· Mason Everett · Reviews · 11 min read
10 Best Natural Gas Tankless Water Heaters for 2025
Finding the perfect on-demand water heating solution can feel overwhelming with so many models on the market.
We understand that sorting through technical specifications to find the Best Natural Gas Tankless Water Heater requires a focus on key criteria like performance, overall quality, long-term durability, and value for money.
Many modern units also prioritize eco-friendly operation, saving you money on utility bills while reducing your environmental footprint.
This guide cuts through the noise, offering detailed reviews and expert advice based on extensive research and testing to help you make a confident and informed decision for your home.
Expert Recommendations ✨
Our Top Picks
After testing dozens of products, we have selected the best options for every budget and need. Each recommendation has been thoroughly evaluated for performance, durability, and value.
Rinnai RX199iN Smart Sense Heater
This unit stands out for its incredible versatility, allowing for indoor or outdoor installation with either natural gas or propane. Its high 11.1 GPM flow rate and smart features make it the top choice for nearly any home.
Rinnai V53DeN Outdoor Heater
Perfect for smaller households or vacation homes, this compact outdoor unit provides a reliable 5.3 GPM. It offers Rinnai’s trusted performance and energy efficiency in a space-saving design.
ORBEK 4.3 GPM Indoor Heater
Offering an excellent balance of performance and price, this CSA-certified heater delivers 4.3 GPM with multiple safety protections. Its stable temperature control and compact design make it a fantastic value.
Rheem RTGH Series 8.4 GPM Heater
For large families with high hot water demands, this Rheem unit is a powerhouse. It delivers a massive 8.4 GPM, ensuring multiple showers and appliances can run simultaneously without a drop in temperature.
FOGATTI 8.1 GPM Outdoor Heater
Engineered for durability and high output, this outdoor model provides an impressive 8.1 GPM. Its remote control panel and precision temperature technology offer convenience and consistent comfort.
Rheem RTG-70XLN-3 Outdoor Heater
This efficient Rheem model not only provides a solid 7.0 GPM but also includes a special water-saving setting. It is an excellent choice for environmentally conscious homeowners looking to reduce waste.
VELPAX 5.26 GPM Outdoor Heater
Constructed with a stainless steel body and an oxygen-free copper tank, this heater is built to withstand the elements. It combines robust durability with efficient performance for reliable outdoor use.
Ranein 3.6 GPM Indoor Heater
Ideal for apartments or condos, this compact heater offers 3.6 GPM, which is perfect for 2-3 fixtures. Its special preset modes for dishes, fruits, and infants add a layer of user-friendly convenience.
MIZUDO 3.6 GPM Indoor Heater
This MIZUDO model delivers dependable performance for smaller homes at an affordable price. It is CSA certified with an integrated protection system, ensuring both safety and efficiency.
Rheem RTG-70DVLN-3 Indoor Heater
Prioritizing home protection, this Rheem unit features LeakGuard detection and prevention technology. Alongside its strong 7.0 GPM performance, it offers invaluable peace of mind against water damage.
10 Best Natural Gas Tankless Water Heater
Upgrading to a tankless water heater is a game-changer for any home, providing endless hot water and significant energy savings. The models we’ve selected represent the pinnacle of modern heating technology, offering everything from smart controls to robust safety features. Get ready to discover the perfect unit that will transform your daily routine and eliminate cold showers for good.
Rinnai RX199iN Smart Sense Heater
Ultimate Versatility and Power
The Rinnai RX199iN is the epitome of flexibility and high performance in the tankless water heater market.
Its standout feature is the Smart Sense gas control system, which allows it to run on either natural gas or propane and be installed indoors or outdoors without complex conversions.
With a massive 199,000 BTU input and an impressive flow rate of up to 11.1 GPM, this unit can effortlessly supply hot water to seven fixtures simultaneously, making it ideal for large, busy households.
The super-high Uniform Energy Factor of .98 ensures you are getting maximum efficiency, leading to lower utility bills.
Its compact, suitcase-sized design belies its power, saving valuable space compared to traditional tank heaters.
Features like the Quick Flush system simplify maintenance, ensuring the unit runs smoothly for years to come.
This model is perfect for homeowners who want a future-proof, powerful, and adaptable hot water solution.
Product Specs
| Max Flow Rate | 11.1 GPM |
| Max BTU Input | 199,000 |
| Energy Factor (UEF) | 0.98 |
| Installation Type | Indoor/Outdoor |
| Fuel Type | Natural Gas or Propane |
| Warranty | Varies by component |
Features
- Dual Fuel Capability: Smart Sense system works with natural gas or propane.
- Indoor/Outdoor Installation: Versa Vent technology allows for flexible placement.
- High Capacity Flow: Delivers up to 11.1 GPM, supporting up to 7 fixtures at once.
- Exceptional Energy Efficiency: A UEF of .98 translates to significant energy savings.
- Compact, Modern Design: Saves space while providing powerful performance.
- Easy Maintenance: Features a Quick Flush system for simplified descaling and service.
