Best Condensing Tankless Water Heater in 2025: Tested and Reviewed

When it comes to upgrading your home’s water heating system, the condensing tankless water heater stands out as a top choice for efficiency, cost savings, and continuous hot water. These high-tech units are designed to maximize energy use, reduce waste, and provide you with hot water only when you need it. But with so many models on the market, choosing the best condensing tankless water heater can be a daunting task. In this guide, we’ve tested and reviewed the top best condensing tankless water heaters available, offering you a comprehensive look at their performance, features, and value for money.

List of the Best Condensing Tankless Water Heater:

Check out the detailed reviews below.

1. Rinnai RXP199iN Condensing Tankless Water Heater

The Rinnai RXP199iN Condensing Smart Sense Tankless Water Heater is a top-tier solution for on-demand hot water. This energy-efficient model delivers up to 11.1 GPM, making it ideal for large homes with multiple fixtures in use at the same time. With an impressive 98% energy efficiency factor (UEF), it saves on both water and power costs while maintaining high performance. Powered by either natural gas or propane, this versatile unit offers flexible installation options, whether indoors or outdoors, thanks to the innovative Versa Vent system.

Equipped with advanced features such as Smart-Circ Intelligent Recirculation, the RXP199iN learns your water usage patterns to optimize hot water availability. The Quick Flush function simplifies maintenance, ensuring long-lasting performance. Additionally, with Wi-Fi compatibility via the Control-R module, users can monitor and manage the water heater remotely for convenience. Compact and lightweight, this unit takes up minimal space, making it perfect for homes looking to save room while ensuring continuous hot water.

Key Features, Pros, and Cons

Key Features:

• Up to 11.1 GPM for simultaneous hot water across multiple fixtures.
• 98% energy efficiency (UEF), reducing water and energy costs.
• Smart-Circ technology for optimized water recirculation.
• Versa Vent system for both indoor and outdoor installation flexibility.
• Wi-Fi connectivity for remote control (Control-R module sold separately).

Pros:

• High energy efficiency for cost savings.
• Compact design fits in tight spaces.
• Advanced recirculation system ensures hot water availability.
• Quiet operation and quick heating.
• Flexible installation options for natural gas or propane.

Cons:

• Wi-Fi module sold separately.

2. Rheem RTGH-95DVELN-3 Condensing Tankless Water Heater

The Rheem RTGH-95DVELN-3 Super High Efficiency Condensing Indoor Tankless Natural Gas Water Heater offers continuous hot water for your entire home, even when multiple appliances are in use. Delivering up to 9.5 GPM, this water heater is ideal for large households with high hot water demand. Its energy-efficient design uses up to 34% less energy than a 50-gallon tank heater, making it a cost-effective option for long-term savings. The built-in EcoNet Wi-Fi technology allows users to control and monitor water usage remotely through their smartphones. Additionally, the LeakGuard Leak Detection and Prevention system ensures peace of mind by protecting your home from potential water damage.

With Hot Start Programming, the heater is always ready, preventing cold-water bursts. Its compact size and modern design make it easy to install in tight spaces, while the exclusive Water Saving Setting can save up to 1,100 gallons of water annually. Designed with an Overheat Film Wrap for added protection, the Rheem RTGH-95DVELN-3 is a reliable and efficient choice for homeowners looking for an advanced, space-saving solution.

Key Features, Pros, and Cons

Key Features:

• 9.5 GPM flow rate, suitable for large households.
• Built-in EcoNet Wi-Fi technology for remote control and monitoring.
• Energy-efficient design reduces energy consumption by 34%.
• LeakGuard Leak Detection prevents water damage.
• Compact size and modern design for easy installation in tight spaces.

Pros:

• Continuous hot water for multiple applications.
• Significant energy savings with a 34% reduction in consumption.
• Remote control through EcoNet app for convenience.
• Leak protection ensures peace of mind.
• Compact design saves valuable floor space.

Cons:

• Some users report noise during operation.

3. Rinnai CU160iN Condensing Tankless Water Heater

The Rinnai CU160iN Commercial Natural Gas Condensing Tankless Water Heater provides efficient and reliable hot water for commercial applications. With a powerful 9 GPM flow rate, this unit ensures optimal water pressure for businesses that require continuous hot water. Its space-saving design conserves energy, heating only when necessary, which significantly reduces utility costs. The inclusion of Circ-Logic technology allows for smart recirculation patterns that adapt to your business’s typical water usage, ensuring hot water is always available when needed. Additionally, Wi-Fi monitoring allows for remote control and monitoring, offering convenient and energy-saving capabilities.

