How Hard Is It To Install A Tankless Water Heater?

Installing a tankless water heater can be difficult, requiring professional expertise due to complex electrical and plumbing requirements. This article will explore the factors to consider, such as electrical capacity, gas supply, and venting, as well as the potential need for retrofitting.

Additionally, we’ll discuss the advantages of hiring a professional to ensure proper installation, prolonging the lifespan of the unit and maximizing energy efficiency. With the rise in demand for eco-friendly and cost-effective heating solutions, understanding the intricacies of installing a tankless water heater is crucial for homeowners looking to upgrade their systems.

So, let’s delve into the details and make your installation process hassle-free.

How Hard Is It To Install A Tankless Water Heater?


Benefits Of A Tankless Water Heater

Tankless water heaters, also known as on-demand water heaters, are gaining popularity among homeowners due to their numerous benefits.

Energy Efficiency

  • Tankless water heaters are highly energy efficient compared to traditional water heaters with tanks. They only heat the water when it is needed, saving energy and reducing utility bills.
  • As there is no water storage, the standby energy loss commonly associated with tank water heaters is eliminated. This further enhances the energy efficiency of tankless water heaters.
  • According to the u.s. department of energy, tankless water heaters can be up to 34% more energy efficient than conventional tank water heaters.

Continuous Hot Water Supply

  • One of the major advantages of tankless water heaters is their ability to provide a continuous supply of hot water. Gone are the days of waiting for the tank to refill and heat up again.
  • Tankless water heaters heat the water on demand, providing an uninterrupted flow of hot water for as long as needed.
  • This is especially beneficial for larger households where multiple hot water sources may be used simultaneously, such as showers, laundry, and dishwashing.

Space-Saving Design

  • Tankless water heaters have a compact and space-saving design compared to traditional tank water heaters.
  • With no need for a large storage tank, tankless water heaters can be wall-mounted or placed in tight spaces, allowing for better utilization of available space in your home.
  • Their sleek and modern design blends seamlessly with any interior decor, without compromising on performance and efficiency.

Tankless water heaters offer numerous benefits such as energy efficiency, continuous hot water supply, and space-saving design. By implementing this innovative technology, homeowners can enjoy a more convenient and cost-effective hot water solution. upgrade to a tankless water heater and experience the difference it makes in your daily life.

Evaluating Your Household’S Hot Water Needs

Tankless water heaters have gained popularity in recent years due to their energy efficiency and endless supply of hot water. If you’re considering installing a tankless water heater in your home, you may be wondering how hard it is to undertake such a project.

In this section, we will delve into evaluating your household’s hot water needs before you make the leap to a tankless water heater. Let’s analyze water usage patterns and determine the required flow rate.

Analyzing Water Usage Patterns

Understanding your household’s water usage patterns is crucial when deciding on a tankless water heater. Here are a few key points to consider:

  • Peak usage times: Take note of the busiest periods in your home when hot water is in high demand. This includes mornings when everyone is getting ready, or evenings when multiple appliances are running simultaneously.
  • Duration of hot water usage: Determine the typical length of time you use hot water for tasks like showers, washing dishes, or doing laundry.
  • Number of hot water outlets: Make a list of all the hot water outlets in your home, such as showers, faucets, and appliances, to get an idea of how many simultaneous hot water demands may occur.

By analyzing these usage patterns, you’ll gain insights into how much hot water your household requires and the peak flow rate needed to meet that demand.

Determining The Required Flow Rate

The flow rate is the amount of hot water a tankless water heater can deliver at a given time. To calculate the required flow rate for your household, consider the following:

  • Add up simultaneous hot water demands: Determine the total flow rate required when multiple hot water outlets are being used simultaneously.
  • Consult appliance specifications: Check the flow rate requirements of specific appliances like showers, faucets, or dishwashers.
  • Understand temperature rise: Calculate the temperature rise required by subtracting the incoming water temperature from the desired hot water temperature.

Once you have these figures, you can choose a tankless water heater with an appropriate flow rate that meets your household’s hot water needs.

Remember, evaluating your household’s hot water needs is an essential step in installing a tankless water heater. By understanding your usage patterns and determining the required flow rate, you’ll be well-prepared to choose the right tankless water heater for your home.