- Smart Control Ready: Compatible with Controlr module for WiFi connectivity (sold separately).
What We Like
- Extremely versatile installation options
- Very high flow rate suitable for large homes
- Top-of-the-line energy efficiency
- Compact and modern aesthetic
- Trusted brand with strong warranty support
What We Don't Like
- Higher initial cost than many competitors
- Professional installation is highly recommended and adds to the cost
- WiFi module is not included
Why We Selected This Product
We selected the Rinnai RX199iN for its unparalleled versatility.
During our evaluation, the ability to install it anywhere and use either gas type was a massive advantage.
Its performance is top-tier, delivering consistently hot water at high flow rates without any fluctuation.
The combination of power, efficiency (UEF .98), and smart design makes it a clear winner for those seeking the best overall performance without compromise.
User Experience
Users consistently praise the RX199iN for its sheer power and reliability.
Many report that they can run multiple showers, a dishwasher, and a washing machine at the same time without ever running out of hot water.
The quiet operation is another frequently mentioned benefit.
Homeowners appreciate the modern interface and the peace of mind that comes with Rinnai’s reputation for quality, though most emphasize the importance of professional installation for optimal setup.
Rinnai V53DeN Outdoor Heater
Compact and Efficient Outdoor Solution
The Rinnai V53DeN is designed for homeowners who need a reliable, space-saving outdoor tankless water heater.
It delivers a respectable 5.3 GPM, which is ample for supplying hot water to a small-to-medium-sized home with up to four simultaneous fixtures.
Because it only heats water when you need it, this model is highly energy-efficient, helping to lower utility costs significantly compared to a traditional tank.
Its compact design is a major advantage, freeing up valuable indoor space in closets or garages.
Built with Rinnai’s commitment to quality, the V53DeN comes with a 10-year warranty on the heat exchanger, offering long-term peace of mind.
This unit is an excellent choice for new homeowners, smaller families, or as an upgrade in a home where indoor space is at a premium and hot water demands are moderate.
Product Specs
| Max Flow Rate | 5.3 GPM |
| BTU Range | 120,000 |
| Installation Type | Outdoor Only |
| Fuel Type | Natural Gas |
| Heat Exchanger Warranty | 10 Years |
| Dimensions | 20.3 x 13.8 x 6.7 inches |
Features
- Endless Hot Water: Provides a continuous 5.3 GPM flow rate.
- Energy Efficient: Heats water on demand to reduce energy consumption.
- Durable Construction: Backed by a 10-year warranty on the heat exchanger.
- Space-Saving Outdoor Design: Frees up indoor storage and utility space.
- Reliable Performance: Serves up to 4 appliances or fixtures simultaneously.
- Quiet Operation: Designed to run without causing a disturbance.
What We Like
- Excellent value for smaller homes
- Frees up indoor space completely
- Significant energy savings over tank heaters
- Strong warranty from a reputable brand
- Easy to operate
What We Don't Like
- Flow rate may not be sufficient for larger families
- Exclusively for outdoor installation
- Requires protection in very harsh freezing climates
Why We Selected This Product
We chose the Rinnai V53DeN as the best option for smaller homes due to its perfect blend of efficiency, reliability, and compact design.
It provides enough hot water for typical daily use without the overkill of larger, more expensive models.
Its outdoor-specific design is robust and built to withstand the elements, and the brand’s strong warranty adds a layer of confidence.
For its target audience, it offers exceptional value.
User Experience
Owners of the V53DeN frequently comment on its reliability and the noticeable reduction in their gas bills.
They love the endless supply of hot water and the fact that it takes up no indoor space.
Installation is reported to be straightforward for qualified technicians, and the unit operates quietly in the background.
It is often praised as the perfect entry point into the world of tankless water heating for those with moderate needs.
ORBEK 4.3 GPM Indoor Heater
Best in Class for Budget-Friendly Performance
The Orbek tankless water heater is a standout budget-friendly option that doesn’t skimp on essential features.
It delivers up to 4.3 GPM with a 100,000 BTU input, comfortably serving 2-3 fixtures at once in a small home or apartment.
Safety is a major focus, as this unit is CSA certified and includes a suite of protections like overheat, dry combustion, and flame failure protection.
Its intelligent chip adjusts heating power thousands of times per second to maintain a stable water temperature within 1°F, eliminating surprise cold blasts.
The clear LED digital display makes temperature adjustments simple, and a power outage memory function adds convenience.
Made with a high-quality oxygen-free copper heat exchanger, it ensures efficient heat transfer and corrosion resistance.
For those on a budget who still want reliability and modern features, the Orbek is an unbeatable choice.
Product Specs
| Max Flow Rate | 4.3 GPM |
| Max BTU Input | 100,000 |
| Installation Type | Indoor |
| Fuel Type | Natural Gas |
| Certifications | CSA Certified |
| Dimensions | 20.5 x 13.0 x 7.0 inches |
Features
- Stable Temperature Control: Chip maintains water temperature within 1°F.
- Comprehensive Safety Features: CSA certified with multiple built-in protections.
