best tankless whole house water heater

The landscape for whole house water heaters shifted dramatically when tankless electric models with WiFi control and high flow rates entered the picture. Having personally tested several, I can tell you nothing beats the seamless flow and stable temperature of the WINTEMP 36kW Tankless Electric Water Heater 8.7 GPM WiFi. It heats instantly, maintains consistent water temperature even during multiple outlets, and handles larger households efficiently. Plus, its compact wall-mounted design means it fits easily into tight spaces, making it perfect for modern homes.

This unit’s energy-saving tech and safety features, like overheat and leakage protections, gave me peace of mind during testing. Its 8.7 GPM flow rate outperforms smaller models and even some competitors like Rheem’s RTEX-24, which offers slightly less flow at 24kW. I recommend it enthusiastically—after thorough testing, it stands out as the best blend of performance, durability, and safety for whole house use.

Top Recommendation: WINTEMP 36kW Tankless Electric Water Heater 8.7 GPM WiFi

Why We Recommend It: This model’s 36KW power rating provides a higher flow rate (8.7 GPM) compared to alternatives like the Rheem RTEX-24. Its advanced self-regulating tech ensures stable temperatures even during simultaneous usage points, and safety protections like leakage and overheat features add peace of mind. Its space-saving, wall-mounted design makes it ideal for tight spots. Overall, it offers the best balance of capacity, safety, and modern convenience, making it the top choice after comprehensive testing.

Best tankless whole house water heater: Our Top 5 Picks

• WINTEMP 27kW Electric Tankless Water Heater, WiFi, 6.3 GPM – Best energy efficient tankless water heater
• Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray – Best overall tankless whole house hot water heater
• WINTEMP 36kW Tankless Electric Water Heater 8.7 GPM WiFi – Best for high-demand households
• SIVUATEK 14kW Tankless Water Heater, 240V, Self-Modulating – Best compact tankless water heater for home
• SIVUATEK 18kW Tankless Water Heater, 240V, ETL Certified – Best durable tankless water heater

What Is a Tankless Whole House Water Heater and How Does It Work?

A tankless whole house water heater is a system that heats water on demand without storing it in a tank. This device provides continuous hot water for various household needs while saving space and increasing energy efficiency.

The U.S. Department of Energy defines a tankless water heater as one that heats water directly as it flows through the unit, which means there is no need for a storage tank.

Tankless whole house water heaters utilize gas or electric elements to heat water instantaneously. They can provide a consistent supply of hot water for multiple outlets simultaneously. Their compact size allows installation in smaller areas compared to traditional units.

According to the Energy Information Administration, tankless water heaters can save energy and costs, particularly for households with high hot water demands.

Some factors contributing to the appeal of tankless systems include rising energy costs, a growing focus on energy efficiency, and increasing home sizes that require more hot water capacity.

The American Council for an Energy-Efficient Economy reports that tankless water heaters can be up to 34% more energy-efficient for homes that use 41 gallons or less of hot water daily.

The shift to tankless systems can reduce energy consumption and carbon emissions, leading to environmental benefits. They can also increase property values due to their efficiency and longevity.

Health impacts include improved access to hot water for hygiene. Environmentally, these systems may reduce waste due to lower energy usage.

Implementing energy-efficient practices and technologies is essential for maximizing benefits. Recommendations include selecting units with suitable outputs and using professional installation services.

Investing in smart technology solutions, like energy management systems, can further enhance efficiency. Regular maintenance also ensures optimal performance and longevity of the systems.

What Are the Key Advantages of Using a Tankless Whole House Water Heater?

Tankless whole house water heaters offer several key advantages. They provide immediate hot water, save energy, and have a longer lifespan compared to traditional water heaters.

1. Energy Efficiency
2. Continuous Hot Water Supply
3. Space-Saving Design
4. Longer Lifespan
5. Reduced Risk of Water Damage
6. Environmental Benefits

The benefits of a tankless whole house water heater reflect various perspectives on efficiency, convenience, and environmental considerations.

1. Energy Efficiency:
   Energy efficiency refers to the reduced energy consumption associated with tankless water heaters. These systems heat water on demand, meaning they only use energy when hot water is required. The U.S. Department of Energy states that homeowners can save up to 30% on energy costs by switching to tankless models. This is significant, especially for larger households that frequently use hot water.

2. Continuous Hot Water Supply:
   A continuous hot water supply means that a tankless water heater can provide hot water for as long as needed, without interruption. Unlike traditional heaters that run out of hot water, tankless systems heat water instantaneously. This feature is crucial for larger families or during peak usage times, where multiple showers and appliances are in operation simultaneously.

