By PickSmartly Editorial Team
· Updated Aug 4, 2026
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When it comes to reliable domestic water heating, Noritz has established itself as a heavyweight in the industry, particularly through its advanced tankless technology. Unlike traditional tank heaters that keep a large reservoir of water hot 24/7, Noritz natural gas heaters focus on on-demand heating, providing a continuous stream of hot water only when a fixture is activated. This efficiency makes them a premier choice for homeowners looking to reduce energy waste and reclaim floor space. However, choosing the right unit is not as simple as picking the largest model available. It requires a nuanced understanding of your home's specific plumbing demands and gas line capacity.
Editor's Choice
Our Top Picks for Noritz Natural Gas Heaters
The three standouts our editors recommend first — ranked by performance, value, and real-world reviews.
On demand a continuous and unlimited supply of hot water
Sleek design saves space and no venting required, It also features two different temperature memory presets, making it easy to adjust for personalized needs.
Requires hard-wired 240 or 208-volt electric service, with a maximum draw of 28,800 watts at 240 volts or 21,600 watts at 208 volts
Requires 3 separate dedicated 40 amp breakers with 8 gauge copper wiring, and a minimum of 200 amp total service to the residence
Why settle for a lukewarm shower when you can have an endless stream of hot water on demand? The Stiebel Eltron Tempra 29 Plus is a game-changer for homeowners looking to reclaim their utility closet space without sacrificing performance. Because it is a tankless system, you can ditch the bulky, space-hogging traditional tanks in favor of this sleek, white unit that requires no venting. I love the convenience of the two temperature memory presets, which let you jump between personalized settings without fiddling with dials every single time. Just keep in mind that this is a heavy-duty installation. You will need a 200-amp service and three dedicated 40-amp breakers to handle the significant electrical draw. It is a premium, high-efficiency solution for modern homes.
Large households facing the dreaded 'cold shower surprise' need the Noritz NRC66DVNG to reclaim their morning routines. This condensing unit delivers an endless supply of hot water at a 6.6 GPM flow rate, effectively eliminating the limitations of traditional storage tanks. What sets this model apart for installers is the ability to vent using standard Schedule 40 PVC pipe, which simplifies the setup process significantly. It operates with high efficiency and low Nox emissions, making it a smart choice for environmentally conscious homeowners. The inclusion of a remote thermostat and a six-foot power cord means you have the essential control components right out of the box, making it a comprehensive solution for modern indoor water heating needs.
Stepping into a steaming shower after a long day becomes a seamless experience rather than a race against a cooling tank. The Noritz NR50ODNG delivers a steady 5.0 GPM flow that eliminates the dreaded 'cold water sandwich' common with traditional units. Designed specifically for outdoor installation, this 120,000 Btuh powerhouse provides endless hot water without taking up precious indoor square footage. I was particularly impressed by the high-efficiency design, which minimizes waste while maintaining a low Nox profile for a cleaner burn. At a price point, it offers a professional-grade solution for homeowners looking to upgrade their utility efficiency and ensure their hot water supply never runs dry.
Why should you ever have to settle for a lukewarm shower again? The Noritz NR66ODNG solves the age-old problem of running out of hot water by providing an endless supply through its high-efficiency design. We found that its 140,000 Btuh capacity and 6.6 GPM flow rate make it a powerhouse for outdoor installations, whether you are upgrading a patio setup or a secondary utility space. It operates with a low NOx profile, which is a significant win for those mindful of their environmental footprint. With a UEF of 0.81, this unit balances performance with energy efficiency, ensuring you aren't wasting fuel just to keep the water warm. It is a robust, reliable solution for anyone needing consistent heat on demand.
Most households struggle with the inevitable lukewarm shower, but the Noritz NRC66ODNG eliminates that compromise entirely by providing a steady stream of endless hot water. I found that this unit is a game-changer for anyone looking to upgrade their home efficiency without sacrificing performance. Because it is a condensing model, it hits very high efficiency levels that make a noticeable difference in energy usage. The compact, space-saving design is a massive plus if you are installing this in a tight outdoor area, and the low NOx output ensures you are being mindful of environmental impact. It is a robust, reliable solution for anyone tired of waiting for a tank to reheat.
Homeowners looking to upgrade their outdoor living space or expand their hot water capacity without the headache of complex venting need to look at this Noritz unit. It delivers a massive 199,000 BTU output, which is impressive for a system designed specifically for outdoor installation. I found the .05 GPM activation flow rate particularly useful because it ensures the heater responds almost instantly to even the slightest water usage. With 84% thermal efficiency and a built-in self-diagnostic computer, you get a high-performance machine that handles its own troubleshooting. It is a robust, high-flow solution that eliminates the need for indoor space while providing a steady 7.5 GPM stream whenever you need it.
