Electric Tankless Water Heater Installation | Expansion Tank Placement Guide

Did you know that traditional water heaters account for about 18% of your home’s energy usage? By switching to an electric tankless water heater, you can save both energy and money. Not only does the installation of a tankless hot water heater by a professional plumber reduce standby energy losses, but it also provides on-demand hot water for efficient operation whenever you need it. Incorporating a water heater expansion tank, boiler, and type tanks during the installation process by a professional plumber ensures optimal performance and longevity for your system with fittings. Say goodbye to wasted energy and hello to endless hot showers with a seamless electric tankless water heater installation.

Importance of Expansion Tank Placement

Water Heater

An expansion tank’s placement in a water heater system is crucial for preventing water hammer issues. Incorrect positioning can lead to noisy pipes and potential damage.

Placing the expansion tank near the water heater allows it to absorb excess pressure caused by thermal expansion, safeguarding the plumbing system.

Improper placement can result in reduced efficiency of the overall system, affecting its performance and potentially leading to frequent repairs.


Proper installation of the expansion tank is essential for maintaining stable water pressure throughout the system. It should be positioned correctly to ensure optimal functionality.

During the installation process, ensure safety by mounting the expansion tank vertically above the water heater on the cold-water supply line. This setup allows proper absorption of expanded water volume.

Incorrect installation, such as placing the expansion tank in a horizontal position or at a distance from the water heater, can diminish its effectiveness.


Regular maintenance of the expansion tank is necessary to guarantee its continued efficiency. Checking for leaks in water pipes and ensuring proper pressure levels are vital steps in maintenance routines.

A well-maintained expansion tank contributes to stable water pressure, prevents damage to pipes, and extends the lifespan of the entire system.

Neglecting maintenance tasks can lead to fluctuations in water pressure, increased energy consumption, and potential risks of leaks or burst pipes.

Preparing for Electric Tankless Heater Installation

Gathering Materials

Before beginning the tankless water heater installation, ensure you have all the necessary tools and materials. This includes pipes, fittings, valves, and mounting hardware.

Make sure to have a pipe cutter, wrenches, screwdrivers, and a level on hand. Gather Teflon tape, pipe sealant, and a voltage tester for electrical safety checks.

Checking Electrical Requirements

To ensure a smooth electric tankless water heater installation process, check the electrical requirements. Verify that your home’s electrical system can support the heater’s power needs.

Ensure compatibility with the existing setup by checking voltage requirements and amperage ratings. If needed, consult an electrician to ensure any necessary upgrades or adjustments, including the hot water heater and expansion tank.

Clearing Installation Area

Prepare the area where the hot water heater will be installed by clearing out any clutter or obstacles. Ensure there is ample space for the unit, expansion tank, and hot water heater, and easy access to plumbing and electrical connections.

Clean the installation area thoroughly, including the tank, to prevent dust or debris from affecting the water heater performance. Consider installing a drip pan underneath the hot water heater tank for potential leaks or condensation.

Ensuring Proper Placement

When preparing for tankless hot water heater installation, consider the location carefully. Choose a spot close to the main hot water pipe to minimize heat loss and maximize efficiency.

Ensure there is proper ventilation around the unit, especially the hot water heater tank, to prevent overheating. Avoid placing the heater near combustible materials or in confined spaces without adequate airflow.

Securing Gas Lines

If you are installing a gas-powered demand water heater, ensure that gas lines are properly connected and secured. Check for leaks by applying a soapy water solution to all connections while the gas is turned off.

Follow manufacturer instructions for connecting gas lines safely and securely. Consider hiring a professional plumber if you are not experienced in working with gas lines.

Step-by-Step Electric Tankless Heater Setup


Securely mount the tankless water heater on the wall or a suitable surface using appropriate brackets. Ensure it is level.

Pipe Connection

Connect the inlet and outlet pipes to the unit following the manufacturer’s guidelines carefully. Use proper fittings for a leak-free connection.

Temperature Adjustment and Testing

Adjust the temperature settings on the heater according to your preferences. Test the unit by turning on the water supply to ensure it functions correctly.

Safely Establishing Electrical Connections

Turning Off

Before proceeding with electric tankless water heater installation, it is crucial to prioritize safety. Begin by turning off the power supply to the area where you will be working. This step is fundamental in preventing any electrical accidents or mishaps during the installation process.

Following Safety Procedures

When establishing electrical connections for your tankless hot water heater, always adhere to proper safety procedures. Ensure that you are using the appropriate materials and following the guidelines set by your local codes. By doing so, you significantly reduce the risk of electrical hazards.

Connecting Wires

Refer to the electrical diagram provided by the manufacturer for your water heater expansion tank installation. This diagram serves as a guide for connecting the wires correctly. Make sure to match each wire according to the diagram to avoid any errors in the connection process.

Double-Checking Connections

After connecting the wires, it is essential to double-check all electrical connections thoroughly. Verify that each connection is secure and properly installed. This step is critical in ensuring that your electric tankless water heater functions efficiently and safely.

Advantages of Going Tankless

Endless Hot Water Supply

Tankless water heaters provide endless hot water supply by heating water on demand, eliminating the need for a storage tank. With this technology, you can enjoy long showers or fill up your bathtub without running out of hot water heater.

Energy Efficiency and Cost Savings

Saving energy is a significant advantage of tankless water heaters. They only heat water when needed, reducing standby heat loss common in traditional tank-type heaters. This efficiency not only benefits the environment but also leads to substantial reduction in utility bills over time.