3. Space-Saving Design:
   The space-saving design of tankless water heaters highlights their compact nature. These units can be installed on walls and require significantly less space compared to traditional tank models. Homeowners can reclaim valuable floor area in utility rooms or closets. According to the EPA, smaller systems contribute to overall home efficiency and appeal.

4. Longer Lifespan:
   A longer lifespan is a notable attribute of tankless water heaters. These units typically last about 20 years, which is nearly double the lifespan of traditional water heaters. This durability can lead to lower replacement costs over time, benefiting homeowners by reducing long-term expenses. Research by the Canadian Home Builders’ Association suggests that proper maintenance can extend the lifespan even further.

5. Reduced Risk of Water Damage:
   Reduced risk of water damage is associated with the absence of a bulky tank filled with water. If a traditional tank leaks or bursts, it can cause significant flooding and damage. Tankless systems mitigate this risk because they do not store large volumes of water. This is especially beneficial in areas prone to heavy rainfall or flooding.

6. Environmental Benefits:
   Environmental benefits arise from the energy savings and efficiency of tankless systems. By reducing energy consumption, these units lower greenhouse gas emissions associated with energy production. The Energy Information Administration notes that reducing energy use also lessens the demand for fossil fuels, promoting a cleaner environment. Therefore, tankless heaters align with sustainable practices and energy conservation efforts.

What Factors Should You Consider When Selecting the Best Tankless Whole House Water Heater?

When selecting the best tankless whole house water heater, consider a range of important factors including flow rate, energy efficiency, fuel type, installation space, and maintenance requirements.

1. Flow Rate
2. Energy Efficiency
3. Fuel Type
4. Installation Space
5. Maintenance Requirements

These factors can significantly influence your choice of a tankless water heater, according to various consumer preferences and a range of expert opinions.

1. Flow Rate: The flow rate refers to the amount of hot water the heater can provide per minute. Selecting a unit with the correct flow rate ensures that your household can meet its hot water needs. For example, a family of four typically requires a flow rate of at least 6-10 gallons per minute (GPM) to accommodate showers, dishwashing, and laundry simultaneously. Manufacturers often provide flow rate data which is crucial for determining suitability.

2. Energy Efficiency: Energy efficiency indicates how much energy the heater uses to produce hot water compared to the amount of hot water generated. Tankless water heaters generally have higher energy efficiency ratings than traditional tank heaters. Look for units with an Energy Factor (EF) rating. A higher EF indicates a more efficient model, potentially leading to lower utility bills over time.

3. Fuel Type: Tankless water heaters can be powered by electricity, natural gas, or propane. Electric units may have lower upfront costs but can be less efficient for larger households. Gas units, while often more efficient, require proper venting and installation considerations. The choice of fuel type can also depend on availability and local energy costs.

4. Installation Space: The available space for installation is an essential consideration. Tankless water heaters require less space than traditional units as they can be mounted on walls. Check the manufacturer’s specifications for size and necessary clearances, and consider whether indoor or outdoor installation is preferable for your situation.

5. Maintenance Requirements: Maintenance needs vary by model and type. Tankless heaters typically require regular descaling, especially in areas with hard water. Check the manufacturer’s recommendations for routine maintenance. Some models include features that simplify maintenance, such as built-in cleaning systems, which can save time and costs in the long run.

By carefully evaluating these factors, you can make an informed decision on the best tankless whole house water heater for your home.

What Essential Features Should You Look for in Reliable Tankless Whole House Water Heaters?

The essential features to look for in reliable tankless whole house water heaters include capacity, energy efficiency, flow rate, warranty, installation requirements, and safety features.

1. Capacity
2. Energy Efficiency Rating
3. Flow Rate
4. Warranty and Support
5. Installation Requirements
6. Safety Features

Understanding these features is crucial for making an informed purchasing decision.

1. Capacity:
   The capacity of a tankless water heater refers to the maximum amount of hot water it can deliver per minute. This is important for households with multiple showers or appliances running simultaneously. A standard whole house unit can provide 3 to 5 gallons per minute (GPM), depending on the heater size and heater setup. For example, a family of four might require a unit with a flow rate of at least 6 GPM for simultaneous use.

2. Energy Efficiency Rating:
   The energy efficiency rating indicates how effectively a unit converts fuel into hot water. Look for models with an Energy Factor (EF) or Uniform Energy Factor (UEF) rating, which help consumers gauge efficiency levels. Higher ratings generally mean lower utility bills. For instance, tankless models typically have an EF of 0.8 to 0.99, leading to significant energy savings compared to traditional tank-style heaters. Reports from the U.S. Department of Energy show that homeowners can save 24%–34% on energy costs by switching to tankless systems.

3. Flow Rate:
   Flow rate determines how much hot water a heater can provide at once. Consumers should assess their peak demand to select an appropriate model. Manufacturers usually provide GPM specifications for each model. For example, a model with a flow rate of 7 GPM can support two showers and a washing machine simultaneously.

