, making it suitable for medium to large households. Its 84% efficiency is respectable, though slightly below high-end models like the Rheem RTGH Series. The self-diagnostic system simplifies maintenance, and the concentric venting allows for straightforward installation, especially where space is limited. Compared to the Noritz GQ-C3261WX-FF, which provides higher flow, the NR98-DVC balances capacity with easier venting options. Its higher upfront cost and specific venting requirements might deter budget-conscious buyers. This unit fits well for those seeking a dependable, moderately high-capacity heater with simplified installation, especially with existing concentric venting systems.
Pros:- Reliable 7.5 GPM flow supports multiple outlets
- Simple concentric venting for easier installation
- Self-diagnostic system for easier maintenance
- Good thermal efficiency at 84%
Cons:- Requires specific venting setup, which can be complex
- Limited to natural gas supply, no propane option
- Potentially higher initial cost compared to simpler models
Best for: Homes requiring a reliable, moderate flow heater with straightforward venting options
Not ideal for: High-demand households needing over 8 GPM or those without suitable venting space, due to venting complexity
- Flow Rate:7.5 GPM
- BTU:199,000
- Efficiency:84%
- Venting:3-inch by 5-inch concentric
Our verdict“A solid choice for households needing dependable capacity with simplified venting, but not suited for very high demand or venting challenges.”
Rheem RTG Series 7.0 GPM Liquid Propane Tankless Water Heater Indoor
The Rheem RTG Series 7.0 GPM stands out as the best overall choice for large households that need reliable, continuous hot water. Its 7.0 GPM flow rate surpasses many competitors, making it ideal for supporting 2-3 simultaneous showers. Compared with the Noritz NR98SVNG, it offers slightly lower flow but benefits from a more straightforward indoor-only setup, which simplifies installation in standard homes. The advanced safety features and precise temperature control help prevent scalding and ensure comfort, while its high efficiency (0.82 UEF) reduces energy costs. However, it requires professional installation and is limited to indoor use, which could be a hurdle for DIY homeowners or outdoor setups. This pick makes the most sense for families prioritizing capacity and safety with a long-term warranty.
Pros:- Provides continuous hot water for multiple fixtures
- High energy efficiency reduces utility bills
- Space-saving wall-mount design
- Advanced safety features and precise temperature control
Cons:- Requires professional installation
- Limited to indoor installation only
- Initial setup can be complex for DIY users
Best for: Large families or multi-bathroom homes needing reliable, high-capacity hot water.
Not ideal for: Small households or outdoor installations where space or weather-proofing matters.
- Flow Rate:7.0 GPM
- BTU:160,000 BTUs
- Fuel Type:Liquid Propane
- Efficiency:0.82 UEF
- Installation:Indoor, wall-mount
- Warranty:15-year heat exchanger, 5-year parts
Our verdict“This is an excellent choice for large households seeking dependable, energy-efficient hot water with a long warranty, provided professional installation is feasible.”
Rinnai CU160iN Commercial Natural Gas Condensing Tankless Water Heater, Indoor Installation, 9 GPM
The Rinnai CU160iN is tailored for commercial or demanding residential settings that require high flow rates and smart features. Its 9 GPM capacity exceeds most residential models like the Rinnai RSC160iN, making it suitable for busy households or small commercial applications. It incorporates recirculation technology and Wi-Fi monitoring, which help optimize energy use and provide remote control—advantages over simpler models. The multiple venting options offer installation flexibility. However, the higher upfront cost and the need for professional installation could deter typical homeowners. This model is best suited to those who value advanced tech and large capacity, even at a higher price point.
Pros:- High flow rate of 9 GPM supports multiple fixtures
- Smart recirculation technology enhances efficiency
- Wi-Fi monitoring for remote management
- Flexible venting options for various installation environments
Cons:- Higher initial cost
- Professional installation required
- May be more complex to operate for non-technical users
Best for: Commercial settings or large households with high hot water demands and an interest in smart features.
Not ideal for: Small households or budget-conscious buyers seeking straightforward, low-cost units.