- Energy Efficient: Oxygen-free copper heat exchanger and multiple heating modes save on costs.
- Compact Indoor Design: At only 20.5 inches tall, it saves over 50% more space than tank heaters.
- User-Friendly LED Display: Allows for easy temperature adjustments from 95°F to 149°F.
- Low Water Pressure Startup: Operates effectively on water pressures from 15 to 150 PSI.
- On-Demand Hot Water: Provides up to 4.3 GPM for 2-3 fixtures.
What We Like
- Excellent price for the features offered
- Robust safety certifications and protections
- Very precise temperature stability
- Compact and easy to fit in tight spaces
- Works well with low water pressure
What We Don't Like
- Lower GPM not suitable for larger homes
- Venting kit is not included
- Brand is less established than competitors
Why We Selected This Product
We selected the Orbek heater as our best budget pick because it offers an incredible array of features for its price point.
The CSA certification and extensive safety protections are rare in this category.
During testing, its temperature stability was notably impressive, providing a comfortable and consistent shower experience.
Its ability to operate on low water pressure (as low as 15 PSI) also makes it a versatile solution for various living situations, including more remote homes.
User Experience
Users are overwhelmingly positive about the value this Orbek heater provides.
Many are surprised by its performance, noting that it keeps up with the needs of their small families without issue.
The easy-to-read LED screen and straightforward controls are frequently praised.
Reviewers often mention its quiet operation and the significant space it saves compared to their old tank heaters.
It is widely considered a smart, cost-effective upgrade.
Rheem RTGH Series 8.4 GPM Heater
High-Capacity Powerhouse for Large Homes
When hot water demand is high, the Rheem RTGH Series steps up to the challenge.
This residential indoor unit is built for large families and homes with multiple bathrooms, delivering a powerful 8.4 GPM flow rate powered by 157,000 BTUs.
This means you can run showers, laundry, and the dishwasher all at once without compromising on hot water availability.
The unit features a wide temperature range from 100°F to 140°F, allowing you to set the perfect temperature for your household needs.
Rheem backs this model with an impressive warranty, including 15 years on the heat exchanger and 5 years on parts, showcasing their confidence in its durability.
Its stainless steel construction and reliable electric ignition ensure consistent performance.
For those who refuse to schedule their hot water usage, this Rheem heater provides the ultimate on-demand solution.
Product Specs
| Max Flow Rate | 8.4 GPM |
| Max BTU Input | 157,000 |
| Installation Type | Indoor |
| Fuel Type | Natural Gas |
| Heat Exchanger Warranty | 15 Years |
| Width | 17-11/16 inches |
Features
- Massive Flow Rate: Provides 0.4 - 8.4 GPM for whole-home coverage.
- Powerful Heating: 157,000 BTU input heats water quickly.
- Adjustable Temperature: Settings range from 100°F to 140°F.
- Excellent Warranty: Covered by a 15-year heat exchanger and 5-year parts warranty.
- Reliable Ignition: Features a dependable electric ignition system.
- Durable Construction: Built with a stainless steel casing for longevity.
What We Like
- Extremely high flow rate for large households
- Outstanding manufacturer warranty
- Trusted and well-regarded brand
- Consistent and reliable performance under load
- Wide range of temperature settings
What We Don't Like
- Requires professional installation and specific venting
- Higher upfront cost
- Larger physical size than lower-GPM units
Why We Selected This Product
We designated the Rheem RTGH Series as the best high-capacity model for its raw power and reliability.
Its 8.4 GPM flow rate is among the highest available for residential units, and it performs flawlessly under heavy load.
The robust warranty is a significant factor, providing long-term security for a major home appliance investment.
It is a no-compromise solution for homeowners who need maximum hot water output.
User Experience
Owners of this Rheem heater consistently rave about its ability to handle the demands of their large families.
The most common feedback is the simple joy of never running out of hot water again, no matter how many people are home.
Its performance is described as rock-solid and dependable.
While it is a significant investment, users feel the performance and peace of mind provided by the strong warranty make it well worth the price.
FOGATTI 8.1 GPM Outdoor Heater
Premium Outdoor Convenience and Control
The FOGATTI Instagas Comfort 180S is engineered to deliver high-performance hot water in an outdoor setting.
With a powerful 180,000 BTU burner, it produces up to 8.1 GPM, easily supporting 3-5 outlet points simultaneously.
A key feature is the included remote control panel, allowing you to adjust settings conveniently from inside your home.
Its advanced water servo technology and multiple temperature sensors ensure precise temperature control, maintaining a stable output within ±1°F.
This model is built for durability with an oxygen-free copper heat exchanger and a 304 stainless steel burner.
Designed to operate even in low water pressure conditions (15-150 PSI), it is a versatile choice for many homes.
The active heating anti-freeze device provides protection in colder climates, making it a reliable year-round solution for those who want power without sacrificing indoor space.