Choosing The Right Size And Type Of Tankless Water Heater

Gas Vs. Electric Tankless Water Heaters

When it comes to choosing a tankless water heater, one of the first decisions you’ll need to make is whether to go with a gas or electric model. Each type has its pros and cons, so it’s important to understand the differences before making a decision.

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Here are the key points to consider:

  • Gas tankless water heaters:
  • Pros:
  • Generally have higher flow rates, making them ideal for larger households with high hot water demand.
  • Provide instant hot water, as they heat water on demand.
  • Can continue to supply hot water during power outages.
  • Cons:
  • Installation can be more complex and costly, as they require a gas line and proper venting.
  • Regular maintenance is essential to ensure safety and optimal performance.
  • Initial cost may be higher compared to electric models.
  • Electric tankless water heaters:
  • Pros:
  • Simple installation, as they only require a dedicated electrical circuit.
  • Lower upfront costs compared to gas models.
  • Compact size, allowing for flexible installation options.
  • Cons:
  • Lower flow rates compared to gas models, which may not be suitable for larger households.
  • May experience a slight delay in hot water delivery compared to gas models.
  • Power outages can disrupt the hot water supply.

Sizing Considerations Based On Household Size And Demand

Choosing the right size of tankless water heater is crucial to ensure that it can meet your household’s hot water needs. Here are some factors to consider:

  • Household size:
  • The number of people in your household will impact the demand for hot water. Larger households with more people will typically require a higher flow rate.
  • Consider the peak hot water demand in your home, such as simultaneous showers or running multiple appliances that require hot water.
  • Flow rate:
  • Calculate the flow rate required for your household by determining the number of fixtures that will be using hot water simultaneously.
  • Use flow rate charts provided by manufacturers to choose a tankless water heater with the appropriate flow rate.
  • Temperature rise:
  • Determine the temperature rise needed to achieve your desired hot water temperature. This is the difference between the incoming cold water temperature and the desired hot water temperature.
  • Consider your climate and the temperature of your groundwater, as colder climates may require a higher temperature rise.
  • Efficiency ratings:
  • Look for tankless water heaters with higher energy efficiency ratings, such as an energy factor (ef) for electric models or the uniform energy factor (uef) for gas models. Higher ratings indicate better energy efficiency and lower operating costs.

By considering these sizing considerations and understanding the differences between gas and electric tankless water heaters, you can make an informed decision that meets your household’s hot water demands while maximizing energy efficiency. Remember to consult with a qualified professional to ensure proper installation and size selection.

Preparing For The Installation Process

Tankless water heaters are gaining popularity due to their energy efficiency and endless hot water supply. If you’re considering installing one in your home, you might be wondering how hard the installation process will be. Well, fear not! In this section, we’ll discuss the necessary steps to prepare for the installation of a tankless water heater.

From gathering the tools and materials to shutting off the water and gas/electricity supply, we’ve got you covered.

Gathering Necessary Tools And Materials

Before you begin the installation process, it’s crucial to ensure you have all the necessary tools and materials on hand. Here are the key points to keep in mind:

  • Make a checklist of required tools and materials: To avoid any delays or last-minute trips to the hardware store, create a checklist of everything you’ll need. This typically includes a pipe cutter, adjustable wrench, pipe fittings, teflon tape, and a voltage tester.
  • Measure the space: Take accurate measurements of the available space where the tankless water heater will be installed. This will help determine the appropriate size and ensure a proper fit.
  • Check the manufacturer’s instructions: Different tankless water heaters may have specific requirements for installation. Review the manufacturer’s instructions to identify any additional tools or materials that may be needed.
  • Purchase necessary permits: Depending on your location, you may need to obtain permits before installing a tankless water heater. Check with your local building department for any regulations or guidelines you need to adhere to.

Shutting Off The Water And Gas/Electricity Supply

Before beginning the installation process, it’s crucial to turn off the water and gas or electricity supply to ensure safety. Here are the key points to keep in mind:

  • Locate the main shutoff valves: Find the main water shutoff valve and turn it off. This will stop the water supply to your entire house. Additionally, locate the gas shutoff valve or turn off the electricity to disconnect the power supply.
  • Drain any remaining water: Release any remaining water pressure in the pipes by opening a nearby faucet. This will prevent water from spraying when disconnecting the old water heater.
  • Turn off the gas/electricity supply: If you have a gas-powered tankless water heater, turn off the gas supply using the gas shutoff valve. For an electric tankless water heater, switch off the breaker in the electrical panel to cut off the power supply.
  • Follow safety precautions: When dealing with gas or electricity, it’s important to take safety precautions. Ensure proper ventilation for gas heaters and wear protective gloves and goggles when handling electrical connections.
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By following these steps and preparing for the installation process, you’ll be well on your way to successfully installing your tankless water heater.

