Back to blogs

Understanding Electric Tankless Water Heater Power Requirements

When it comes to choosing a water heater for your home, electric tankless water heaters have become increasingly popular. Not only do they provide on-demand hot water, but they also offer significant advantages in terms of energy efficiency, convenience, longevity, and value. However, it is important to understand the power requirements of electric tankless water heaters to ensure optimal performance and avoid any potential issues.

Unlike traditional storage water heaters that have a limited supply of hot water, tankless water heaters heat water as it flows through the unit, providing endless hot water on demand. To ensure that the tankless water heater can meet the hot water demand of your household, proper sizing is crucial. The size of a tankless water heater is determined by its flow rate, which is measured in gallons per minute (GPM). Additionally, you need to consider the temperature rise, which is the difference between the groundwater temperature and the desired hot water temperature.

Proper sizing and installation are essential for a tankless water heater to deliver the endless hot water you desire. In this article, we will delve deeper into the power requirements of electric tankless water heaters, how they work, and important considerations for sizing and installation. By understanding these key aspects, you can make an informed decision and ensure that your electric tankless water heater meets your specific hot water needs.

Key Takeaways:

  • Electric tankless water heaters provide on-demand hot water and offer advantages in efficiency, convenience, longevity, and value.
  • Proper sizing of a tankless water heater is crucial to meet the hot water demand of your household.
  • The flow rate in gallons per minute (GPM) and the temperature rise are important factors to consider when sizing a tankless water heater.
  • Electric tankless water heaters instantly heat cold water as it flows through a heat exchanger inside the unit.
  • Consulting a professional for installation and considering the power requirements, including breaker size and wiring, is recommended.

What is a Tankless Water Heater?

A tankless water heater is a revolutionary system that provides hot water on demand, eliminating the need for a storage tank like traditional water heaters. Unlike storage water heaters that constantly heat and maintain a specific supply of hot water, tankless water heaters heat water as it flows through the unit. This means that hot water is available whenever you need it, without the limitations of a tank.

With a tankless water heater, you can enjoy the convenience of on-demand hot water, whether you're taking a shower, doing laundry, or washing dishes. These units can run on either natural gas, propane, or electricity to heat the water. They are typically compact in size and can be mounted on a wall, freeing up valuable space in your home.

"A tankless water heater is a game-changer when it comes to hot water supply. No longer do you have to wait for the storage tank to refill or worry about running out of hot water. With a tankless unit, you have an endless supply of hot water at your fingertips."

Not only do tankless water heaters offer the advantage of on-demand hot water, but they also provide energy savings. Since they only heat water when it is needed, they eliminate standby heating costs associated with storage water heaters. This can result in significant energy savings over time, making tankless water heaters an eco-friendly choice for your home.

https://www.youtube.com/watch?v=RLMFrEp7S8k

Comparison between Tankless Water Heaters and Storage Water Heaters:

Tankless Water Heater Storage Water Heater Hot Water Supply On-demand hot water Limited supply based on tank sizeEnergy Efficiency High energy efficiency, no standby heating costs Lower energy efficiency due to standby heating Space Requirement Compact and wall-mountable Requires a dedicated space for a storage tank Lifespan Longer lifespan Shorter lifespan Installation Cost Higher initial cost Lower initial cost

When considering a new water heater for your home, it's important to weigh the advantages of a tankless water heater, such as on-demand hot water and energy savings, against the benefits of a storage water heater, such as lower upfront cost and simplicity. Ultimately, the choice depends on your specific needs and preferences.

How Does a Tankless Water Heater Work?

Tankless water heaters provide hot water instantly by heating it as it flows through a heat exchanger inside the unit. When you turn on a hot water faucet or start an appliance that uses hot water, cold water enters the tankless water heater through the cold water inlet. The water then flows through the heat exchanger, which rapidly heats it to the desired temperature. This instant heating process, known as "flash burning," allows the tankless water heater to provide hot water on demand.

This on-demand heating system eliminates the need for a storage tank, making tankless water heaters more energy-efficient and space-saving compared to traditional storage water heaters. The hot water flows from the tankless water heater to its intended destination, such as a shower or dishwasher, and exits the faucet or valve at the desired temperature.

"Tankless water heaters offer the advantage of providing hot water whenever you need it. With their instant heating capability, you no longer have to worry about running out of hot water or waiting for it to heat up."