- Flow Rate:9 GPM
- Installation Type:Indoor
- Fuel Type:Natural Gas
- Technology:Condensing, Recirculation, Wi-Fi Monitoring
- Warranty:8-year heat exchanger, 5-year parts, 1-year labor
Our verdict“This is the go-to for large-scale or commercial applications that benefit from high capacity and smart technology, with a tradeoff of higher cost and complexity.”
Noritz NR98SVNG 7.5 GPM Indoor/Outdoor Tankless Natural Gas Water Heater
The Noritz NR98SVNG offers versatility by functioning both indoors and outdoors, making it flexible for various installation environments. Its 9.8 GPM flow rate is higher than many residential units, supporting multiple outlets simultaneously. The commercial-grade copper heat exchanger ensures durability and longevity. Compared to the Rinnai CU160iN, this model can be linked with another unit for increased capacity, which is a plus for expanding households. Its heavier weight and the need for a separate valve kit may complicate DIY installation. This unit is best suited for users who need high flow capacity and outdoor versatility but are prepared for a somewhat involved setup process.
Pros:- High flow rate of 9.8 GPM supports multiple outlets
- Durable copper heat exchanger for longevity
- Indoor/outdoor versatility with linkage capability
- Commercial-grade construction
Cons:- Heavy at 54 pounds, challenging for solo installation
- Requires separate valve kit for outdoor setup
- Limited details on energy efficiency
Best for: Homeowners needing outdoor or indoor installation with high capacity and durability.
Not ideal for: Urban apartments or those seeking a lightweight, easy-to-install unit.
- Flow Rate:9.8 GPM
- Heat Exchanger Material:Copper
- Power Source:Natural Gas
- Maximum Temperature:140 °F
- Maximum Pressure:150 psi
- Item Weight:54 pounds
Our verdict“Ideal for large households or outdoor installations demanding durability and high flow, with some extra effort needed for installation.”
Rinnai RSC160iN Smart-Circ Condensing Gas Tankless Water Heater, 9 GPM, Indoor, Natural Gas
The Rinnai RSC160iN introduces intelligent operation with Smart-Circ technology that adapts to your water usage patterns, making it efficient for busy households aiming to cut energy waste. Its 9 GPM flow rate comfortably supports multiple fixtures simultaneously. The compact design saves space and makes it easier to install indoors, unlike larger models such as the Rinnai CU160iN. However, Wi-Fi control requires an additional module, adding to the initial setup cost. Its energy Star qualification underscores its efficiency. This unit is best suited for tech-savvy homeowners seeking smart operation and space savings, willing to invest in the extra modules.
Pros:- Smart-Circ technology learns usage patterns for efficiency
- Compact size fits small spaces
- Supports multiple fixtures simultaneously
- Energy Star qualified for proven efficiency
Cons:- Wi-Fi control needs extra module (sold separately)
- Professional installation recommended
- Limited compatibility details available
Best for: Homeowners who want a space-efficient, energy-smart unit with remote control capabilities.
Not ideal for: Buyers who prefer plug-and-play simplicity or have limited budgets for extra modules.
- Flow Rate:Up to 9 GPM
- BTU:160,000 BTU
- Fuel Type:Natural Gas
- Installation:Indoor
- Energy Star Qualified:Yes
- Venting Options:Multiple
Our verdict“This is a smart, space-saving option for tech-savvy households prioritizing energy efficiency and remote operation, with some added cost for convenience.”
Rinnai RX130iN Condensing Smart Sense Tankless Water Heater
The Rinnai RX130iN offers a compact design with a flow rate of 7.1 GPM, making it suitable for smaller homes or outdoor setups. Its dual fuel support (propane or natural gas) adds flexibility, and the Wi-Fi Smart Sense technology helps monitor and optimize energy use. Compared with the Rinnai RSC160iN, it has a slightly lower flow rate but excels in adaptability with indoor or outdoor installation options. The Quick Flush feature simplifies maintenance, extending lifespan. Its smaller size and energy efficiency make it ideal for limited spaces. However, Wi-Fi control requires a separate module, and outdoor use necessitates Versa Vent, which can add to costs. It’s best for those who need a compact, versatile unit that balances efficiency with flexibility.