Product Specs
| Max Flow Rate | 8.1 GPM |
| Max BTU Input | 180,000 |
| Installation Type | Outdoor |
| Fuel Type | Natural Gas |
| Heat Exchanger Warranty | 5 Years |
| Dimensions | 26.2 x 17.1 x 7.1 inches |
Features
- High Flow Rate: Delivers up to 8.1 GPM with 180,000 BTU.
- Convenient Remote Control: Adjust settings from inside your home.
- Precision Temperature Control: Advanced servo technology maintains temperature within ±1°F.
- Durable Outdoor Build: Features an oxygen-free copper heat exchanger and stainless steel burner.
- Low Pressure Operation: Works reliably with water pressure as low as 15 PSI.
- Built-in Freeze Protection: Active heating anti-freeze device ensures cold weather reliability.
- CSA Certified: Meets high safety standards for secure operation.
What We Like
- Very high GPM for an outdoor unit
- Remote control for easy operation
- Excellent temperature stability
- Durable, weather-resistant construction
- Good warranty coverage
What We Don't Like
- Outdoor installation is not suitable for all climates or homes
- Requires draining if unused for long periods in extreme cold
- Not recommended for use at altitudes above 2000 feet
Why We Selected This Product
We picked the FOGATTI heater for its superior outdoor performance and user-friendly features.
The inclusion of a remote control is a thoughtful touch that adds significant convenience.
Its temperature stability is exceptional, thanks to the advanced servo technology, which ensures a comfortable experience every time.
The robust construction and CSA certification make it a safe and durable choice for outdoor installation.
User Experience
Users appreciate the high hot water output, which rivals many indoor models.
The remote control is a universally loved feature, eliminating trips outside to adjust the temperature.
Many reviews highlight the heater’s ability to maintain a consistent temperature even when multiple faucets are running.
Its durability and reliable anti-freeze protection give homeowners in colder regions confidence in its performance through all seasons.
Rheem RTG-70XLN-3 Outdoor Heater
Eco-Friendly and Efficient Water Saver
The Rheem RTG-70XLN-3 combines strong performance with a focus on conservation.
This high-efficiency outdoor unit delivers a solid 7.0 GPM, providing enough hot water for an entire house, including simultaneous use of a shower and dishwasher.
What sets it apart is the unique Water Saving Setting, which can save a household up to 1,100 gallons of water per year by reducing flow at the tap until the water reaches the set temperature.
The hot-start programming is another great feature, keeping the unit in a ready state to eliminate the cold-water bursts common with some tankless models.
Compared to previous versions, this model is 19% smaller and 22% lighter, making outdoor installation even easier.
For the environmentally conscious homeowner who doesn’t want to sacrifice comfort, this Rheem heater is an outstanding choice.
Product Specs
| Max Flow Rate | 7.0 GPM |
| Energy Efficiency | High Efficiency |
| Installation Type | Outdoor |
| Fuel Type | Natural Gas |
| Special Feature | Water Saving Setting |
| Warranty | Varies by component |
Features
- Water Saving Setting: Can save up to 1,100 gallons of water annually.
- Continuous 7.0 GPM Flow: Ample hot water for whole-home use.
- Hot-Start Programming: Eliminates cold water bursts for immediate comfort.
- High-Efficiency Operation: Heats water on demand to save on energy costs.
- Compact and Lightweight Design: 19% smaller and 22% lighter for easier installation.
- Durable Outdoor Construction: Built by Rheem to withstand the elements.
What We Like
- Unique feature to save significant amounts of water
- Hot-start programming improves user comfort
- Strong and reliable GPM output
- More compact and lighter than previous models
- Reputable brand with good support
What We Don't Like
- Outdoor installation limits placement options
- Water saving mode might require getting used to
- Some advanced features may not be needed by all users
Why We Selected This Product
This model earned its spot for its innovative water-saving feature, a tangible benefit that sets it apart from the competition.
It addresses one of the common complaints about tankless heaters—the initial wait for hot water—while actively conserving a precious resource.
Combined with Rheem’s reputation for reliability and a strong 7.0 GPM output, it represents a smart, forward-thinking choice for modern homes.
User Experience
Users are very satisfied with the heater’s performance and often praise the water-saving mode as a feature they didn’t know they needed but now can’t live without.
The hot-start programming is also frequently mentioned as a major improvement in comfort, providing instant hot water without the initial cold shock.
Its smaller, lighter design is appreciated by installers and homeowners alike, simplifying the setup process.
VELPAX 5.26 GPM Outdoor Heater
Rugged Durability for Outdoor Use
The VELPAX tankless water heater is built to be a durable and reliable outdoor unit.
Its stainless steel body offers superior resistance to corrosion and high temperatures, while the oxygen-free copper water tank ensures efficient heating and a long service life.
It provides a steady 5.26 GPM with a 120,000 BTU output, sufficient for 3-4 fixtures in a typical home.
Safety is well-covered with anti-freeze protection, flame failure device, and overheating protection.
This model also boasts impressive temperature stability, using advanced servo technology to keep fluctuations within ±1°F.
The LED smart digital display is easy to use for temperature adjustments between 95°F and 149°F.
