How to Install an Electric Tankless Water Heater

If you’re looking for a way to save energy and money while still enjoying the comfort of hot water, consider installing an electric tankless water heater. This type of water heater is more energy-efficient than traditional tank models, providing hot water on demand without using up valuable energy or space.

Installing a tankless water heater can be intimidating if you’ve never done it before, but with the right tools and instructions, anyone can do it.

In this guide, we’ll walk you through the steps for how to install an electric tankless water heater so that you can enjoy hot water in no time.

How to Install an Electric Tankless Water Heater

Installation Requirements

Before you start, there are a few requirements and pieces of equipment necessary for a successful installation.

You’ll need a new circuit breaker for the dedicated electrical connection for the tankless unit. You’ll also need hot and cold water outlets, a drain valve, a water pressure regulator, and a flexible hose kit, as well as other components depending on the configuration of your current water heater.

Additionally, you will need to disconnect your conventional water heater and shut off its water supply valves.

Electrical Service Requirements

If you’ve been looking into installing an electric tankless water heater, it’s important to consider the electrical service requirements for your home. Most homes are not suited for a whole-house electric tankless water heater due to the high amp draw that comes with such systems.

For example, the Stiebel Eltron Tempra 36 Plus requires 3 separate dedicated 50A double pole breakers and a recommended main service of at least 300A.

The average home has a total capacity of 200A so this means that you may need to upgrade your old electrical service panel with bigger wires and bigger breakers or run a completely new one which could cost thousands of dollars.

It’s best to consult an electrician before making any decisions on an electric tankless water heater installation.

Water Pressure Requirements

Installation of an electric tankless water heater should take into account the required water pressure. Electric tankless water heaters need 30-150 psi.

To maintain the optimal functioning of the water heater, it is advisable to install a pressure-regulating valve upstream if the water pressure is higher than 150 psi. This will guarantee a consistent temperature and pressure for your hot water requirements.

The pressure-reducing valve also helps protect your tankless unit from potential damage caused by excessive water pressure. It’s also essential to make sure that you choose an electric tankless water heater that meets all of your electrical service requirements and fits your current hot water outlets and pipes.

With everything in place, you’ll be able to enjoy a steady supply of hot water on demand!


When it comes to installing a water heater, most states require that you pull a permit so your work can be inspected for safety. Whether you’re looking to install an electric tankless water heater or replace an old conventional water heater, it’s important to get your local plumbing inspector involved.

So don’t forget: before you start any project that involves water heaters, always remember to pull the necessary permits first!

Tools & Supplies

When it comes to installing your electric tankless water heater, having the right tools and supplies is essential.

You’ll need a circuit breaker to control the flow of electricity, hot water outlets that connect to the electric water heater, a drain valve for draining the tankless unit, electrical connections for connecting the power supply to the water heater, and a flexible hose kit for connecting hot and cold water pipes.

Additionally, you’ll need to check your local electrical service requirements for your specific model of the demand water heater. Finally, don’t forget about all of the required valves and connectors needed to feed in both hot and cooled-off water from the current water heater as well as any additional cold water inlets that may be necessary based on your local water pressure.

With all these tools and supplies in hand, you can rest assured that your electric tankless installation will go off without a hitch!


Having the right tools on hand is essential for any project, and installing an electric tankless water heater is no exception. To complete this job, you’ll need drill and drill bits, flat head and Phillips head screwdrivers, needle nose pliers, an adjustable wrench, and a pipe cutter.

The drill will be used to create holes in the wall for the hot water pipes to pass through. The screwdrivers will help attach various components. The pliers will be used to adjust or tighten wires and screws.

The adjustable wrench will help secure fittings onto the pipes. And finally, the pipe cutter will be used to cut out sections of piping as needed. With all of these tools on hand, you’re ready to install your new electric tankless water heater!


When installing an electric tankless water heater, you’ll need to make sure that you have all the necessary supplies. This includes mounting screws and anchors, piping (like copper or stainless steel flex pipe), shut-off valves, a pressure-reducing valve, a temperature and pressure relief valve (T&P), and Teflon tape. All of these supplies are essential for a successful installation.

Mounting screws and anchors should be provided with your system, but it’s always best to double-check to ensure that you have everything you need. The piping is typically ¾” or ½” in diameter depending on the type of system you purchased. Shut-off valves will help control the flow of water into your system as well as any heated water that may escape from the tankless unit.

The pressure-reducing valve will help regulate incoming water pressure while the temperature and pressure relief valve will protect against dangerous levels of heat or pressure buildup in your tankless unit. Finally, Teflon tape provides a waterproof seal over threaded connections so that nothing escapes through those openings.

Having all of these supplies on hand before beginning your electric tankless water heater installation will save time and energy during what can be an intricate process.

Where to Install

When installing an electric tankless water heater, it’s important to find the right location. For whole-house systems, the most logical place to install the heater is near where hot water is used most often; this will help reduce wait times for hot water. Additionally, make sure you have easy access to the main cold water line.

Point-of-use systems should be installed as close as possible to the point of usage so hot water can be delivered quickly. Electric tankless heaters don’t need venting like conventional models and can typically be mounted directly on any wall with a few simple steps.

Installing a Tankless Water Heater

Installing a tankless water heater is a great way to save money on your energy bill and provide hot water on demand. But before you start, there are some important steps to consider.