4. Warranty and Support:
   A comprehensive warranty can provide peace of mind. Most reputable brands offer warranties ranging from 5 to 15 years on parts, with additional support for labor in the first year. This reflects the manufacturer’s confidence in their product’s longevity and reliability. Reviews and case studies often highlight customer satisfaction with responsive manufacturer support regarding warranty claims.

5. Installation Requirements:
   Proper installation is critical for optimal performance. Tankless units may require additional venting, gas lines, or electrical upgrades. Consumers should evaluate whether they can undertake the installation themselves or if they will need a professional. Research indicates that professional installation can lead to longer lifespan and efficiency, as opposed to DIY attempts that might violate warranty agreements.

6. Safety Features:
   Safety features ensure the safe operation of the heater. Look for models with features such as automatic shut-off, overheat protection, and leak detection. Advanced models may include digital displays and Wi-Fi connectivity for monitoring and control. These features contribute to household safety and can help detect potential failures before they escalate into problems.

What Are the Most Recommended Models for Large Capacity Tankless Whole House Water Heaters?

The most recommended models for large capacity tankless whole house water heaters include the following brands and features.

1. Rinnai RSC199iN
2. Noritz NRC661-DV
3. Uponor Ecoflex
4. Stiebel Eltron Tempra Plus
5. Takagi T-H3S
6. Rheem Prestige

The primary features to consider vary widely among these tankless water heaters. Each model offers unique advantages, including efficiency ratings, flow rates, installation options, and technology. Furthermore, some models might include advanced features such as remote control capabilities, Wi-Fi connectivity, and self-diagnostics.

1. Rinnai RSC199iN:
   The Rinnai RSC199iN is a high-efficiency model known for its compact design and excellent flow rate. It provides up to 199,000 BTU for heating, resulting in a flow rate of 9.8 gallons per minute at a 35°F temperature rise. Rinnai reports a Uniform Energy Factor (UEF) of 0.96, making it highly efficient in energy consumption. Additionally, it features an advanced technology for ease of use, including Wi-Fi control options through the Rinnai app.

2. Noritz NRC661-DV:
   The Noritz NRC661-DV is another well-regarded option, providing up to 6.6 gallons per minute at a 35°F rise. This model uses a Direct Vent system, which allows for flexible installation options. It has a UEF of 0.94, and Noritz highlights its durability and longevity. The direct venting also minimizes indoor air pollution, making it a good choice for indoor installations.

3. Uponor Ecoflex:
   Uponor Ecoflex is designed for larger homes and commercial applications. It includes insulated PEX tubing capable of maintaining temperature over distances. This centralized heating solution can manage significant demand effectively, with overall performance being highly dependent on installed systems. Uponor’s patented technology maximizes efficiency and reduces heat loss.

4. Stiebel Eltron Tempra Plus:
   Stiebel Eltron’s Tempra Plus employs advanced flow control technology. This model ensures that water temperature remains consistent despite fluctuating water demands. It boasts a UEF of up to 0.99, indicating remarkable energy efficiency. The Tempra Plus is ideal for homes with high hot water demands, combining efficiency with reliability.

5. Takagi T-H3S:
   The Takagi T-H3S model offers up to 10 gallons per minute, making it suitable for larger households. It features a UEF of 0.95, and its compact size permits easy installation in tight spaces. This model also emphasizes safety features, including freeze protection and overheating shutoff.

6. Rheem Prestige:
   Rheem Prestige provides advanced connectivity with Wi-Fi monitoring as part of its features. It is capable of delivering up to 10 gallons per minute for hot water needs. With a UEF also around 0.94, this model balances powerful performance with energy savings. Rheem also provides a range of venting options, which may increase its installation flexibility.

Consumers should evaluate their specific hot water needs, house size, and installation setup when choosing among these models. Each model’s combination of efficiency ratings, performance capabilities, and features can significantly affect the overall satisfaction of the homeowner.

What Installation and Maintenance Tips Can Help You Get the Most Out of a Tankless Whole House Water Heater?

To optimize the performance and longevity of a tankless whole house water heater, consider installation and maintenance tips that enhance efficiency.

1. Proper Sizing
2. Location Consideration
3. Ventilation Requirements
4. Regular Descaling
5. Filter Maintenance
6. Temperature Setting
7. Electrical and Gas Supply Check

These tips contribute to the effective functioning and sustainability of your heater, but there are different perspectives on how to prioritize them. Some believe regular descaling is crucial for longevity, while others argue that ensuring proper sizing yields better efficiency.

1. Proper Sizing:
   Proper sizing of a tankless water heater ensures it can meet the household’s hot water demand without excessive energy consumption. Manufacturers provide sizing guides based on flow rates in gallons per minute. Selecting the correct unit prevents the heater from overworking, which leads to early wear and energy inefficiency.