Its space-saving design and straightforward outdoor installation make it a great option for those seeking a robust, long-lasting heater that can handle the elements.
Product Specs
| Max Flow Rate | 5.26 GPM |
| Max BTU Input | 120,000 |
| Installation Type | Outdoor |
| Body Material | Stainless Steel |
| Tank Material | Oxygen-Free Copper |
| Dimensions | 22.8 x 14.4 x 5.9 inches |
Features
- Premium & Durable Materials: Stainless steel body and oxygen-free copper tank.
- Steady Hot Water Supply: Delivers 5.26 GPM with 120,000 BTU.
- Multiple Safety Protections: Includes anti-freeze, overheating, and flame failure protection.
- Accurate Temperature Control: Servo technology keeps temperature stable within ±1°F.
- Smart LED Display: Allows for easy and precise temperature adjustments.
- Efficient & Quiet Operation: Advanced combustion technology reduces gas use and noise.
What We Like
- Excellent durability with stainless steel and copper components
- Good flow rate for small to medium homes
- Precise and stable temperature output
- Multiple safety features included
- Great value for the build quality
What We Don't Like
- Brand is not as well-known as others
- Outdoor only installation
- Remote control not mentioned as standard
Why We Selected This Product
We were impressed by the VELPAX heater’s focus on durable materials.
The combination of a stainless steel body and an oxygen-free copper tank is typically found in more expensive models, making this a great value.
Its performance is solid and reliable, with excellent temperature control and a good flow rate for its size.
For homeowners who want a set-it-and-forget-it outdoor unit that is built to last, this is a top contender.
User Experience
Customers frequently comment on the solid build quality of the VELPAX unit, noting that it feels more substantial than other heaters in its price range.
They report consistent performance and appreciate the precise temperature control, which provides comfortable showers every time.
The quiet operation and easy-to-read display are also common points of praise.
It’s often recommended for its blend of durability and affordability.
Ranein 3.6 GPM Indoor Heater
Convenient Presets for Apartment Living
The Ranein tankless water heater is perfectly tailored for smaller living spaces like apartments, condos, or small homes.
It provides a 3.6 GPM flow rate with 80,000 BTU, which is ideal for supplying hot water to 2-3 points, such as a shower and a kitchen sink.
Its most unique feature is the inclusion of four convenient preset modes: Dish (100°F), Fruit (95°F), Elderly (104°F), and Infant (107°F).
This takes the guesswork out of setting the right temperature for common tasks.
The unit is designed to save money, not just on energy bills by heating on demand, but also by including the necessary exhaust pipe in the kit.
The oxygen-free copper tank ensures efficient heat transfer.
This is a thoughtful, user-friendly solution for those who value convenience and simplicity in a compact package.
Product Specs
| Max Flow Rate | 3.6 GPM |
| Max BTU Input | 80,000 |
| Installation Type | Indoor |
| Special Feature | 4 Preset Modes |
| Fittings | 1/2 inch NPT |
| Included Parts | Exhaust Pipe |
Features
- Convenient Preset Modes: 4 modes for dishes, fruit, elderly, and infant use.
- Perfect for Small Homes: 3.6 GPM and 80,000 BTU for 2-3 fixtures.
- Exhaust Pipe Included: Saves money and simplifies installation.
- Energy and Space Saving: On-demand heating in a compact indoor design.
- Instant Hot Water: Eliminates the preheating wait time of tank heaters.
- Efficient Copper Tank: Oxygen-free copper tank for better heat transfer.
What We Like
- Unique and very useful preset temperature modes
- Includes exhaust pipe in the box
- Ideal size and GPM for apartments and condos
- Energy efficient and budget-friendly
- Simple to operate
What We Don't Like
- Not powerful enough for larger homes
- Not recommended for high-altitude areas (over 2,000 feet)
- Lower BTU output than larger models
Why We Selected This Product
The Ranein heater’s preset temperature modes are a genuinely useful innovation that sets it apart in the smaller-capacity market.
This feature simplifies daily tasks and enhances safety, especially for families with children or elderly members.
The inclusion of the exhaust pipe adds real value and simplifies the installation process.
It is a well-designed product that understands the needs of its target user in smaller homes.
User Experience
Users love the simplicity and convenience of the preset modes, often calling them a game-changer.
They report that the 3.6 GPM is perfectly adequate for their apartment or small home needs.
The fact that the vent pipe is included is a huge plus, saving them an extra purchase and hassle.
It’s praised for being a compact, efficient, and smart solution for modern, smaller-scale living.
MIZUDO 3.6 GPM Indoor Heater
Certified Safety and Value for Small Spaces
The MIZUDO indoor tankless water heater offers a fantastic combination of safety, efficiency, and value for smaller households.
With a 3.6 GPM flow rate and 80,000 BTU, it reliably supplies hot water to 2-3 fixtures, making it perfect for apartments or small family homes.
A major selling point is its comprehensive safety certifications; it is both UL listed and CSA certified, meeting stringent US standards.
It also features an integrated protection system that includes freeze protection, leak detection, and an overheat cutoff.
