How to Install an Electric Tankless Water Heater

How to Install an Electric Tankless Water Heater

Hello, savvy homeowners! Today, we dive into the world of electric tankless water heaters — a game-changer in accessing hot water in our homes. Gone are the days of bulky tanks and the dread of running out of hot water mid-shower. Instead, the sleek and compact electric tankless water heater offers an endless supply, heating water on demand and only when needed.

But what does it take to bring this cutting-edge technology into your home? This guide is crafted to demystify the process, turning what might seem daunting into a manageable and rewarding DIY project. Whether you’re a seasoned DIYer or new to home improvement, you’ll find step-by-step instructions, practical tips, and essential insights to confidently embark on this installation journey.

Before we roll up our sleeves, we’ll explore what a tankless water heater is, its benefits, and key considerations to ensure you choose the right unit for your home. Understanding these basics is crucial for a successful installation. We’ll also cover the tools and materials you’ll need so you’re fully prepared when you start.

Installing an electric tankless water heater upgrades your home’s efficiency and contributes to a greener, more sustainable lifestyle. So, let’s begin this exciting project together, ensuring you have all the knowledge and confidence to enhance your home’s comfort and functionality.

What is an Electric Tankless Water Heater?

An electric tankless water heater, often called an on-demand water heater, is an innovative appliance designed to heat water directly without needing a storage tank. When a hot water tap is turned on, cold water travels through a pipe and into the unit where electric elements heat the water.

This process is instantaneous, ensuring that hot water is available when needed. Unlike traditional tank heaters that continuously heat a large reservoir, tankless heaters operate only when hot water is required, making them more energy-efficient.

The benefits of an electric tankless water heater are numerous:

  • Energy Efficiency: By heating water on demand, these heaters are typically more energy-efficient than traditional models, as they eliminate the need to continuously heat a large water tank. This efficiency can lead to significant savings on your electricity bills.
  • Space-Saving Design: Tankless heaters are compact and can be mounted on a wall, freeing up valuable floor space in your home. This makes them ideal for smaller homes or apartments where space is at a premium.
  • Continuous Hot Water Supply: The most significant advantage is the continuous hot water supply. You’ll no longer have to schedule showers or dishwashing around the hot water availability, making your daily routine more convenient.
  • Longevity: Electric tankless water heaters generally have a longer lifespan than traditional tank heaters, often lasting up to 20 years with proper maintenance.

Considerations Before Installation

Before installing an electric tankless water heater, it’s important to consider a few key factors:

  • Electrical System Assessment: Ensure your home’s electrical system can handle the unit’s demands. This might involve upgrading your electrical panel or wiring to accommodate the higher power requirements.
  • Water Demand: Assess the water demand of your household. Consider the number of bathrooms, appliances, and typical usage patterns to determine the right size and capacity of the heater.
  • Right Size Unit: The correct size unit is crucial for efficiency and performance. A unit too small won’t meet your hot water needs, while an overly large one will be less efficient.

Understanding these aspects of electric tankless water heaters will help you make an informed decision and ensure a smooth installation process.

Preparing for Installation

Choosing the right location for your electric tankless water heater is a pivotal step that significantly influences its efficiency and safety. The ideal location strikes a balance between practicality and technical requirements. Firstly, consider proximity to the points where hot water is most frequently used, such as bathrooms or kitchens. Installing the heater close to these areas minimizes the lag time in hot water delivery, ensuring immediate access when you turn on the tap.

Next, ensure that your chosen location has easy access to both power sources and water lines. This proximity is crucial as it simplifies the installation process and reduces the need for extensive modifications to existing electrical and plumbing systems. While electric tankless heaters do not require venting like their gas counterparts, they still need adequate space around the unit to facilitate proper air circulation. This aspect is essential for the safe and efficient operation of the heater.

Finally, consider the ease of maintenance and future inspections when selecting the installation spot. Opt for a location that allows for hassle-free access to the heater. This consideration is vital for routine check-ups and necessary repairs, ensuring that maintaining your tankless water heater is as straightforward as possible.

These considerations in location selection contribute to the optimal functioning of your electric tankless water heater and ensure a smoother installation process and long-term ease of use.

Safety Precautions

Safety should be your top priority during the installation process.

  • Turn Off Main Power Supply: Before starting, ensure that the main power supply to your home is switched off. Use a voltage tester to confirm.
  • Shut Off Water Supply: Similarly, the main water supply should be turned off to prevent any water flow while you’re working.
  • Check Local Codes and Regulations: Familiarize yourself with local building codes and acquire necessary permits. This ensures that your installation is compliant and safe.

By thoroughly preparing and adhering to these safety guidelines, you’re setting the stage for successfully installing your electric tankless water heater.

