Best Non-Condensing Tankless Water Heater in 2025: Tested and Reviewed

If you’re tired of running out of hot water or paying high energy bills, it might be time to consider upgrading to a tankless water heater. But with so many options available, how do you know which one is right for you? In this review, we’ll dive into the best non-condensing tankless water heaters, tested and reviewed, to help you make an informed decision. Whether you’re looking for energy efficiency, ease of installation, or consistent hot water performance, we’ve got you covered.

List of the Best Non-Condensing Tankless Water Heater:

Check out the detailed reviews below.

1. Rheem RTG-70XLN-3 Non-Condensing Tankless Water Heater

The Rheem RTG-70XLN-3 is a high-efficiency outdoor tankless water heater designed to meet the needs of residential homes. With a maximum flow rate of 7.0 GPM, it delivers continuous hot water, making it ideal for homes with moderate to high water demands. The unit’s compact size, which is 19% smaller and 22% lighter than previous models, ensures easy installation and space-saving benefits. Weighing just 39.25 pounds, it is significantly more portable compared to traditional water heaters.

Energy efficiency is a standout feature of this unit. It uses up to 25% less energy than traditional tank systems and is 34% more efficient than a standard 50-gallon water tank. The unit also emits up to 65% less greenhouse gas NOx, making it an environmentally friendly choice. Additionally, its exclusive water-saving setting can reduce water waste by saving up to 1,100 gallons of water per year. Hot-start programming ensures that there is no cold water burst when turning on the faucet, offering a seamless and comfortable water heating experience.

Key Features, Pros, and Cons

Key Features:

1. 7.0 GPM flow rate for continuous hot water.
2. Energy-efficient design reduces energy consumption by 25%.
3. Water-saving feature saves up to 1,100 gallons per year.
4. Compact size saves 19% in space and 22% in weight compared to previous models.
5. Hot-start programming prevents cold-water bursts.

Pros:

1. High energy efficiency, reducing utility bills.
2. Compact and lightweight, easy to install in tight spaces.
3. Provides sufficient hot water for multiple applications simultaneously.
4. Saves significant water by reducing wasted flow.
5. Long lifespan, up to 2.5 times longer than traditional tank water heaters.

Cons:

1. Suitable only for moderate to large water demands (7.0 GPM may not be enough for very large households).

2. Rinnai RE180iP Non-Condensing Tankless Water Heater

The Rinnai RE180iP is a highly efficient non-condensing propane tankless water heater that provides on-demand hot water for residential use. With a maximum flow rate of up to 8.5 GPM, it is capable of servicing multiple fixtures simultaneously, making it ideal for homes with higher hot water demand. This unit’s 180,000 BTU input ensures it delivers a powerful and consistent flow of hot water, even during peak usage times. Designed for indoor installation, it is compact and space-saving, measuring just 14.05 inches wide and 27.24 inches tall—about the size of a small suitcase.

The RE180iP features Rinnai’s Smart-Circ️ Intelligent Recirculation technology, which learns your water usage patterns, ensuring hot water is always available while saving energy during low-use periods. It also boasts an LED display for easy operation and troubleshooting, and it is built to last, with a residential warranty covering the heat exchanger for 15 years. This unit is highly energy-efficient, saving you money on water and power costs by only heating water when needed.

Key Features, Pros, and Cons

Key Features:

1. Up to 8.5 GPM flow rate, ideal for multiple fixtures.
2. Smart-Circ️ Intelligent Recirculation for energy savings.
3. LED display for easy control and error codes.
4. Compact, suitcase-sized design for space savings.
5. 15-year warranty on the heat exchanger.

Pros:

1. Delivers continuous hot water even for multiple users.
2. Saves space with a compact design.
3. High energy efficiency reduces utility bills.
4. Smart recirculation system ensures hot water availability while minimizing energy use.
5. Long-lasting durability with a 15-year heat exchanger warranty.

Cons:

1. Professional installation is required, which may add to initial costs.

3. Rheem RTG-70DVLN-3 Non-Condensing Tankless Water Heater

The Rheem RTG-70DVLN-3 offers a high-efficiency solution for homeowners looking to provide continuous hot water with minimal energy consumption. With a maximum flow rate of 7.0 GPM, it can comfortably support multiple applications simultaneously, such as showers, dishwashers, and laundry. This model is designed to save energy, using up to 25% less energy than traditional water heaters and is 34% more efficient than a 50-gallon tank water heater.

The unit’s compact size, measuring just 13.5 inches in width and 24.2 inches in height, ensures it can be installed in tight spaces, saving valuable room in your home. Featuring Rheem’s Hot-Start programming, it ensures hot water is always ready, eliminating cold-water bursts during consecutive uses. Additionally, the RTG-70DVLN-3 includes a LeakGuard Leak Detection and Prevention system, which monitors for internal leaks, providing an added layer of protection for your home. The energy-efficient design reduces your monthly bills, and the water-saving feature helps save up to 1,100 gallons annually.