Step-By-Step Installation Guide

Mounting The Tankless Water Heater

Installing a tankless water heater might seem daunting at first, but with the right guidance, it can be a smooth process. Let’s take a look at the step-by-step installation guide to help you get started:

  • Choose a suitable location for the water heater: Identify a wall where the heater can be mounted securely and close to the water and gas or electrical connections.
  • Ensure proper clearances: Check the manufacturer’s instructions for the recommended clearances around the unit. This will help prevent any potential safety hazards and ensure proper ventilation.
  • Gather the necessary tools: Before starting the installation, make sure you have all the required tools handy, such as a drill, mounting brackets, screws, and a wrench.
  • Install mounting brackets: Use the provided mounting brackets to secure the tankless water heater to the wall. Make sure they are level and securely fastened to provide a stable base for the unit.
  • Hang the water heater: Carefully lift the water heater and hang it on the mounting brackets. Double-check that it is level and well-supported.
  • Connect water supply: Depending on the model, you may need to connect the water supply using either compression fittings or soldering. Follow the manufacturer’s instructions for the appropriate connections.
  • Connect gas or electrical lines: If you have a gas tankless water heater, connect the gas supply line following the specified guidelines. For an electric unit, connect the electrical lines securely, ensuring proper grounding.
  • Test for leaks: Once all the connections have been made, turn on the water supply and check for any leaks. Inspect all joints and connections carefully, and tighten if necessary.
  • Power up the unit: If you have an electric tankless water heater, turn on the power and follow the manufacturer’s instructions to set the desired temperature. For gas units, ensure the gas supply is on and follow the ignition instructions.
  • Flush the system: To remove any debris or air trapped in the system, turn on the hot water and let it run for a few minutes. This will help optimize the performance and longevity of your tankless water heater.

Connecting Water Supply And Gas/Electric Lines

Properly connecting the water supply and gas or electric lines is crucial for the safe and efficient operation of your tankless water heater. Let’s go over the key points to keep in mind:

  • Water supply connections:
  • Shut off the main water supply before connecting the water lines to the tankless water heater.
  • Ensure that you have the necessary fittings and connectors for a secure and leak-free connection.
  • Use teflon tape or thread sealant on threaded connections to prevent leaks.
  • Follow the manufacturer’s instructions for the recommended water pressure range and maximum flow rate for optimal performance.
  • Gas supply connections:
  • If you have a gas tankless water heater, make sure you have a qualified professional handle the gas line installation.
  • Use approved gas piping materials and fittings to avoid potential gas leaks.
  • Apply pipe joint compound or gas-rated teflon tape on threaded connections to ensure a tight seal.
  • Follow local building codes and regulations regarding gas line installation and ventilation requirements.
  • Electric connections:
  • Ensure that the electrical supply meets the specifications provided by the manufacturer.
  • Use the appropriate gauge of wiring and connectors for the electrical connections.
  • Consider installing a dedicated circuit for the tankless water heater to avoid overloading the existing electrical system.
  • If you’re not confident in your electrical skills, it’s best to hire a licensed electrician to handle the electrical connections.

Remember, it’s crucial to follow the manufacturer’s instructions and local building codes during the installation process to ensure a safe and efficient operation of your tankless water heater.