The heat exchanger in a tankless water heater can be powered by electricity, natural gas, or propane, depending on the model. It is important to consider the power source and availability when choosing a tankless water heater that suits your needs. Regardless of the power source, tankless water heaters offer the convenience of continuous hot water supply without the limitations of a limited storage capacity, providing a more efficient and reliable solution for your hot water needs.

tankless water heater

Advantages of Tankless Water Heaters:

  • Instant hot water on demand
  • Energy-efficient
  • Space-saving installation
  • No standby heating costs
  • Endless supply of hot water
  • Longer lifespan compared to storage water heaters

Disadvantages of Tankless Water Heaters:

  • May not meet the hot water demand of multiple fixtures operating simultaneously
  • Reduces efficiency with significant temperature rise requirements
  • Requires proper sizing and installation

Key Points:

  • Tankless water heaters provide hot water instantly by heating it as it flows through a heat exchanger.
  • They eliminate the need for a storage tank, making them more energy-efficient and space-saving.
  • Tankless water heaters can be powered by electricity, natural gas, or propane, depending on the model.
  • They offer the advantage of continuous hot water supply without the limitations of a storage tank.

Sizing a Tankless Water Heater Properly

Properly sizing a tankless water heater is essential to ensure it can meet the hot water demand of a household. The key factors to consider are the flow rate and the temperature rise. The flow rate, measured in gallons per minute (GPM), determines the amount of hot water the tankless water heater can provide. For smaller households, a flow rate of 2-5 GPM is usually sufficient, while larger households may require a higher flow rate of 6-10 GPM.

Additionally, it is crucial to consider the temperature rise, which is the difference between the groundwater temperature and the desired hot water temperature. A greater temperature rise requires a larger and more powerful tankless water heater to meet the demand. By accurately sizing the tankless water heater based on the flow rate and temperature rise, homeowners can ensure optimal performance and a continuous supply of hot water.

To illustrate the importance of sizing, let's consider an example. Suppose a household consists of two bathrooms, a kitchen, and a laundry room with a total hot water demand of 6 GPM. If the temperature rise required is 40 degrees Fahrenheit, a tankless water heater with a flow rate of 6 GPM and the ability to achieve a temperature rise of 40 degrees Fahrenheit is suitable for this household.

Household Hot Water Demand Flow Rate (GPM) Temperature Rise (°F) Tankless Water Heater Sizing Small 2-5 20-30 Recommended flow rate and temperature rise Medium 5-8 30-40 Increased flow rate and temperature rise Large 8-12 40+ High flow rate and temperature rise

Reasons to Choose a Tankless Water Heater

When considering a new water heater for your home, a tankless water heater can offer several advantages. Here are some compelling reasons to choose a tankless water heater:

  1. Energy Efficiency: Tankless water heaters are highly energy-efficient, helping to lower your energy bills. Unlike traditional storage water heaters that constantly heat and maintain a large volume of water, tankless water heaters only heat water as it is needed. This on-demand heating reduces energy waste and ensures that you only pay for the hot water you use.
  2. Savings: By using less energy, tankless water heaters can result in significant savings over time. Although the initial cost of a tankless water heater may be higher than a traditional storage water heater, the energy savings can help offset this expense in the long run. Additionally, tankless water heaters have a longer lifespan, reducing the need for frequent replacements and providing additional cost savings over time.
  3. Convenience: Tankless water heaters provide hot water on demand, eliminating the need to wait for a storage tank to heat up. This convenience is especially beneficial for households with multiple occupants or high hot water demand. With a tankless water heater, you can enjoy endless hot water whenever you need it.
  4. Longevity: Tankless water heaters are built to last. With proper maintenance and care, they can have a lifespan of 20 years or more. This durability not only saves you money on replacements but also reduces the environmental impact by reducing waste.
  5. Value: Investing in a tankless water heater can increase the value of your home. Potential buyers often prefer homes with energy-efficient features, and a tankless water heater can be an attractive selling point. Additionally, the long lifespan and energy savings of a tankless water heater can add value to your investment over time.

Considering these reasons, a tankless water heater can be a wise choice for homeowners looking to improve energy efficiency, save money, enjoy convenience, ensure longevity, and enhance the value of their home.