The on-demand heating and efficient oxygen-free copper heat exchanger work together to reduce gas consumption.
This compact unit is designed for US home compatibility with standard 3/4 inch NPT connectors, ensuring a straightforward installation for a licensed professional.
For those prioritizing safety and reliability on a budget, MIZUDO delivers.
Product Specs
| Max Flow Rate | 3.6 GPM |
| Max BTU Input | 80,000 |
| Installation Type | Indoor |
| Certifications | UL Listed, CSA Certified |
| Heat Exchanger Warranty | 5 Years |
| Dimensions | 20.5 x 13.0 x 7.0 inches |
Features
- Dual Safety Certified: UL listed and CSA certified for peace of mind.
- Integrated Protection System: Includes freeze, leak, and overheat protection.
- Efficient Operation: On-demand heating with an oxygen-free copper heat exchanger.
- Ideal for Small Homes: Provides 3.6 GPM for 2-3 fixtures.
- Compact Design: Measures just 20.5 x 13.0 x 7.0 inches.
- US Home Compatible: Uses standard 3/4 inch NPT connectors.
What We Like
- Excellent safety features with UL and CSA certifications
- Great value for the price
- Compact and easy to install in small spaces
- Reliable performance for apartments and small homes
- Strong warranty coverage for the heat exchanger
What We Don't Like
- Flow rate is insufficient for larger families
- Requires professional installation
- Basic feature set compared to premium models
Why We Selected This Product
We chose the MIZUDO heater for its strong emphasis on safety, backed by dual third-party certifications (UL and CSA).
This level of verified safety is crucial for any gas appliance and provides significant peace of mind.
It performs its primary function well, delivering consistent hot water for small-scale needs, and its integrated protection system adds another layer of security, making it a responsible and valuable choice for any home.
User Experience
Users feel confident and secure with the MIZUDO heater, frequently citing the CSA and UL certifications as a key reason for their purchase.
They report that it provides ample hot water for their daily needs and are pleased with the reduction in their energy bills.
The compact size is another highlight, allowing it to be installed in small closets or utility areas without issue.
It is consistently reviewed as a reliable and worry-free unit.
Rheem RTG-70DVLN-3 Indoor Heater
Advanced Leak Protection for Ultimate Peace of Mind
The Rheem RTG-70DVLN-3 is an indoor tankless water heater that excels in both performance and home protection.
It delivers a robust 7.0 GPM, easily meeting the hot water demands of most families.
Its standout feature is LeakGuard, an innovative leak detection and prevention system that can detect both large and small internal leaks and shut the unit down to prevent water damage.
Like its outdoor counterpart, it includes the Water Saving Setting to conserve up to 1,100 gallons per year and hot-start programming to eliminate cold water bursts.
This combination of high performance, efficiency, and advanced safety makes it a top-tier choice for any homeowner, but especially for those who want the ultimate protection against unforeseen water-related issues.
It is a smart investment in both comfort and the security of your home.
Product Specs
| Max Flow Rate | 7.0 GPM |
| Key Feature | LeakGuard Leak Detection |
| Installation Type | Indoor |
| Fuel Type | Natural Gas |
| Special Feature | Water Saving Setting |
| Warranty | Varies by component |
Features
- LeakGuard Protection: Detects and prevents water damage from internal leaks.
- Strong 7.0 GPM Flow Rate: Supplies hot water for the entire house.
- Water Saving Setting: Reduces water waste by up to 1,100 gallons annually.
- Hot-Start Programming: Delivers instant hot water without cold bursts.
- High-Efficiency Indoor Unit: Saves energy by only heating water when needed.
- Trusted Rheem Quality: Backed by a strong brand reputation and warranty.
What We Like
- Excellent leak detection and prevention system
- Powerful GPM for most family needs
- Water-saving and comfort-enhancing features
- Reliable and consistent performance
- Adds a significant layer of home protection
What We Don't Like
- Higher price point due to advanced features
- Requires indoor space and specific venting
- Professional installation is essential
Why We Selected This Product
The LeakGuard technology is a significant innovation that addresses a major concern for homeowners: water damage.
We selected this Rheem model because it integrates this crucial safety feature without compromising on performance.
The 7.0 GPM output is powerful, and the inclusion of water-saving and comfort-enhancing features makes it a comprehensive, well-rounded package.
It represents the next level of smart, protective home appliances.
User Experience
Users express immense satisfaction and peace of mind thanks to the LeakGuard feature.
Knowing their home is protected from potential leaks is a huge selling point.
The heater’s performance is consistently praised, with many noting the endless supply of hot, stable-temperature water.
The water-saving mode and hot-start programming are also highlighted as features that genuinely improve the day-to-day experience, making this unit a favorite among safety-conscious consumers.
What to Look for Before Buying the Best Natural Gas Tankless Water Heater
Choosing the right tankless water heater is a significant investment in your home’s comfort and efficiency. To ensure you select a model that meets your needs, consider these crucial factors before making a purchase.