Designed for indoor installation, this water heater comes with multiple venting options, providing flexibility in installation for various commercial environments. Backed by a robust warranty – 8 years for the heat exchanger, 5 years for parts, and 1 year for labor – the Rinnai CU160iN ensures long-lasting durability. Its high-quality materials, such as stainless steel and copper, add to its reliability, making it a smart investment for businesses. Whether it’s for a restaurant, educational institution, or multi-family dwelling, this tankless water heater provides a consistent, uninterrupted flow of hot water while reducing energy consumption.

Key Features, Pros, and Cons

Key Features:

• 9 GPM hot water flow rate, ideal for commercial settings.
• Circ-Logic technology for adaptive recirculation patterns.
• Wi-Fi monitoring for remote control and energy savings.
• Multiple venting options for flexible installation.
• Long-lasting performance with an 8-year heat exchanger warranty.

Pros:

• High-performance hot water flow rate.
• Energy-efficient design with on-demand heating.
• Wi-Fi monitoring for remote access and control.
• Flexible installation options for different setups.
• Durable materials ensure long-term reliability.

Cons:

• Larger size may not fit in all spaces..

How to Choose the Best Condensing Tankless Water Heater?

Choosing the right condensing tankless water heater is more than just a purchase – it’s an investment in comfort, efficiency, and long-term savings. With so many options available, making an informed decision can be overwhelming.

Why Choose a Condensing Tankless Water Heater?

Before we dive into the specifics, let’s first understand why a condensing tankless water heater might be the best option for you. Unlike traditional water heaters that store hot water in a tank, a tankless heater heats water on demand. Condensing models are highly efficient because they capture and reuse exhaust gases, maximizing energy use and reducing energy costs.

If you’re looking to upgrade your home’s water heating system or replace an old, inefficient heater, a condensing tankless water heater offers incredible benefits like energy savings, endless hot water, and a smaller carbon footprint. Now, let’s get into how to choose the right one.

1. Assess Your Hot Water Demand

The first step in choosing the best condensing tankless water heater is determining how much hot water you need. The heater’s capacity should align with your daily usage. Here’s how you can figure it out:

• Small households (1-2 people): If you live alone or with just one other person, a unit with a lower flow rate (around 3-4 GPM – Gallons Per Minute) should be enough.
• Medium-sized households (3-4 people): For families with average water usage, look for models with a flow rate of 5-6 GPM.
• Large households (5+ people): For bigger families or households with high water demand, such as multiple bathrooms or large appliances, go for units with a flow rate of 7 GPM or more.

Think about your daily habits too – if you often run multiple showers or appliances simultaneously, you’ll want to ensure your tankless heater can handle it all.

2. Fuel Type: Gas or Electric?

When it comes to condensing tankless water heaters, they typically come in two fuel options: gas (natural gas or propane) and electric. The choice depends on your available energy source and your home’s infrastructure.

• Gas-powered models are generally more powerful, able to provide hot water to multiple outlets at once. They’re also a great choice if you need higher flow rates.
• Electric models, on the other hand, are easier to install and are perfect for smaller homes or apartments. However, they may struggle to meet the hot water demands of larger households.

If you already have a gas line in your home, a gas-powered heater is often the way to go, as it offers a better performance-to-cost ratio.

3. Size and Installation Location: Compact, But Powerful

One of the key advantages of a condensing tankless water heater is its compact size. These units are typically much smaller than traditional tank heaters, which makes them perfect for tight spaces like closets or small utility rooms.

However, when deciding on the best model, take the space where you’ll be installing the unit into consideration. Ensure there’s enough room for proper ventilation, as gas-powered units will need adequate airflow. Also, think about accessibility for maintenance. Having easy access to the unit will save you time and hassle when you need service.

4. Efficiency and Energy Savings: Look for the ENERGY STAR Label

If you’re all about reducing your energy bills and environmental impact, efficiency should be at the top of your checklist. Condensing tankless water heaters are known for their superior efficiency, but you’ll want to verify the exact efficiency ratings.