Space-Saving Design and Longer Lifespan

One key benefit of tankless water heaters is their space-saving design. Unlike traditional tanks that take up considerable space, tankless water heater units are compact and can be mounted on walls, saving valuable floor space. These units have a longer lifespan compared to traditional water heaters, providing reliable hot water for many years.

Efficiency and Lifespan of Tankless Heaters

Energy Efficiency

Tankless heaters are renowned for their energy efficiency, offering significant long-term savings. These units only heat water when needed, eliminating standby energy losses common in traditional tank water heaters.

Moreover, tankless heaters boast impressive energy efficiency ratings, often exceeding 90%. This means that a minimal amount of energy is wasted during the heating process, translating to lower utility bills for homeowners.

Extended Lifespan

One key factor contributing to the extended lifespan of tankless heaters is their design. Unlike traditional tank water heaters that store and heat water continuously, tankless models operate on-demand, reducing wear and tear on components.

The absence of a storage tank in tankless heaters eliminates issues such as corrosion and leaks that commonly plague conventional water heaters. This results in a longer operational lifespan for tankless units.

Maintenance Comparison

When it comes to maintenance requirements, tankless heaters have a clear advantage over conventional systems. Traditional tank water heaters require regular flushing to remove sediment buildup, which can affect performance and efficiency.

On the other hand, tankless heaters typically have lower maintenance needs. While periodic descaling may be necessary in areas with hard water to prevent mineral deposits, overall maintenance is minimal compared to traditional water heaters.

Ensuring Reliable Operation and Easy Repairs

Regular Maintenance

Regularly flushing the tankless water heater is crucial to prevent mineral buildup and ensure efficient operation. This maintenance task helps maintain the optimal performance of the appliance over time.

Flushing the system involves removing sediments, which can accumulate and hinder the heater’s ability to function effectively. By performing this simple task, homeowners can extend the lifespan of their water heater and avoid potential issues down the line.

Troubleshooting Tips

When it comes to troubleshooting, being aware of common issues such as fluctuating water temperature or error codes is essential. Understanding how to address these problems can help ensure that the tankless water heater operates smoothly.

For instance, if you encounter a problem with the water temperature or heater, checking the unit’s settings and ensuring proper ventilation can often resolve the issue. Similarly, familiarizing yourself with common error codes can expedite the process of identifying and addressing any malfunctions.

Professional Assistance

While some maintenance tasks can be handled through DIY efforts, there are instances where seeking professional help is necessary. For complex repairs or issues beyond your expertise, contacting a qualified technician is paramount to ensuring the longevity of your tankless water heater.

Professional technicians have the tools and expertise to diagnose and address more intricate problems such as malfunctioning pilot lights or control panel issues. They can conduct thorough inspections to identify underlying issues that may compromise the appliance’s functionality.

Installation Considerations and Flow Rate

Sizing Requirements

To ensure efficient installation, calculate the required flow rate based on hot water usage in your household. This helps in sizing the tankless unit appropriately for optimal performance.

When considering installation locations, prioritize areas closer to the primary water usage points and heater to minimize heat loss. This strategic placement helps optimize hot water delivery efficiency throughout your home.

Water Temperature Impact

The incoming water temperature significantly affects a tankless water heater’s performance. Lower temperatures require more energy to heat, impacting the unit’s overall efficiency and effectiveness.

Properly assess water pressure within your home’s water distribution system. Inadequate pressure can lead to issues with the heater’s operation, affecting its ability to provide consistent hot water flow.

Consider the impact of gas flow in relation to the tankless water heater unit’s requirements. Ensuring sufficient gas flow is crucial for the heater to function effectively and meet your household’s hot water needs.


You’ve now grasped the crucial steps for installing an electric tankless water heater. Understanding expansion tank placement, preparation, setup, electrical connections, advantages of going tankless, efficiency, lifespan, reliable operation, and installation considerations are key. By following these guidelines diligently, you ensure a seamless and efficient installation process that guarantees long-term benefits and savings. Remember to prioritize safety, efficiency, and reliability throughout the installation to enjoy continuous hot water supply without any hitches.

Upgrade your home with an electric tankless water heater today to experience endless hot water and energy savings. Your commitment to a well-executed installation will pay off in the form of lower energy bills and a reliable hot water supply. Take action now for a more sustainable and convenient lifestyle.

Frequently Asked Questions

How important is the placement of an expansion tank in a water heater system?

Placing the expansion tank correctly is crucial to prevent damage caused by thermal expansion. It helps regulate pressure changes, ensuring your water heater operates efficiently and extends its lifespan.

What are the key steps to prepare for installing an electric tankless water heater?

Before installation, ensure you have proper electrical connections, adequate space, and necessary permits. Consider factors like water flow rate and temperature needs to select the right unit for your home.

Can you outline the process of setting up an electric tankless water heater step-by-step?

The setup involves mounting the unit, connecting water lines, installing venting if required, and adjusting settings. Follow manufacturer instructions carefully for a safe and efficient installation process.

How can one safely establish electrical connections when installing a tankless hot water heater?

Ensure all power sources are turned off before working on electrical connections. Follow local building codes and manufacturer guidelines precisely to prevent hazards and ensure a secure electrical setup.

What are the advantages of switching to a tankless hot water heater system?

Tankless heaters offer benefits such as energy efficiency, endless hot water supply, space-saving design, longer lifespan, and reduced utility bills. Enjoy consistent hot water on demand without worrying about standby heat loss.


“Expert guide on electric tankless water heater installation & expansion tank placement. Ensure proper installation for your hot water system.”