Limitations of Tankless Water Heaters

Tankless water heaters offer many advantages, but it is important to understand their limitations as well. One key limitation is their ability to meet the hot water demand of multiple fixtures operating simultaneously. If the hot water demand exceeds the flow rate of the tankless water heater, it may struggle to provide hot water to all fixtures at once. This can be a concern in larger households or during peak usage times. Proper sizing and consideration of the hot water demand are crucial to ensure optimal performance.

Another limitation to consider is the temperature rise required. The temperature rise is the difference between the groundwater temperature and the desired hot water temperature. If a significant temperature rise is needed, it may reduce the overall efficiency of the tankless water heater. It is essential to select a tankless water heater that can handle the required temperature rise to ensure adequate hot water supply.

In summary, while tankless water heaters offer many benefits, it is important to be aware of their limitations. Understanding the hot water demand of your household and selecting a properly sized tankless water heater can help overcome these limitations and ensure a consistent supply of hot water.

https://www.youtube.com/watch?v=8FVT7UHph9w

Key Limitations of Tankless Water Heaters:

  • Hot water demand may exceed flow rate, leading to inadequate supply to multiple fixtures.
  • Significant temperature rise requirements may reduce overall efficiency.

Electric Tankless Water Heater Installation Tips

Proper installation is crucial for the safe and efficient operation of an electric tankless water heater. When it comes to installing an electric tankless water heater, it is always recommended to hire a professional for the job. They have the expertise and knowledge to ensure that the installation is done correctly and in compliance with all safety regulations.

One important aspect of electric tankless water heater installation is understanding the power requirements. This includes determining the appropriate breaker size and wiring. The breaker size is determined by the amp requirement of the tankless water heater, which can be calculated using the power formula. It is important to use the correct wire size and ensure that the breaker panel can handle the electrical load of the tankless water heater.

When choosing the installation location for your electric tankless water heater, it is important to consider its proximity to the water main. This ensures quick heating of the water and minimizes any heat loss in the plumbing system. Additionally, make sure that the installation complies with local codes and regulations to ensure the safety and efficiency of the system.

Installation Tips for Electric Tankless Water HeatersNotes1. Hire a professionalEnsure proper installation and compliance with safety regulations.2. Determine the appropriate breaker sizeCalculate the amp requirement using the power formula.3. Use the correct wire sizeEnsure the electrical load is properly supported.4. Choose an installation location near the water mainMinimize heat loss in the plumbing system.5. Comply with local codes and regulationsEnsure safety and efficiency of the system.

By following these installation tips, you can ensure the safe and efficient operation of your electric tankless water heater. Remember, professional installation is always recommended to ensure that the system is set up correctly and to avoid any potential issues or hazards.

Picking the Correct Breaker Size for an Electric Tankless Water Heater

When it comes to the safe and efficient operation of an electric tankless water heater, selecting the correct breaker size is crucial. The breaker size is determined by the amp requirement of the heater, which can be calculated using a simple power formula. By dividing the wattage of the tankless water heater by the voltage, the breaker size can be determined. It is important to consider safety regulations and not exceed 80% of the breaker's total capacity to prevent potential fires.

electric tankless water heater

Calculating the correct breaker size ensures that the electrical load of the tankless water heater is adequately supported. This helps prevent overload and overheating, reducing the risk of electrical hazards. The breaker panel should be able to handle the electrical load of the tankless water heater to ensure proper functioning and safety. A licensed electrician can help determine the appropriate breaker size and ensure compliance with safety regulations.

Example Power Formula Calculation:

Heater Wattage Breaker Size Calculation 8000 watts (8000 watts) / (240 volts) = 33.33 amps 10000 watts (10000 watts) / (240 volts) = 41.67 amps

It is important to note that the calculated breaker size should not be the exact value. The breaker size available in the market may not match the calculated value exactly. In such cases, it is recommended to choose the next higher available breaker size. This ensures that the breaker can handle the required electrical load safely and effectively.

Can My House Handle an Electric Tankless Water Heater?

Before installing an electric tankless water heater in your house, it is important to determine if your electrical system can handle the increased power requirements. This assessment is crucial to ensure the safe and efficient operation of the tankless water heater. We recommend consulting a professional electrician to evaluate your house's breaker panel and electrical system compatibility with the tankless water heater.