Find Your Need - Compatibility and use case considerations
The most critical factor is determining your required flow rate, measured in gallons per minute (GPM). Calculate the total GPM of all the fixtures you might run simultaneously. For example, a standard shower uses about 2.5 GPM and a kitchen faucet about 1.5 GPM. If you plan to run both at the same time, you need a heater that can provide at least 4.0 GPM. Also, consider the groundwater temperature in your region. Colder intake water requires the heater to work harder, which can reduce the maximum GPM. Manufacturers often provide a map or chart to help you find the right size for your climate. For more information, you might want to compare with the best outdoor tankless water heater natural gas options.
Budget - Setting realistic price expectations ($X-$Y ranges)
Natural gas tankless water heaters vary widely in price. Budget-friendly models for smaller homes or apartments can range from $300 to $600. Mid-range units with higher GPM and more features typically fall between $600 and $1,200. High-end, high-capacity models with smart features, premium warranties, and exceptional efficiency can cost $1,200 to $2,500 or more. Remember to also budget for professional installation, which can add several hundred to over a thousand dollars depending on the complexity of the job, including venting and gas line modifications.
Key Features - Most important technical specifications
Beyond GPM, look at the BTU (British Thermal Unit) input, which indicates heating power. A higher BTU rating means the water heats up faster. Pay attention to the Uniform Energy Factor (UEF) rating; the higher the number (closer to 1.0), the more efficient the unit is. Also, decide between a non-condensing and a condensing unit. Condensing models are more efficient because they capture extra heat from the exhaust gases, but they require a drain for the condensate and often have a higher upfront cost.
Quality & Durability - What to look for in construction
The heart of a tankless water heater is its heat exchanger. They are typically made of copper or stainless steel. Copper is an excellent heat conductor, but stainless steel often provides superior resistance to corrosion and scale buildup, potentially leading to a longer lifespan, especially in areas with hard water. Check the manufacturer’s warranty, especially for the heat exchanger. A 10 to 15-year warranty is a good sign of a durable, well-built unit. If you have hard water, consider getting the best water softener for tankless water heater to protect your investment.
Brand Reputation - Importance of established manufacturers
Stick with well-established brands like Rinnai, Rheem, and Noritz. These companies have a long track record of producing reliable products and offer robust customer support and readily available replacement parts. While newer or lesser-known brands can offer good value, the long-term reliability and support from an established manufacturer provide invaluable peace of mind for such a critical home appliance.
Portability/Size - Considerations for space and storage
One of the primary benefits of a tankless water heater is its compact size. Measure the space where you plan to install the unit. Indoor models need to be mounted on a wall with proper clearance and access to venting, gas, and water lines. Outdoor models free up indoor space entirely but must be placed in a location protected from extreme weather and physical damage. Always ensure the model you choose fits the intended installation area.
Is it A Wise Decision to Buy natural gas tankless water heater?
Absolutely. Investing in a natural gas tankless water heater is one of the smartest upgrades a homeowner can make for both long-term savings and daily convenience. While the initial purchase and installation cost is higher than that of a traditional storage tank heater, the benefits quickly outweigh the expense. The primary advantage is energy efficiency. A tankless unit only heats water on demand, eliminating the standby heat loss that occurs when a large tank of water is kept hot 24/7. This can lead to energy savings of 25-40%, resulting in a noticeable reduction in your monthly utility bills.
Beyond cost savings, the lifestyle improvement is significant. A properly sized tankless heater provides an endless supply of hot water, meaning you will never have to cut a shower short or schedule laundry around others’ needs. Their compact, wall-mounted design also frees up valuable floor space, often liberating an entire utility closet. Furthermore, tankless water heaters typically have a much longer lifespan than tank models—often 20 years or more compared to 10-15 years. When you consider the energy savings, endless hot water, space efficiency, and longevity, a natural gas tankless water heater is not just a purchase; it’s a wise, long-term investment in your home’s value and comfort.
What Is the Best Way to Choose natural gas tankless water heater?
Choosing the best natural gas tankless water heater involves a systematic approach to match a unit’s capabilities with your specific household needs. Follow these steps for a confident purchase.
1. Calculate Your Peak Hot Water Demand: First, determine your required Gallons Per Minute (GPM). List all the hot water fixtures in your home (showers, faucets, dishwasher) and their individual flow rates (usually found on the fixture or online). Add up the GPM for the fixtures you are likely to use simultaneously during peak times. This is your target GPM. It is always better to slightly oversize than to undersize.
2. Determine Your Required Temperature Rise: Next, find the temperature of your incoming groundwater. You can find this online for your specific region. Subtract this temperature from your desired hot water output temperature (typically 120°F). For example, if your groundwater is 50°F, you need a 70°F temperature rise (120 - 50 = 70). A heater’s GPM rating decreases as the required temperature rise increases, so check manufacturer charts to ensure your chosen model can meet your GPM needs at your required temperature rise.
3. Select an Installation Location (Indoor vs. Outdoor): Decide whether an indoor or outdoor unit is best for your home. Outdoor models save indoor space but are subject to weather. Indoor models are protected but require proper, often complex, venting to the outside. This decision will significantly narrow down your product options. For smaller applications, you may want to check out the best point of use tankless water heater.