Tools and Materials Needed

Before installing your electric tankless water heater, gathering all the necessary tools and materials is crucial. This preparation will make the process smoother and ensure safety and efficiency.

Tools and Materials Needed to Install Electric Tankless Water Heater

Tools List:

  1. Adjustable Wrenches: For tightening and loosening pipe fittings.
  2. Screwdrivers: Both flathead and Phillips head for various installation steps.
  3. Power Drill: For mounting the heater to the wall.
  4. Pipe Cutter: If adjustments to existing water pipes are needed.
  5. Pliers: Useful for gripping and tightening components.
  6. Voltage Tester: Ensure safety by confirming the power is off during installation.
  7. Tape Measure: For precise placement and alignment.
  8. Pipe Wrench: Especially if you’re working with galvanized or steel pipes.
  9. Level: To ensure the heater is perfectly horizontal when mounted.


  1. Electric Tankless Water Heater Unit: The main component of this project.
  2. Mounting Hardware: Usually provided with the heater unit.
  3. Proper Gauge Wiring: To safely connect the heater to your home’s electrical system.
  4. Pipe Fittings: For connecting the heater to your water system.
  5. Teflon Tape: To seal pipe threads and prevent leaks.
  6. Safety Equipment: Gloves and safety glasses for personal protection.
  7. Circuit Breaker: Suitable for the electrical demand of the heater.
  8. Valves: Including a pressure relief valve and isolation valves for maintenance.

Step-by-Step Electric Tankless Water Heater Installation Process

Installing an electric tankless water heater can be a rewarding DIY project. Follow these steps carefully to ensure a successful installation:

Step 1: Mounting the Unit

  • Choose the Mounting Location: Refer to the location tips from Section 3. The area should be dry, close to power and water lines, and have enough clearance.
  • Mark the Mounting Points: Hold the heater against the wall and mark the points where the screws will go. Make sure it’s level.
  • Drill the Holes: Use your power drill to make holes at the marked points.
  • Attach Mounting Hardware: Secure the mounting brackets or hardware with your heater to the wall.
  • Mount the Heater: Carefully lift and align it with the mounted hardware. Secure it in place.

Step 2: Connecting Water Lines

  • Prepare the Pipes: If necessary, cut your existing water pipes to accommodate the new heater. Always ensure the pipes are deburred and clean.
  • Connect the Water Inlet and Outlet: Use wrenches to connect the cold water inlet and hot water outlet pipes to your heater. Remember to use Teflon tape on the threads to prevent leaks.
  • Install Isolation Valves: These are crucial for future maintenance and should be installed on the inlet and outlet pipes.

Step 3: Wiring the Heater

  • Prepare the Electrical Connection: Ensure the power is off. Check the required wire gauge and circuit breaker size from the heater’s manual.
  • Connect the Wires: Open the electrical panel on the heater. Connect the wires as directed in the manual. Typically, this will include a ground wire, a neutral wire, and one or two hot wires, depending on your model.
  • Secure the Connections: Once the wires are connected, close the electrical panel on the heater.

Step 4: Initial Setup

  • Turn On the Water Supply: Initially, open the hot water taps in your house to allow air to escape from the pipes.
  • Turn On the Power: Once the air is purged, turn on the circuit breaker to power the heater.
  • Set the Temperature: Access the heater’s control panel to set your desired water temperature.
  • System Check: Check for any leaks around the pipe connections. Also, test the hot water at different faucets to ensure the system works correctly.

Remember, each tankless water heater model might have slightly different requirements, so always refer to the manufacturer’s manual for specific instructions.

Post-Installation Tips

Once your electric tankless water heater is installed, testing the system is crucial to ensure everything is working correctly. Start by turning on a hot water tap in your home and check if the water heats up as expected. Listen for any unusual noises and observe the heater’s operation for any signs of malfunction. If the water isn’t heating properly or you notice any issues, refer to the troubleshooting section of your heater’s manual or contact a professional.

Regular maintenance is key to ensuring the longevity and efficiency of your tankless water heater. Periodically check for any mineral buildup or debris in the filters and clean them as necessary. It’s also wise to flush the system annually to prevent scaling and sediment accumulation, which can impact the heater’s performance. Monitor all connections for potential leaks or wear and address any issues promptly.


Congratulations on successfully installing your electric tankless water heater! This accomplishment enhances your home’s hot water experience and improves energy efficiency and modern living. Enjoy the continuous supply of hot water and the convenience your new system brings. Remember, routine maintenance is essential to keep your water heater functioning at its best. Although the installation process may have initially seemed daunting, the energy savings and improved convenience make it worthwhile. Your proactive approach to home improvement is commendable, and your efforts will pay off in the comfort and efficiency of your home for years to come.