Key Features, Pros, and Cons

Key Features:

1. 7.0 GPM flow rate for multiple simultaneous uses.
2. Hot-start programming prevents cold water bursts.
3. LeakGuard Leak Detection protects against water damage.
4. Energy-efficient, reducing energy consumption by up to 25%.
5. Compact, space-saving design for easy installation.

Pros:

1. Provides continuous hot water without delay.
2. Saves energy and reduces water waste.
3. Easy to install in tight spaces.
4. Protects home from potential water leaks.
5. Long-lasting with reduced environmental impact.

Cons:

1. Noise level may be a concern for some users.

4. Rinnai RE140iN Non-Condensing Tankless Water Heater

The Rinnai RE140iN is a highly efficient non-condensing natural gas tankless water heater designed for residential indoor installation. With a maximum flow rate of 5.3 GPM, it delivers reliable hot water to multiple fixtures at once, making it perfect for smaller to medium-sized households. Its 140,000 BTU input ensures powerful performance, meeting your daily hot water needs while reducing energy consumption. The unit’s compact design, about the size of a small suitcase, allows for easy installation in tight spaces, maximizing your home’s available real estate.

This model features a smart and durable design, with an LED display that offers easy access to error codes and system status. It is also equipped with a 15-year warranty on the heat exchanger, providing peace of mind for long-term use. While designed for efficiency, it also incorporates user-friendly features such as a WiFi control option (via the Rinnai Controlr, sold separately) for enhanced convenience. The RE140iN is ideal for homes in warmer climates, where it performs reliably and efficiently.

Key Features, Pros, and Cons

Key Features:

1. Provides up to 5.3 GPM for simultaneous hot water use.
2. 140,000 BTU ensures reliable and consistent hot water.
3. Compact, suitcase-sized design for easy installation.
4. LED display for easy monitoring and troubleshooting.
5. 15-year heat exchanger warranty for long-term durability.

Pros:

1. Efficient hot water delivery for multiple fixtures.
2. Saves space with compact design.
3. User-friendly with WiFi control option.
4. Long-lasting with a strong warranty.
5. Reliable and efficient in warm climates.

Cons:

1. Professional installation required, adding to the cost.

How to Choose the Best Non-Condensing Tankless Water Heater?

Are you ready to switch to a tankless water heater but don’t know where to start? Whether you’re replacing an old model or making the leap to energy-efficient living, choosing the right non-condensing tankless water heater can make all the difference.

What is a Non-Condensing Tankless Water Heater?

Before we get into the details, it’s important to understand exactly what a non-condensing tankless water heater is. Unlike their condensing counterparts, which capture and reuse heat from exhaust gases, non-condensing models vent these gases outside without additional heat recovery. This typically results in a slightly lower efficiency but also a more straightforward design that’s easier to install and maintain.

How to Know if a Non-Condensing Model is Right for You?

Choosing between a non-condensing and condensing tankless water heater depends on several factors, including your home’s size, energy consumption needs, and budget. Non-condensing units are ideal for homes where the water heating demand is not extremely high, or for users who want a simpler and less expensive system. If you’re looking for a more affordable solution and don’t need to maximize efficiency to the same extent as a condensing unit, a non-condensing model is the way to go.

Key Features to Look For When Choosing a Non-Condensing Tankless Water Heater

When selecting a non-condensing tankless water heater, you should focus on several key specifications. These factors will help you determine which model suits your needs best.

1. Flow Rate (Gallons per Minute – GPM)

The flow rate indicates how much hot water the heater can deliver per minute. A higher GPM means more hot water for simultaneous uses, such as running multiple showers or using appliances at the same time. Consider your household size and average water usage. For example, a 2-3 GPM model is typically sufficient for small households, while larger families may require a unit with a GPM of 5 or more.

2. Temperature Rise Capacity

The temperature rise is the difference between the incoming water temperature and the desired output temperature. A tankless heater’s ability to achieve a higher temperature rise is essential if you live in colder climates, where incoming water temperature is lower. Make sure to check this specification to avoid underperformance, especially during winter.

3. Energy Efficiency

Even though non-condensing models are generally less efficient than condensing models, it’s still important to check the energy efficiency ratings. Many non-condensing units offer a good balance of performance and energy savings, typically with an Energy Factor (EF) ranging from 0.8 to 0.9. A higher EF means greater efficiency, which translates into lower energy bills.

4. Dimensions and Installation Flexibility

Non-condensing tankless water heaters are usually compact, making them ideal for tight spaces like small utility rooms or closets. However, it’s still crucial to consider the available installation space. Ensure the unit fits within your chosen area, and remember that venting for non-condensing units is typically a bit more straightforward, often requiring only a standard vent pipe.

5. Warranty and Durability

A good warranty can provide peace of mind and ensure you won’t be left footing the bill for unexpected repairs. Look for models with at least a 5-10 year warranty on the heat exchanger and a 1-3 year warranty on other components. Durability is a key factor for long-term satisfaction, so don’t hesitate to go for a slightly pricier option if it comes with better reliability and protection.

