Best Rated Natural Gas Tankless Water Heaters

Imagine hosting a family gathering where hot water runs out just as you’re getting ready for the big dinner. Or picture your morning routine disrupted by the sudden shock of cold water mid-shower. These scenarios are all too common with traditional water heaters, leaving many homeowners frustrated. Fortunately, the solution lies in natural gas tankless water heaters, which provide instant hot water on demand, eliminating those unexpected cold moments.

Choosing the right tankless water heater involves considering various factors like flow rate, efficiency, and safety features. The best-rated models not only deliver hot water reliably but also operate efficiently, saving you money on energy bills. Additionally, their compact designs free up valuable space in your home, making them ideal for modern living.

In this roundup, we’ve reviewed five of the best natural gas tankless water heaters available today. From high-capacity units perfect for larger families to compact models that fit snugly in smaller spaces, there’s something for everyone. Let’s dive into the details to find the right fit for your needs.

Here’s a quick comparison of key specifications:

Features	Rheem RTG 7.0 GPM	ThermoMate CZ422NG	APUS Tankless Heater	Ranein Tankless Heater	Rheem RTG 8.4 GPM
Max Flow Rate	7.0 GPM	5 GPM	4.42 GPM	8.5 GPM	8.4 GPM
BTU Output	160,000 BTU	113,000 BTU	95,000 BTU	190,000 BTU	180,000 BTU
Energy Factor	0.82 UEF	0.81 UEF	0.81 UEF	Not specified	0.82 UEF
Installation Type	Indoor	Indoor	Indoor	Indoor	Outdoor
Best Use	Large Families	Medium Households	Small Homes	Large Families	Large Families

Rheem RTG Series 7.0 GPM…

The Rheem RTG Series 7.0 GPM is an excellent choice for larger households needing consistent hot water. With its capacity to deliver 7.0 gallons per minute, this unit is ideal for homes with multiple bathrooms or simultaneous water needs.

What sets the Rheem RTG apart is its impressive BTU output of 160,000, ensuring you won’t run out of hot water during peak times. Its energy-efficient design saves up to 34% on energy costs compared to traditional tank heaters, making it a financially wise choice. The unit’s compact wall-mounted design is another plus, freeing up valuable floor space.

However, it’s essential to note that this model requires indoor installation, which can limit placement options. Additionally, while the digital temperature control is precise, some users may find it takes a bit of getting used to.

• Max Flow Rate: 7.0 GPM
• BTU Output: 160,000 BTU
• Energy Factor: 0.82 UEF
• Indoor installation required
• Digital temperature control

Best for: Large families needing consistent hot water for multiple outlets.

ThermoMate CZ422NG, Natur…

The ThermoMate CZ422NG is designed for medium-sized households, providing up to 5 GPM of hot water. This unit is perfect for families that want to enjoy simultaneous showers without cold interruptions.

This model excels in its thermal efficiency, achieving up to 98% with a UEF of 0.81. The smart control chip adjusts the heating output 20,000 times per second, ensuring a stable water temperature. Additionally, its compact design makes it easy to install and saves space in your home.

On the downside, while it offers solid performance, the maximum flow rate may not meet the needs of larger families during peak water usage times. Also, the unit’s features, while advanced, require some familiarity for optimal use.

• Max Flow Rate: 5 GPM
• BTU Output: 113,000 BTU
• Energy Factor: 0.81 UEF
• Compact design for easy installation
• Smart temperature control

Best for: Medium households that need efficient, consistent hot water.

APUS Natural Gas Tankless…

The APUS Natural Gas Tankless Water Heater is a powerful unit that provides 4.42 GPM, making it a versatile choice for smaller homes. It meets the demands of two showers and a sink running simultaneously without sacrificing water temperature.

This model stands out with its innovative low-flow start technology, ensuring you have hot water even at lower flow rates. It also features high-precision sensors, which maintain a steady temperature within ±1°F. Its compact size and quiet operation make it suitable for various setups without disturbing your household.