1. Turn Off the Circuit Breaker and Water Supply

Before you start any project involving an electric tankless water heater, the first step is to switch off both the circuit breaker and the water supply. This will ensure that the electric cables aren’t powered on while you’re working and that no flooding occurs when you attempt to replace your current water heater with a new one.

Flooding can cause thousands of dollars in damage, so this is a very important step to take. It’s also essential to turn off hot water outlets in order to protect those connected pipes from any damage during installation.

2. Before disconnecting your old heater, make sure to drain it.

Before you begin installing your new electric tankless water heater, it’s important to make sure you drain your old water heater. You’ll need to use a hose and a container, like a bucket, to do this. To ensure your safety and the efficiency of the installation process, you should refer to our guide on how to properly drain a water heater.

Once you’ve completed this step, disconnect the connecting pipes from your old water heater. After that, remove any damaged wiring or wall-mounting brackets before continuing with the installation process.

It’s also important that you pay close attention during this step since any damage done to the pipes will require them to be replaced completely, which will add time and money to the project timeline.

3. Remove the Front Cover

Removing the front cover of your electric tankless water heater is the first step in the installation. Before you start, make sure you have a Phillips screwdriver handy and all the screws in a safe place. Then, take off the front cover by unscrewing each of the screws from the frame.

If there are any wires or cables connected between the cover and the unit, be sure to unplug them carefully before removing them completely. Once all the screws have been removed and put away, you can proceed with installing your new tankless water heater!

4. Mount the Water Heater

Mounting the water heater is an important part of the installation process. The unit needs to be mounted securely and away from any clutter or mess in your home. This will ensure that you have easy access to it in case of an emergency.

To mount the water heater, you’ll need a combination of screws and the mount included in the package. Follow the steps that came with your unit to make sure everything is done correctly.

Once you’ve finished mounting the water heater, you can start connecting it to all necessary electrical connections and water supply lines. Make sure to double-check every connection before turning on the power — safety first!

5. Connect Any Pipes

Once you’ve mounted your tankless water heater, the next step is to connect any pipes that will distribute hot water throughout your home. Look for the inlet and outlet connections on the bottom of the unit and attach your stainless steel pipes to these points.

Be sure to double check any diagrams that you were given with your model, as this can help ensure everything is connected correctly. When it comes to plumbing, it’s always better to be safe than sorry! You don’t want any leaks, so make sure all of your connections are tight and secure before you turn on the water supply.

6. Install Flow and Pressure Valves

Before you can start using your electric tankless water heater, you’ll need to install the flow and pressure valves. Flow valves are simple to install, and they allow you to shut off the water supply to the heater when repairs are needed instead of having to shut off water to your entire home.

Pressure valves only need to be installed if the local plumbing authority requires them, but it’s a good idea to install one on the “hot water” side of the electric water heater for maximum safety.

Make sure that you’re following all instructions carefully and that your connections are tight—otherwise, you could have serious problems with leaks or other damage when turning on your tankless unit.

7. Bleed the Hot Water System

Now that your electric tankless water heater is fully installed, it’s time to perform the bleeding process. This is a simple step that helps get rid of any air in the system and ensures that hot water can flow freely.

First, open all the hot water outlets in your home for a few minutes. This could include faucets, showers, and bathtubs. As you run them, you should see steady streams of hot water coming out of each one. Once this is done, close all the outlets and turn on the main shut-off valve for the hot water system.

The bleeding process should now be complete! Your electric tankless water heater is now ready to provide an endless supply of hot water for your home or business. Enjoy!

8. Inspect Electrical Connections Before Attaching Cover

Before you attach the cover to your electric tankless water heater, it’s important to make sure that all of the electrical connections are properly wired. This is an essential step in ensuring your safety and that of anyone in your household.

Begin by removing the cover from the unit, taking note of where each screw was originally placed. Check all of the terminals to make sure they are connected correctly and wired properly. Once you’ve completed this inspection, reattach the cover and secure it with all of its original screws.

With this final step complete, your electric tankless water heater installation is nearly finished!

9. Switch Circuit Breaker On

Now that you’ve prepared all the necessary elements for installing your electric tankless water heater, it’s time to switch on the circuit breaker. Make sure the circuit breaker is off before proceeding so as not to risk any damage or injury.

To be extra safe, double-check that all electrical outlets and hot water outlets in the space are turned off. Now you can turn the circuit breaker back on. Once it’s switched back on, your tankless unit will start to heat up your water right away!

10. Check Temperature and Test Outlets

Once the unit has been installed, you’ll need to configure the temperature settings so that it’s safe to use and won’t cause any potential burns.

Before using the new system, make sure to test all of your home’s hot water outlets, such as faucets, showers, dishwashers, and clothes washers. This will ensure that the temperature is correct and that the heated water reaches them quickly.

If the water temperature is too high, it can be adjusted by changing the settings. Following these steps will help you quickly benefit from an electric tankless water heater.


Once your electric tankless water heater is installed, you’ll be able to enjoy the benefits of hot water on demand. Make sure to check the temperature settings and test all hot water outlets before using the system.

With a few adjustments, you’ll be able to enjoy consistent hot water whenever you need it. Not only will this save you money on energy costs, but it will also provide you with an unlimited supply of hot water.

With an electric tankless water heater in place, you can have peace of mind knowing that your home has a reliable source of hot water!