Upgrading the breaker panel may be necessary to accommodate the electrical load of the tankless water heater. A professional consultation will help determine the overall power input and specific needs of the tankless water heater, taking into account factors such as the size of the breaker panel, climate, and daily water usage. The electrician can recommend the appropriate panel size and make any necessary adjustments to ensure a successful installation.

By consulting a professional, you can ensure that your house is properly equipped to handle the power requirements of an electric tankless water heater. This will help prevent any electrical issues, ensure the longevity of the tankless water heater, and provide you with endless hot water for your household needs.

Benefits of Consulting a Professional

  • Accurate assessment of your house's electrical system
  • Proper sizing and selection of the tankless water heater
  • Identification of any necessary upgrades or modifications to the breaker panel
  • Ensured safety and compliance with electrical codes
  • Prolonged lifespan and optimal performance of the tankless water heater

Can I Calculate the Correct Breaker Sizing for My Electric Tankless Water Heater?

When installing an electric tankless water heater, it's essential to ensure that the breaker size is appropriate for the electrical load. By calculating the correct breaker sizing, you can ensure safe and efficient operation of your tankless water heater.

The formula for calculating the breaker size is straightforward. First, determine the voltage of your electric tankless water heater, which is typically 240 volts. Then, divide the wattage of the tankless water heater by the voltage. The result will be the maximum amp required for the heating element.

For example, let's say your electric tankless water heater has a wattage of 10,000 watts. Dividing this by 240 volts gives you a maximum amp requirement of 41.67 amps. Therefore, a 50 amp breaker would be appropriate for this particular tankless water heater.

Breaker Sizing Calculation Example

Electric Tankless Water Heater Information Calculation Breaker Size Wattage: 10,000 watts 10,000 watts ÷ 240 volts = 41.67 amps 50 amps

It's important to note that while this calculation provides a general guideline for breaker sizing, it's crucial to follow safety regulations and not exceed the recommended capacity. If you're unsure about the breaker size or if your specific situation requires additional considerations, it's always best to consult with a licensed electrician for professional guidance.

https://www.youtube.com/watch?v=bD0KLBOM2tw

Do Tankless Water Heaters Need a Dedicated Circuit?

One common question homeowners have when considering a tankless water heater is whether it requires a dedicated circuit. The answer is that while tankless water heaters do not necessarily need a dedicated circuit, there are situations where establishing one may be necessary.

When determining if a dedicated circuit is needed, it is essential to consider the electrical load of the tankless water heater and the other electrical devices in the area. If the tankless water heater is installed in an area with a high electrical load, such as a bathroom with multiple fixtures running simultaneously, a dedicated circuit may be required to ensure an adequate power supply. This helps prevent potential issues like circuit overload and ensures that the tankless water heater can operate efficiently.

Consulting a professional electrician is highly recommended to assess the specific electrical needs of your tankless water heater installation. They can evaluate the electrical load, determine if a dedicated circuit is necessary, and provide guidance on the best electrical setup for your specific situation.

It is important to remember that safety should always be a top priority when dealing with electrical systems, and following the advice of a licensed electrician can help ensure a safe and efficient operation of your tankless water heater.

Dangers of Having the Wrong-Sized Breaker

Having the wrong-sized breaker for your electric tankless water heater can lead to potential dangers, including the risk of an electrical fire. Breakers serve as safety devices that protect against excessive current flow, preventing overheating and electrical hazards. When it comes to breakers, size matters.

If the breaker is too small for the electrical load of the tankless water heater, it may trip frequently and fail to provide adequate protection. This can result in overheating of the electrical components and potentially lead to an electrical fire. On the other hand, if the breaker is too large, it may not trip when it should, allowing an overload of current that can cause damage to the heater and pose a fire hazard.

It is essential to ensure the breaker size is appropriate for the electrical load of the tankless water heater. Following safety regulations and guidelines is crucial to prevent any potential hazards. If you are unsure about the breaker size or installation requirements, it is always recommended to consult a licensed electrician for professional assistance. They can help assess your specific situation, determine the correct breaker size, and ensure safe operation of your electric tankless water heater.

Table: Comparison of Breaker Sizes and Electrical Loads

Breaker Size Electrical Load 20 Amps 2400 Watts 30 Amps 3600 Watts 40 Amps 4800 Watts

"Using the correct breaker size is crucial for the safe and efficient operation of your electric tankless water heater. Don't take any risks when it comes to electrical safety. Always consult a licensed electrician for expert advice and installation."