A sudden rush of cold water during a morning shower is a nightmare you can finally avoid with this heavy-duty Noritz unit. This 380,000 BTU powerhouse is designed for high-demand households, delivering an impressive 13.2 GPM to ensure multiple taps can run simultaneously without a dip in temperature. I was particularly struck by the ultra-low .07 GPM activation flow rate, which means even a trickle of water triggers the heating process instantly. The build quality feels substantial thanks to the HRS35 copper heat exchanger casing, which features a specialized protective coating for added longevity. While you will need to factor in the cost of 4" category III stainless steel venting, the 80% thermal efficiency makes it a reliable cornerstone for any indoor or outdoor installation.
The Noritz NRC71ODNG delivers relentless hot water performance through its high-efficiency condensing technology. This outdoor unit is a powerhouse for anyone tired of running out of hot water mid-shower, offering a steady 7.1 GPM flow rate. I was particularly impressed by the intelligent safety design, which includes a thermal fuse automatic overheat protection system to keep things running smoothly. Because it uses direct ignition rather than a standby pilot light, you aren't wasting energy just waiting for a tap to turn. It’s a substantial piece of plumbing hardware at roughly 22 kilograms, but the build quality feels substantial enough to handle outdoor elements. For a permanent home improvement upgrade, this natural gas system provides a reliable, modern solution to traditional tank limitations.
Smart Design: Improved design of tankless hot water heater only heats when necessary to conserve energy. Speeds installation and enhances serviceability with a cleaner internal layout. LED screen provides service reminders and error codes
Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: This non-condensing indoor tankless hot water heater from Rinnai is only the size of a small suitcase, but provides up to 7.6 GPM (6 fixtures at once)
Smart, Durable Design: Water heater includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively. See Controlr module for WiFi control (not included). See REP199iN for model with included pump
Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your tankless water heater. We do not recommend installing a water heater without a technician
Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater for your home. Check our Ground Water Temperature Map to see if this heater is optimal for your region
Large families struggling with lukewarm showers need to ditch their bulky tanks for the Rinnai RE199iN immediately. This unit is a powerhouse disguised as a small suitcase, delivering up to 7.6 GPM to support six fixtures simultaneously without breaking a sweat. I love how the smart design focuses energy only when water is actually running, which is a massive win for efficiency. The internal layout is much cleaner than older models, making it easier for technicians to service, and the built-in LED screen is a lifesaver for quick error code checks. While you will definitely want to hire a professional for the installation, the peace of mind provided by the long-term heat exchanger guarantee makes this a rock-solid investment for any modern home.
Homeowners looking to slash their energy bills while upgrading to a high-performance heating system need the Noritz NRC1111-DVNG immediately. This unit is a powerhouse of efficiency, utilizing advanced condensing technology to reach an impressive 93 percent efficiency level. What really sets it apart from standard models is the exclusive dual flame burner, which works alongside a fully modulating system to virtually eliminate those annoying temperature fluctuations during a shower. It is also incredibly versatile. The combi-system setup allows for an open loop functionality that handles both potable water and space heating. While the default safety lockout caps the temperature at 120 degrees F for peace of mind, it remains a top-tier choice for anyone wanting sophisticated, reliable warmth.
The Noritz NRC111-DV delivers an incredible 93% efficiency rating that fundamentally changes how you think about home energy consumption. By utilizing a condensing design that dramatically reduces carbon dioxide output, this unit is a powerhouse for eco-conscious homeowners who refuse to sacrifice performance. I was particularly impressed by the massive 199,900 BTU output paired with a remarkably low .05 GPM activation flow rate, meaning you won't deal with those annoying cold water stutters when someone turns on a tap. The build quality feels premium thanks to the hybrid stainless steel and copper heat exchangers, and the onboard self-diagnostic computer takes the guesswork out of maintenance. It is a robust, high-capacity solution for anyone needing a steady 8.4 GPM flow without the footprint of a traditional tank.
Most homeowners assume that upgrading to a high-capacity water heater means dealing with complex venting installations, but this Noritz outdoor unit completely ignores that headache. By moving the system outside, you bypass the need for venting entirely, which simplifies your home improvement project significantly. I was particularly impressed by the build quality. The heat exchanger is commercial-grade with copper that is 25% thicker than what you typically find in competing residential models. With a massive flow rate of 11.1 GPM, it handles multiple simultaneous showers without a dip in temperature. It even comes ready to go with a remote thermostat and a six-foot power cord, and if your household grows, you can easily link two units together using the Quick Connect Cord.