Frequently Asked Questions About the Best Non-Condensing Tankless Water Heaters

1. What is a non-condensing tankless water heater?

A non-condensing tankless water heater is a type of water heater that heats water on demand without storing it in a tank. Unlike condensing models, which capture and reuse exhaust heat, non-condensing units vent the exhaust gases directly outside. These heaters tend to be simpler in design and often cost less to install and maintain, but they are less efficient compared to condensing models.

2. How does a non-condensing tankless water heater work?

A non-condensing tankless water heater works by heating water as it passes through the unit via a high-efficiency heat exchanger. When you turn on the hot water tap, cold water flows into the heater, where it is quickly heated by a gas burner or electrical element. The exhaust gases created during this process are vented directly to the outside through a standard vent pipe.

3. What are the advantages of using a non-condensing tankless water heater?

Non-condensing tankless water heaters offer several advantages:

• Lower upfront cost: They are generally less expensive to purchase and install compared to condensing units.
• Simplicity: Their design is simpler, making installation and maintenance easier and less costly.
• Efficient for moderate use: Non-condensing models can provide reliable hot water for smaller households or areas with less intense water usage.
• Compact size: Like all tankless heaters, non-condensing models are compact and take up less space compared to traditional tank water heaters.

4. Are non-condensing tankless water heaters energy efficient?

Non-condensing tankless water heaters are not as energy-efficient as their condensing counterparts. They typically have an energy factor (EF) rating between 0.80 and 0.90, meaning they lose some heat through the venting process. However, they still offer significant energy savings compared to traditional tank heaters, as they only heat water when needed, avoiding standby heat loss.

5. How do I choose the best non-condensing tankless water heater for my home?

When selecting the best non-condensing tankless water heater, consider these factors:

• Flow Rate (GPM): Choose a model with a flow rate that matches your water usage needs. For example, if you have a small household, a unit with a flow rate of 3-4 GPM may suffice, while larger homes may need 5-6 GPM.
• Temperature Rise: Ensure the heater can handle the temperature rise needed for your region. If you live in a cold climate with lower incoming water temperatures, you’ll need a unit with a higher temperature rise capacity.
• Size and Installation Space: Check the dimensions to ensure the unit will fit in your available space, and consider the venting requirements.
• Warranty and Durability: Look for a unit with a solid warranty (typically 5-10 years on the heat exchanger) to ensure long-term reliability.

6. Can a non-condensing tankless water heater be installed outdoors?

Yes, many non-condensing tankless water heaters are designed for outdoor installation. These units are typically built to withstand weather elements and can be mounted on exterior walls. However, you should check the manufacturer’s specifications to ensure the model you choose is rated for outdoor use, as some units are only suitable for indoor installation.

7. How much does it cost to install a non-condensing tankless water heater?

The cost of installing a non-condensing tankless water heater can vary depending on the brand, model, and complexity of the installation. On average, the cost for installation ranges between $1,000 and $2,500. Factors that influence the price include the need for venting modifications, electrical or gas line upgrades, and labor costs in your area.

8. How long do non-condensing tankless water heaters last?

Non-condensing tankless water heaters typically last around 15-20 years with proper maintenance. Regular cleaning and periodic servicing of the unit can help extend its lifespan. However, the longevity may vary based on factors such as water quality, frequency of use, and proper installation.

9. Are non-condensing tankless water heaters suitable for large families?

Non-condensing tankless water heaters can work for larger families, but you may need to choose a model with a higher flow rate (around 5-6 GPM or more) to ensure enough hot water is available for multiple taps and appliances running simultaneously. If your household demands a lot of hot water at once, a larger unit may be necessary to avoid running out of hot water.

10. What maintenance is required for a non-condensing tankless water heater?

Non-condensing tankless water heaters require basic maintenance to keep them running efficiently. Key maintenance tasks include:

• Descaling: If you live in an area with hard water, you may need to descale the unit once a year to prevent mineral buildup.
• Cleaning the air filter: Regularly clean the air filter to ensure proper airflow.
• Inspecting the venting system: Check the venting system for blockages or debris to ensure safe exhaust gas venting.

11. Can I install a non-condensing tankless water heater myself?

While some DIY enthusiasts may be able to install a non-condensing tankless water heater, it’s generally recommended to hire a licensed professional for installation. Tankless water heaters require proper venting, electrical or gas hookups, and safety checks that may require a professional’s expertise to ensure the unit operates efficiently and safely.

Conclusion

Choosing the best non-condensing tankless water heater ultimately depends on your home’s specific needs and your personal preferences. After testing and reviewing the top models, it’s clear that there are several excellent options available, each offering a unique set of features suited to different households. From flow rate and temperature rise to installation ease and warranty coverage, we hope this review helps you make the right choice.

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