However, its lower BTU output of 95,000 might not suffice for larger families or homes with high hot water demands. Users should also consider its indoor-only installation limitations, which could restrict placement options.

• Max Flow Rate: 4.42 GPM
• BTU Output: 95,000 BTU
• Energy Factor: 0.81 UEF
• Low-flow start technology
• Quiet operation

Best for: Smaller homes needing reliable hot water for basic needs.

Ranein Natural Gas Tankle…

The Ranein Natural Gas Tankless Water Heater boasts an impressive flow rate of 8.5 GPM, ideal for larger households with multiple outlets. Its 190,000 BTU capacity ensures that everyone can enjoy hot water simultaneously without delay.

This model features a fan placed underneath to enhance safety and efficiency. It automatically adjusts its operation based on the external environment, promoting optimal combustion. Users appreciate its quick installation process and compact design, which fits well into tight spaces.

Although the high capacity is a significant advantage, this unit might be overkill for smaller households. Additionally, prospective buyers should be aware of its indoor installation requirements, which could limit flexibility.

• Max Flow Rate: 8.5 GPM
• BTU Output: 190,000 BTU
• Compact size for easy installation
• Safety-enhancing fan system
• Suitable for large families

Best for: Large families needing abundant hot water for multiple outlets.

Rheem RTG Series 8.4 GPM…

The Rheem RTG Series 8.4 GPM is another exceptional option for large families, delivering hot water on demand with a flow rate of 8.4 GPM. This outdoor installation model is perfect for homes with multiple bathrooms or high hot water needs.

With a BTU output of 180,000, this unit efficiently supplies hot water even during peak usage. The energy factor of 0.82 means it saves on energy costs, making it a wise investment in the long run. The digital temperature control allows precise adjustments, ensuring you get the perfect temperature every time.

Keep in mind that this model requires professional installation, which might add to the overall cost. Additionally, being an outdoor unit, it may not be suitable for homes without adequate space outside.

• Max Flow Rate: 8.4 GPM
• BTU Output: 180,000 BTU
• Energy Factor: 0.82 UEF
• Outdoor installation required
• Digital temperature control

Best for: Large families with high hot water demands.

How We Chose These Products

Our selection of the best natural gas tankless water heaters was based on thorough research and user feedback. We evaluated each model’s flow rate, BTU output, energy efficiency, and safety features. Customer reviews provided insights into real-world performance, helping us identify reliable products that meet various household needs.

We also considered installation requirements and overall design. Space-saving models that offer easy installation options ranked higher in our evaluations, as these factors are crucial for homeowners looking to upgrade their hot water solutions.

Buying Guide: What Really Matters

When selecting a natural gas tankless water heater, prioritize flow rate and BTU output to ensure it meets your household’s hot water needs. A higher flow rate is essential for larger families or homes with multiple bathrooms. Energy efficiency ratings, like the Uniform Energy Factor (UEF), help gauge long-term savings on utility bills.

Safety features are equally important. Look for models with built-in protections against freeze, flame failure, and overheating. Installation type—indoor or outdoor—also impacts your choice, as it affects where the unit can be placed and how it connects to existing plumbing and gas lines.

Our Top Recommendation

For households with high hot water demands, the Rheem RTG Series 8.4 GPM is our top pick. It provides impressive capacity, energy savings, and advanced temperature control. If your needs are more moderate, the ThermoMate CZ422NG offers great efficiency and performance for medium-sized families.

Frequently Asked Questions

1. Can I install a tankless water heater myself?
While some homeowners may attempt a DIY installation, professional installation is recommended for gas models due to safety concerns and local codes.

2. How long do tankless water heaters last?
Typically, tankless water heaters can last over 20 years with proper maintenance, significantly longer than traditional tank models.

3. What maintenance does a tankless water heater require?
Regular descaling and occasional inspection of gas connections and filters are essential to keep your tankless heater running efficiently.

4. Are tankless water heaters worth the investment?
Yes, they offer substantial savings on energy bills and provide endless hot water, making them a worthwhile investment for many homeowners.