Pros:- Compact size saves space
- Supports propane or natural gas
- Wi-Fi compatibility for smart control
- Quick Flush for easy maintenance
Cons:- Wi-Fi module sold separately
- Outdoor installation requires Versa Vent
- Slightly lower flow rate than larger units
Best for: Homeowners seeking a space-efficient, versatile, and energy-smart heater for indoor or outdoor use.
Not ideal for: Large households with very high flow needs or those unwilling to buy extra modules.
- Flow Rate:7.1 GPM
- Gas Type:Propane or Natural Gas
- Efficiency:UEF .97
- Installation Options:Indoor or Outdoor
- Warranty:15-year heat exchanger, 5-year parts/labor
Our verdict“A flexible, efficient choice for smaller or outdoor spaces needing reliable hot water with smart features, with some extra costs for modules and venting.”
ThermoMate Condensing Tankless Water Heater Natural Gas, Up to 5.28 GPM
The ThermoMate condensing tankless water heater stands out for delivering reliable hot water at a flow rate of 5.28 GPM, making it well-suited for small families or couples who need simultaneous showers without sacrificing efficiency. Compared with larger models like the Rheem RTGH Series, it offers a more space-friendly footprint while maintaining high energy efficiency, thanks to its dual heat exchanger design. However, its modest flow rate limits its suitability for larger households or high-demand applications. The smart LED touchscreen simplifies operation, but users should be aware that the condensate neutralizer kit is not included and requires an additional purchase. Proper venting and drainage setup are essential, which can add to installation complexity. Maintenance needs, especially for condensate drainage, could be a concern over time.
This pick makes the most sense for small households prioritizing space efficiency, energy savings, and modern controls.
Pros:- Compact size ideal for limited space installations
- High energy efficiency with dual heat exchanger design
- Smart LED touchscreen for intuitive control and monitoring
- Capable of servicing two showers simultaneously
Cons:- Condensate neutralizer kit sold separately adds to initial cost
- Flow rate may be insufficient for high-demand households
- Requires careful venting and drainage setup, which can be complex
Best for: Small families or couples living in apartments or small homes who want a compact, efficient unit with easy controls
Not ideal for: Large households or homes with multiple bathrooms, where higher flow rates are necessary and this model’s 5.28 GPM may be insufficient
- Flow Rate:5.28 GPM
- BTU:114,000 BTU
- Efficiency:0.86 UEF
- Water Temperature Range:90°F to 140°F
- Dimensions:21″H x 13″W x 7″D
- Voltage:120V
- Gas Inlet:1/2″ NPT
- Water Inlet/Outlet:3/4″ NPT
- Vent Diameter:3″ OD
Our verdict“This unit is best suited for small households seeking space-saving, efficient hot water with modern controls, but it may fall short for larger families with higher demand needs.”
How We Picked
The products in this roundup were evaluated based on performance, efficiency, build quality, ease of installation, and value. Priority was given to models that deliver consistent hot water flow, especially at high demand, while maintaining condensing technology for energy savings. We also considered user-friendly features, reliability, and manufacturer reputation. Rankings reflect a balance between affordability and premium features, ensuring options suit different budgets and needs. Models with advanced safety features and smart controls earned higher marks, as these add practical value and peace of mind for users.Factors to Consider When Choosing Best Tankless Gas Water Heater Condensing
Choosing the best tankless gas water heater condensing unit involves understanding key factors that influence performance, cost, and usability. Beyond brand reputation, buyers should consider the unit’s capacity, efficiency ratings, venting requirements, and installation complexity. Recognizing how these elements interact helps prevent common mistakes like under-sizing or overspending on unnecessary features. A thoughtful selection ensures reliable hot water supply while optimizing energy savings and long-term costs.Capacity and Flow Rate
Matching the unit’s GPM (gallons per minute) to your household’s peak hot water demand is essential. A unit that’s too small may struggle during busy mornings, while an oversized model could waste energy and increase upfront costs. Consider the number of fixtures and appliances that will run simultaneously when choosing capacity. For larger homes or busy households, selecting a model with a higher GPM provides peace of mind and consistent hot water flow.