Look for units with an ENERGY STAR label, which signifies that they meet strict energy efficiency guidelines. These units use less energy to heat water, ultimately saving you money in the long run. Some models boast an efficiency rating of up to 98%, which means you’re getting the most out of your energy use. It’s also a good idea to check for features like modulating burners, which adjust the water temperature in real-time, optimizing energy usage.

5. Brand Reputation and Warranty: Trustworthy Brands Make a Difference

As with any major appliance, the brand reputation plays a crucial role in your purchase. Look for brands that have a solid track record of customer satisfaction and reliable performance. Well-known brands like Rinnai, Navien, and Takagi offer high-quality condensing tankless water heaters that are designed to last.

Additionally, don’t overlook the warranty. A long warranty (often 10 years or more) is a good indicator that the manufacturer stands behind their product. Make sure the warranty covers not only parts but also labor, as this will save you from unexpected repair costs down the road.

6. Advanced Features: Convenience and Control at Your Fingertips

While the basic functionality of a condensing tankless water heater is to heat water, some models come with advanced features that can make your life even easier. Here are a few to look for:

• Wi-Fi Connectivity: Many newer models come with smart technology that allows you to control the water temperature remotely via an app. This is particularly useful if you want to monitor energy usage or adjust settings from anywhere in your home.
• Self-Cleaning: Over time, sediment and minerals can build up inside the heater. Some condensing tankless water heaters offer self-cleaning features that reduce maintenance.
• Built-in Recirculation: If you’re tired of waiting for hot water, look for models with recirculation technology, which ensures instant hot water delivery.

These features aren’t strictly necessary but can greatly enhance your experience if they fit your lifestyle.

7. Cost and Value for Money

While it’s tempting to opt for the cheapest model, keep in mind that you get what you pay for. Condensing tankless water heaters tend to be pricier than non-condensing units, but their efficiency can save you a significant amount on energy bills over time.

When assessing the cost, consider the long-term savings in energy and the potential for fewer repairs due to the higher quality of these units. The upfront price may be higher, but the return on investment (ROI) is well worth it.

Frequently Asked Questions (FAQ) About the Best Condensing Tankless Water Heaters

1. What is a condensing tankless water heater, and how does it work?

A condensing tankless water heater is a high-efficiency water heater that heats water on demand without the need for a storage tank. Unlike traditional tankless water heaters, condensing models use a heat exchanger to capture and recycle exhaust gases, increasing efficiency by using heat that would otherwise be wasted. This results in higher energy efficiency (up to 98%) and lower energy bills. The unit only heats water when you need it, which also means you’ll never run out of hot water.

2. What is the difference between a condensing and a non-condensing tankless water heater?

The primary difference lies in their efficiency and how they handle exhaust gases. Condensing tankless water heaters capture and reuse exhaust gases to increase efficiency, which allows them to achieve higher efficiency ratings (around 90%-98%). Non-condensing models, on the other hand, expel hot exhaust gases without utilizing the heat, making them less efficient. Condensing units are generally more energy-efficient, resulting in savings over time, while non-condensing units are typically cheaper upfront but can lead to higher operational costs.

3. What size condensing tankless water heater do I need for my home?

The size of the condensing tankless water heater you need depends on your household’s water usage. For small households with one or two people, a unit with a flow rate of 3-4 gallons per minute (GPM) should suffice. Medium-sized households may need a unit with a flow rate of 5-6 GPM, while larger households with higher water demands (e.g., multiple bathrooms) should consider units with a flow rate of 7 GPM or more. It’s essential to match the flow rate to the number of water outlets (sinks, showers, appliances) you expect to use simultaneously.

4. What is the average lifespan of a condensing tankless water heater?

The average lifespan of a condensing tankless water heater ranges between 15 and 20 years, which is significantly longer than that of traditional tank water heaters (typically 10-15 years). With proper maintenance, such as regular descaling and checking the unit for any potential issues, you can extend the lifespan of your condensing tankless water heater even further.

5. Do I need a venting system for a condensing tankless water heater?

Yes, a condensing tankless water heater requires a venting system to expel exhaust gases safely from the unit. However, unlike non-condensing models that require a vent system made of stainless steel, condensing models have a less corrosive exhaust, allowing them to use less expensive PVC or CPVC piping for venting. The venting system should be installed correctly to ensure safe operation and avoid damage to the unit.