Should I Have an Electric Water Heater or Gas Water Heater?

When it comes to choosing between an electric water heater and a gas water heater, there are a few factors to consider. Energy efficiency, cost savings, and lifespan are some of the key considerations that can help you make an informed decision for your home.

Electric water heaters are generally more energy-efficient than their gas counterparts. They convert more energy into heat, resulting in lower energy bills over time. Additionally, electric water heaters have a longer lifespan compared to gas water heaters, which means fewer replacements and potential savings in the long run.

While natural gas is often cheaper than electricity, the higher efficiency of electric water heaters offsets the cost difference, resulting in greater overall savings on monthly utility bills. It's important to note that gas water heaters may be cheaper to install initially, but their lower energy efficiency and shorter lifespan may result in higher costs in the long term.

Comparison Table: Electric Water Heater vs. Gas Water Heater

Electric Water Heater Gas Water Heater Energy Efficiency High Lower Monthly Savings Greater Lower Lifespan Longer Shorter Installation Cost Higher Lower

"While natural gas may be cheaper, electric water heaters offer higher energy efficiency and longer lifespans, resulting in greater overall savings."

Ultimately, the choice between an electric water heater and a gas water heater depends on your specific needs and circumstances. If energy efficiency, long-term savings, and durability are important to you, an electric water heater may be the better choice. However, if upfront installation costs and natural gas availability are significant factors, a gas water heater might be more suitable. We recommend consulting a professional to assess your home's requirements and provide expert guidance in selecting the right water heater for your needs.

Summing Up

In conclusion, electric tankless water heaters offer a range of advantages, including energy efficiency, on-demand hot water, and space-saving installation. However, it is crucial to consider the power requirements, proper sizing, and professional installation to ensure optimal performance and safety.

When it comes to electric tankless water heaters, sizing plays a vital role. Determining the correct size involves considering the hot water demand of your household, flow rate, and temperature rise. Hiring a professional to assess your needs and recommend the appropriate size is essential for endless hot water.

During installation, attention should be given to the breaker size and wiring. The breaker size should be calculated using the amp requirement of the tankless water heater, ensuring it complies with safety regulations and prevents potential hazards. Consulting a licensed electrician is highly recommended to handle these electrical requirements properly.

By prioritizing safety and taking into account the power requirements, sizing, and installation considerations, you can confidently select and enjoy the benefits of an electric tankless water heater in your home.

FAQ

What are the power requirements for an electric tankless water heater?

The power requirements for an electric tankless water heater depend on the specific model and its electrical load. It is important to consult the manufacturer's specifications and consider the breaker size, wiring, and overall electrical system compatibility.

What is a tankless water heater?

A tankless water heater is a system that provides hot water on demand, without the need for a storage tank. It heats water as it flows through the unit, eliminating standby heating costs and saving energy.

How does a tankless water heater work?

When a hot water faucet is turned on or an appliance requiring hot water is used, cold water flows into the tankless water heater. The water passes through a heat exchanger, where it is rapidly heated to the desired temperature. The hot water then flows to its intended destination.

How do I properly size a tankless water heater?

Proper sizing of a tankless water heater involves determining the flow rate, measured in gallons per minute (GPM), and considering the temperature rise required to meet the hot water demand of the household.

Why should I choose a tankless water heater?

Tankless water heaters offer advantages in energy efficiency, cost savings, convenience, longevity, and value. They provide hot water on demand, eliminate standby heating costs, and can be mounted on a wall, saving space.

What are the limitations of tankless water heaters?

Tankless water heaters may have limitations in meeting the hot water demand of multiple fixtures operating simultaneously and in handling significant temperature rises. Proper sizing and consideration of these limitations are essential for optimal performance.

What should I consider during the installation of an electric tankless water heater?

Proper installation of an electric tankless water heater involves considering the power requirements, including breaker size and wiring. It is recommended to hire a professional for the installation process to ensure safety and efficiency.

How do I pick the correct breaker size for an electric tankless water heater?

Lightning fast quotes.

Our water heater experts are standing by to help. Complete our form or call to schedule service.

Get a quoteA picture of a water heaters now technician.