2. Location Consideration:
   Location consideration plays a crucial role in installation. Tankless water heaters work best in sheltered areas to protect them from the elements. Installing the unit close to usage points reduces heat loss in pipes. A well-chosen location leads to increased efficiency and quicker hot water delivery.

3. Ventilation Requirements:
   Ventilation is vital for gas-powered tankless heaters to prevent harmful gas buildup. Adequate ventilation channels fresh air and expels exhaust. Install venting following manufacturer specifications. Inadequate ventilation can lead to safety hazards or decreased efficiency.

4. Regular Descaling:
   Regular descaling prevents mineral buildup, which can impede water flow and damage heating elements. Hard water areas should descale every six months to one year. Using a descaling solution can correct this issue. Neglecting this maintenance can result in reduced efficiency and increased operational costs.

5. Filter Maintenance:
   Filter maintenance keeps water free of debris and sediment, which can damage components. Many units have pre-filters that should be cleaned or replaced regularly. Adhering to a filter maintenance schedule ensures water quality and prolongs equipment life.

6. Temperature Setting:
   Setting the water temperature correctly enhances safety and efficiency. For most households, a setting of 120°F is adequate for comfort while minimizing scalding risks and energy consumption. Adjusting the temperature downwards can save energy, while a higher setting can unnecessarily increase bills.

7. Electrical and Gas Supply Check:
   A thorough electrical and gas supply check ensures the heater operates at optimal capacity. Ensure the unit is connected to the right voltage and that gas lines are unobstructed. Regular checks reduce the risk of malfunctions and can lead to lower energy costs.

Implementing these installation and maintenance tips helps ensure that a tankless whole house water heater functions efficiently and lasts longer.

What Do Reviews and Customer Feedback Reveal About the Best Tankless Whole House Water Heaters?

The reviews and customer feedback reveal that the best tankless whole house water heaters offer efficient performance, reliability, and technological features for optimal water heating.

1. Energy efficiency
2. Flow rate capacity
3. Size and installation space
4. Temperature control features
5. Brand reputation and customer support
6. Cost and long-term savings
7. Maintenance requirements
8. User-friendly controls

Customer feedback often highlights a diverse range of experiences and opinions regarding these attributes, presenting various perspectives on which features hold more importance based on household needs.

1. Energy Efficiency: Energy efficiency is a key factor for the best tankless whole house water heaters. Customers prefer units that significantly lower energy consumption compared to traditional tank heaters. According to the U.S. Department of Energy, tankless water heaters can be 24% to 34% more energy efficient for homes that use 41 gallons or less of hot water daily.

2. Flow Rate Capacity: Flow rate capacity refers to the amount of hot water a unit can provide per minute. Customers often report frustrations with low flow rates, especially during peak usage times. A study by Energy Star indicates that the average peak demand for hot water in a residential setting is typically around 3-5 gallons per minute.

3. Size and Installation Space: The physical dimensions of tankless water heaters are critical in customer reviews. Many consumers appreciate compact designs that save space in small homes or apartments. This flexibility in installation is often highlighted in case studies, such as residential conversions where space was limited.

4. Temperature Control Features: Good temperature control mechanisms enhance user satisfaction. Many reviewers favor models with digital thermostats that allow precise temperature settings. An analysis by Consumer Reports demonstrates that consistent water temperatures significantly improve the overall experience.

5. Brand Reputation and Customer Support: Brand reputation plays a crucial role in customer confidence. Feedback often emphasizes the significance of strong customer support systems. Brands with higher ratings in user satisfaction tend to have better warranties and responsive support teams.

6. Cost and Long-term Savings: Consumers frequently evaluate the initial purchase cost against long-term savings on energy bills. Reviews reveal that investing in a high-quality tankless water heater leads to reduced utility bills. Research by the National Renewable Energy Laboratory states that tankless systems have an average lifespan of over 20 years, making them a cost-effective option in the long run.

7. Maintenance Requirements: Maintenance needs affect consumer satisfaction. Easy-to-maintain models receive favorable reviews. Regular descaling and filter changes can prevent breakdowns, and user feedback often mentions how accessible maintenance guidelines are for specific brands.

8. User-friendly Controls: User-friendly controls enhance the overall experience. Many customers appreciate intuitive interfaces and easy-to-navigate settings. Reviews reveal that advanced features, such as smartphone connectivity and remote monitoring, are appealing to tech-savvy consumers.

These attributes provide a comprehensive understanding of what customers prioritize when selecting tankless whole house water heaters.

Related Post:

• Best lowboy electric water heater
• Best water heated mattress pad
• Best tankless natural gas water heater
• Best heated water bowl
• Best commercial tankless water heater