6. Is it better to choose a gas-powered or electric condensing tankless water heater?

Choosing between gas and electric largely depends on your energy source and the size of your home. Gas-powered condensing tankless water heaters are typically more powerful and can handle higher flow rates, making them ideal for larger households or homes with multiple bathrooms and appliances. Electric units, while easier to install and requiring less maintenance, may struggle to meet the high demand for hot water in larger homes. Gas-powered units are usually the better option for large homes, while electric models are great for smaller households or apartments.

7. How much does a condensing tankless water heater cost?

The cost of a condensing tankless water heater can vary depending on the brand, model, and features, but generally, they range from $1,000 to $2,500. This price is higher than non-condensing tankless models, which typically cost between $500 and $1,500. However, the initial investment in a condensing model is often offset by long-term energy savings due to its higher efficiency. Additionally, installation costs (typically $500 to $1,500) should be factored into your budget, especially for gas models that require venting.

8. How energy-efficient is a condensing tankless water heater?

Condensing tankless water heaters are incredibly energy-efficient, often achieving efficiency ratings of 90%-98%. This is because they reuse heat from exhaust gases that would otherwise be wasted, resulting in minimal energy loss. In comparison, traditional tank water heaters only operate at around 60%-70% efficiency. By choosing a condensing unit, you can significantly reduce your energy consumption and lower your monthly utility bills.

9. How much can I save on energy bills with a condensing tankless water heater?

Energy savings vary depending on the size of your household, water usage, and the efficiency of your current water heating system. On average, homeowners can expect to save 20% to 30% on energy bills by switching to a condensing tankless water heater. These savings come from the unit’s high efficiency and the fact that it heats water on demand, reducing energy wastage from standing water in traditional tanks.

10. Are there any maintenance requirements for a condensing tankless water heater?

Yes, regular maintenance is essential to keep your condensing tankless water heater running efficiently. Key maintenance tasks include descaling the heat exchanger annually to remove mineral buildup, especially if you live in an area with hard water. You should also inspect the venting system to ensure it’s clear of debris and check the unit for any signs of wear or damage. It’s also recommended to schedule professional servicing every few years to maintain optimal performance.

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

While it’s possible to install a condensing tankless water heater yourself if you have plumbing and electrical skills, it’s generally recommended to hire a professional installer. Installing a tankless water heater involves handling gas or electricity, as well as venting requirements that need to comply with local codes. A licensed plumber or HVAC technician will ensure that your unit is installed safely and efficiently.

12. Will a condensing tankless water heater work in cold climates?

Yes, condensing tankless water heaters work well in cold climates, but there are a few considerations. Gas-powered models are typically more efficient in colder climates, as they can handle a larger temperature rise more easily. If you live in an area with freezing temperatures, you may also need to install a freeze protection system or ensure that the unit is installed indoors in a climate-controlled space to avoid damage from freezing.

13. What are the benefits of Wi-Fi connectivity in a condensing tankless water heater?

Many modern condensing tankless water heaters come with Wi-Fi connectivity, allowing you to monitor and control the unit remotely through an app on your smartphone. This feature can be incredibly convenient for adjusting temperature settings, scheduling hot water usage, or checking energy consumption. Additionally, some models allow for automatic diagnostics, helping you stay on top of any potential issues before they become major problems.

14. How do I know if a condensing tankless water heater is the best option for my home?

If you have a large family or high hot water demands, a condensing tankless water heater could be a great investment due to its superior efficiency and ability to meet high flow rates. Additionally, if you want to reduce your carbon footprint and save on energy costs over time, the long-term benefits of a condensing model may outweigh the higher initial price. Consider your home’s energy source, space for installation, and water heating needs to determine if this type of system is the best fit for you.

Conclusion

Selecting the best condensing tankless water heater for your home doesn’t have to be complicated. With the models we’ve reviewed in this blog, you now have a clear understanding of what to look for in terms of efficiency, performance, and features. Whether you prioritize energy savings, high flow rates, or advanced technology like Wi-Fi connectivity, there’s a perfect unit for every household.

Enjoyed this guide of best condensing tankless water heater? Then be sured to check out our other heaters reviews.

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