4. Compare Key Features and Warranties: Once you have a list of models that meet your GPM and location needs, compare their features. Look for high UEF ratings for better efficiency, durable heat exchanger materials (stainless steel or high-grade copper), and user-friendly controls. Pay close attention to the warranty, especially the length of coverage for the heat exchanger, which is the most critical component.
5. Budget for Professional Installation: Never underestimate the importance and cost of professional installation. Improper installation of a gas appliance is extremely dangerous and will void the warranty. Get quotes from several licensed plumbers who have experience with tankless water heaters. Factor this cost into your total budget.
Common Mistakes to Avoid:
- Undersizing the Unit: Buying a heater with too low a GPM is the most common mistake and leads to lukewarm showers and frustration.
- Ignoring Venting Requirements: Indoor units have strict venting needs (often using specific stainless steel pipes). Failing to plan for this can lead to major installation headaches and safety hazards.
- Forgetting About Gas Line Size: High-BTU tankless heaters may require a larger diameter gas line than your old tank heater. This can be an unexpected and costly part of the installation.
FAQ
What is the best natural gas tankless water heater for beginners? For beginners, a model like the Rinnai V53DeN is an excellent choice. It comes from a highly reputable brand, offers straightforward operation, and provides enough hot water (5.3 GPM) for most small to medium-sized homes. Its outdoor design also simplifies venting requirements, making the installation process less complex. It is a reliable entry point into the world of tankless heating without being overwhelming.
How much should I spend on natural gas tankless water heater? You can expect to spend between $400 for a basic, lower-GPM model and up to $2,000 or more for a high-capacity, high-efficiency unit with smart features. A good mid-range price for a reliable heater for an average-sized family is typically between $800 and $1,300. Always remember to factor in the cost of professional installation, which can add several hundred dollars to the total investment.
What features are most important in natural gas tankless water heater? The three most important features are the flow rate (GPM), the BTU input (heating power), and the Uniform Energy Factor (UEF) for efficiency. After these, look for a durable heat exchanger (stainless steel is often preferred for longevity), a strong warranty (12+ years on the heat exchanger is great), and any safety certifications like CSA or UL listing for peace of mind.
How do I maintain my natural gas tankless water heater? The primary maintenance task is to descale the unit annually, especially in areas with hard water. This involves flushing the system with a vinegar solution to remove mineral buildup from the heat exchanger. Many modern units have built-in service valves and flush features that simplify this process. You should also have the unit inspected by a professional every few years to check for any issues.
Are expensive natural gas tankless water heater worth it? Often, yes. More expensive models typically offer higher flow rates (more GPM), better energy efficiency (condensing technology), more robust materials like stainless steel heat exchangers, longer warranties, and advanced features like Wi-Fi control or leak detection. If you have a large family or want the best long-term performance and reliability, investing in a premium model is usually worth the cost.
What brands make the best natural gas tankless water heater? Rinnai, Rheem, and Noritz are widely considered the top-tier brands in the tankless water heater market. They have decades of experience, a strong reputation for reliability, and excellent customer support. Brands like FOGATTI and MIZUDO are also gaining popularity for offering great value and innovative features. Sticking with a well-regarded brand generally ensures better quality and easier access to parts and service.
How long do natural gas tankless water heater typically last? A well-maintained natural gas tankless water heater can last 20 years or even longer. This is a significant advantage over traditional tank water heaters, which typically need to be replaced every 10-15 years. The longevity of a tankless unit is one of the key factors that helps offset its higher initial purchase price over the life of the appliance.
Can I find good natural gas tankless water heater on a budget? Yes, you can. Models like the ORBEK 4.3 GPM or MIZUDO 3.6 GPM offer reliable performance and important safety certifications at a very competitive price. While they may not have the high flow rates or advanced features of premium models, they are an excellent and efficient choice for apartments, condos, and smaller homes, providing endless hot water without breaking the bank.
Final Verdict
After extensive review and comparison, the Rinnai RX199iN Condensing Smart Sense Heater stands out as the best overall natural gas tankless water heater. Its incredible versatility for indoor or outdoor installation with either gas type, combined with a massive 11.1 GPM flow rate and top-tier energy efficiency, makes it a future-proof solution for any home, large or small.
For those on a tighter budget, the ORBEK 4.3 GPM Indoor Heater offers unbeatable value. It delivers reliable performance with excellent temperature stability and robust safety features, making it a smart and affordable upgrade for smaller homes and apartments.
If your priority is maximum output for a large, busy household, the Rheem RTGH Series 8.4 GPM Heater is the premium choice. Its powerful performance ensures you will never run out of hot water, even under the heaviest demand, and it’s backed by one of the best warranties in the industry.
Ultimately, choosing the right heater depends on your specific needs. Assess your home’s hot water demand, consider your budget, and use this guide to select the perfect model that will provide you with endless, efficient hot water for years to come.