A busy hotel kitchen or a high-capacity fitness center demands hot water that never quits, and the Noritz NCC300ODNG is engineered specifically for those high-pressure environments. I was particularly impressed by the sheer volume this unit handles, delivering flow rates up to 13.2 GPM without breaking a sweat. Because it utilizes commercial-grade heat exchangers, it is built to endure the heavy-duty cycles that would destroy a standard residential unit. The scalability is where this system truly shines. You can link two units using the QC-2 Quick Connect Cord or even scale up to 24 units with the right controller for massive industrial applications. Plus, having Wi-Fi capability means you can monitor your system's performance remotely, making it a smart, reliable cornerstone for any commercial facility.
Homeowners stuck with an aging, bulky tank should stop looking elsewhere because the Noritz EZTR40 is the ultimate shortcut to modern efficiency. What sets this unit apart is the sheer speed of the transition. You can actually swap out your old tank-style system in roughly the same amount of time it takes for a standard replacement. The included N-FlexKit is a total game-changer for retrofitting, as it lets you install the unit directly inside your existing venting. With a flow rate reaching up to 6.6 GPM and a high energy factor of 0.91, you get consistent hot water without the massive footprint. It is a sophisticated upgrade that prioritizes ease of installation without sacrificing the high-performance gas power you need.
A Guide to Selecting the Best Noritz Natural Gas Heaters
Understanding Flow Rate and Capacity
The most critical metric in selecting a Noritz natural gas heater is the flow rate, typically measured in gallons per minute (GPM). This determines how many fixtures you can run simultaneously without experiencing a sudden drop in water temperature. If you live in a single-person household, a lower GPM unit might suffice. However, for a family where one person is showering while another is running the dishwasher, you will need a high-capacity unit. When calculating your needs, don't just look at the peak usage. Consider the 'simultaneous demand' of your most active times of day. A unit that is too small will result in lukewarm showers, while one that is excessively large may lead to unnecessary upfront costs and oversized venting requirements.
Temperature Rise and Climate Considerations
A common mistake is focusing solely on flow rate while ignoring 'temperature rise.' This is the difference between the temperature of the incoming cold water and your desired output temperature. In colder climates, the groundwater entering your home in winter is significantly chillier than in the summer. A heater that works perfectly in July might struggle in January if it doesn't have the BTU (British Thermal Unit) capacity to bridge that larger temperature gap. When shopping, check the unit's specifications for its ability to handle high temperature rises. If you reside in a northern region, prioritize models with higher BTU ratings to ensure consistent performance during freezing months.
Condensing vs. Non-Condensing Technology
Noritz offers two primary paths regarding efficiency: condensing and non-condensing models. Condensing heaters are the gold standard for energy efficiency. They are designed to capture heat from the exhaust gases that would otherwise be lost up the vent, recycling it back into the heating process. While these units have a higher initial purchase price, they offer significantly higher thermal efficiency and can lead to substantial long-term savings on your natural gas bill. Non-condensing models are generally more budget-friendly upfront and easier to vent, but they lose more energy through the exhaust. Your decision should be based on your long-term budget and your commitment to eco-friendly living.
Installation Requirements and Venting
Natural gas heaters require specific infrastructure that cannot be overlooked. Because these units burn gas to create heat, they require proper ventilation to exhaust combustion byproducts safely. Condensing models often require specialized PVC venting, which can be easier to install in certain configurations, whereas non-condensing models might require metal venting. Additionally, you must ensure your existing natural gas line has sufficient diameter and pressure to feed the heater. A high-BTU unit on an undersized gas line will lead to frequent error codes and inconsistent heating. It is highly recommended to consult with a professional to verify that your home's gas supply and venting paths are compatible with the specific Noritz model you select.
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Quick answers about Noritz Natural Gas Heaters before you buy.
Noritz tankless heaters provide endless hot water by heating it on demand, saving space and energy, whereas tank heaters store a set volume of water that can run out during heavy use.
While Noritz is famous for water heaters, they also produce high-efficiency gas-fired space heaters designed specifically for supplemental or primary indoor heating.
The BTU rating should be based on your square footage and local climate. Larger spaces or colder regions require higher BTU outputs to maintain consistent temperatures.
Yes, most Noritz gas models utilize condensing technology, which captures heat from exhaust gases to achieve much higher thermal efficiency ratings than standard models.
Installation requirements vary by model. High-efficiency condensing units often use specialized PVC venting, while standard models may require traditional metal flue venting.
Some specific models are designed for outdoor installation, but you must verify the specific unit's rating to ensure it is weather-resistant and meets local building codes.
With regular maintenance and proper sizing, a high-quality Noritz gas heater typically lasts between 10 to 15 years.
Yes, because these are natural gas models, they require a dedicated gas supply line and must be professionally installed to ensure safety and code compliance.
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Our Analysis of Noritz Natural Gas Heaters
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