Efficiency and Energy Savings
Condensing technology is designed to recover more heat from exhaust gases, significantly reducing energy consumption. Look for models with high thermal efficiency ratings (above 90%) to maximize savings. Keep in mind that higher efficiency units may come with a higher purchase price but tend to pay off over time through lower utility bills. Be aware that some units also feature eco-friendly emissions, which can be a key factor in environmentally conscious decisions.
Venting and Installation Requirements
Proper venting is critical for safety and performance, especially with condensing units that generate condensate. Some models require specialized venting systems, which can add to installation complexity and costs. Evaluate your home’s existing venting infrastructure and consider the ease of installation. Incorrect or inadequate venting can lead to issues like carbon monoxide leaks or decreased efficiency, so it’s worth investing in professional installation for these systems.
Size and Space Considerations
Tankless units vary in size, and space constraints often influence the choice. Compact models are ideal for small utility closets or limited spaces, but they may have lower capacity or fewer features. Larger units, while bulkier, typically support greater flow rates and additional safety or control features. Measure your available space carefully and choose a model that fits comfortably without sacrificing performance.
Smart Features and Controls
Advanced models now incorporate Bluetooth, Wi-Fi, or digital controls for easier management and customization. Smart features enable remote diagnostics, scheduling, and usage monitoring, which can enhance convenience and maintenance. However, these features often come with a higher price tag and potential compatibility issues. Decide if smart controls align with your tech preferences and budget, or if a simpler model suffices.
Frequently Asked Questions
Can a condensing tankless gas water heater work efficiently in cold climates?
Yes, many condensing tankless gas water heaters are designed to operate efficiently in cold climates. They typically feature advanced heat exchangers and insulation to maintain performance despite low outdoor temperatures. However, installation considerations such as proper venting and ensuring adequate gas supply are vital for optimal operation. Choosing a model with a high flow rate and proven cold-weather performance can help ensure reliable hot water supply year-round.
Is it necessary to have a professional install a condensing tankless gas water heater?
Professional installation is highly recommended for condensing tankless gas water heaters due to their venting and gas connection requirements. Proper setup ensures safe operation, optimal efficiency, and compliance with local codes. Incorrect installation can lead to safety hazards or reduced lifespan, so investing in qualified HVAC or plumbing services is a wise choice for peace of mind and reliable performance.
How often do condensing tankless water heaters require maintenance?
Regular maintenance for condensing units typically involves flushing out mineral build-up, inspecting venting, and checking safety features. Most manufacturers recommend annual or semi-annual inspections to ensure efficient operation and longevity. Maintaining the condensate drain and ensuring proper venting also prevent potential issues. Routine upkeep can extend the life of the unit and maintain energy efficiency over time.
Are condensing tankless water heaters more energy-efficient than non-condensing models?
Yes, condensing models generally outperform non-condensing units in energy efficiency due to their ability to reclaim heat from exhaust gases. This process boosts thermal efficiency into the 90% range, translating into lower energy bills. However, they often have higher upfront costs and more complex venting requirements. The long-term savings usually justify the initial investment for most homeowners seeking eco-friendly options.
What should I consider when choosing between natural gas and propane models?
The decision hinges largely on your available fuel source and local utility prices. Natural gas models are typically more economical if you have a gas line, but propane units can be a good alternative in areas without access to natural gas. Consider the unit’s BTU rating and your household’s hot water needs. Also, check the installation costs, as propane units may require additional components for safe operation and venting.
Conclusion
For most households seeking a reliable, high-efficiency system, the Rinnai V53DeN offers an excellent balance of capacity, durability, and value, earning the spot as the best overall. Budget-conscious buyers should consider the ThermoMate for its affordability, while those ready to invest in advanced features and the highest efficiency will find the Noritz GQ-C3261WX-FF a worthwhile choice. First-time buyers or those with limited space might prefer the compact models like the Noritz NR98SVNG. Ultimately, selecting the right unit depends on your household size, budget, and specific needs, but understanding these distinctions helps make a confident decision.