Venting Considerations For Gas Tankless Water Heaters

Proper venting of a gas tankless water heater is essential to ensure the safe removal of combustion gases. Here are a few key points to consider:

  • Ensure adequate clearance: Follow the manufacturer’s guidelines for the required clearance between the vent pipe and any combustible materials. This will help prevent the risk of fire.
  • Use the correct vent type: There are different types of venting systems available, such as direct vent, power vent, and atmospheric vent. Choose the appropriate venting system based on the heater’s location and manufacturer’s instructions.
  • Proper vent sizing: The size of the vent pipe should be determined based on the heater’s btu input and the length of the vent run. Follow the manufacturer’s guidelines to ensure proper sizing and minimize backdrafting.
  • Vent termination: The vent pipe should terminate outside the building, away from any windows, doors, or air intakes. This will prevent the combustion gases from re-entering the living spaces and posing a health hazard.
  • Regular maintenance: Periodically inspect and clean the venting system to remove any debris or obstructions that could hinder proper venting. This will help maintain the heater’s efficiency and prevent potential issues.
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It’s recommended to consult a professional hvac technician or plumber for assistance with the venting installation to ensure compliance with local codes and safety standards.

Ensuring Proper Functionality And Safety

Tankless water heaters are a popular choice among homeowners due to their energy efficiency and endless supply of hot water. If you’re considering installing a tankless water heater, it’s crucial to ensure proper functionality and safety to get the most out of your investment.

In this section, we’ll explore the essential steps you should take to achieve this.

Properly Commissioning The Tankless Water Heater

To make sure your new tankless water heater operates efficiently and effectively, it’s important to properly commission it. Here are the key points to keep in mind:

  • Read the manufacturer’s instructions: Start by thoroughly reading the manufacturer’s instructions to understand the specific requirements and recommendations for your tankless water heater model.
  • Install the unit correctly: Ensure that the installation is done correctly, following the manufacturer’s guidelines. If you’re not confident in your diy skills, it’s always recommended to hire a professional plumber for the installation.
  • Flush the system: Prior to commissioning, flush the system to remove any debris or mineral buildup that may have accumulated during manufacturing or transportation. This step helps to prevent clogs and ensure optimal performance.
  • Adjust the temperature: Set the desired temperature on your tankless water heater based on your household’s needs. It’s crucial to find the right balance to avoid scalding hot water or lukewarm showers.
  • Turn on the unit and test: After completing the installation and adjustments, turn on the tankless water heater and test it by running hot water from multiple faucets. This will help verify if the unit is functioning properly and delivering hot water consistently.

Conducting A Thorough Inspection For Leaks And Performance

While tankless water heaters are known for their durability, it’s still important to conduct a thorough inspection to check for any potential leaks or performance issues. Consider the following points during the inspection:

  • Look for visible leaks: Inspect all connections, pipes, and fittings for any signs of leakage. Address any leaks promptly to prevent water damage and ensure optimal functioning.
  • Check for proper ventilation: Verify that your tankless water heater has adequate ventilation to prevent the accumulation of toxic fumes, such as carbon monoxide. Proper ventilation is crucial for the safety of your household.
  • Monitor water pressure: Ensure that the water pressure is within the recommended range. Excessively high water pressure can strain the tankless water heater and potentially cause damage.
  • Evaluate performance: Test the performance of your tankless water heater by running hot water at different fixtures simultaneously. Check if the unit is able to deliver consistent hot water without fluctuations in temperature.
  • Schedule regular maintenance: Tankless water heaters require periodic maintenance to keep them in top shape. Consider scheduling annual maintenance visits with a professional plumber to ensure ongoing performance and longevity.

By following these steps and conducting a thorough inspection, you can ensure the proper functionality and safety of your tankless water heater. It’s essential to adhere to the manufacturer’s guidelines and seek professional help when needed to optimize your investment and enjoy the benefits of an endless supply of hot water.


Installing a tankless water heater may seem daunting at first, but it’s actually quite manageable. Despite the initial setup and costs involved, the long-term benefits and convenience make it a worthwhile investment. With a little research and preparation, anyone can successfully install a tankless water heater.

By following the manufacturer’s instructions and using the right tools, you can have hot water on demand without the need for a bulky and inefficient tank. Keep in mind the location and size of your unit, and ensure proper ventilation for safety.

Don’t forget to consider your household’s hot water needs when choosing the right capacity. Overall, a tankless water heater offers numerous advantages, such as energy savings, space efficiency, and reliable performance. So, don’t be intimidated by the installation process – with the right approach, a tankless water heater can be a valuable addition to your home.


I am a mechanical engineer and love doing research on different home and outdoor heating options. When I am not working, I love spending time with my family and friends. I also enjoy blogging about my findings and helping others to find the best heating options for their needs.