How To Install A Tankless Water Heater – Step By Step Guide

Do you want to install an electric tankless water heater in your basement, but you’re clueless about going about doing it? You’ve come to the right place. So stay here and keep reading. You’ll learn how to install a tankless water heater by the end of this article.

Well, before you roll up your sleeves to do this yourself, you must know that installing an electric tankless water heater in your home is not a walk in the park. It requires you to be cautious because even a small error can cause a blackout in your entire home or even set your house ablaze!

However, if DIY is your thing, it would be a breeze. Also in this article, you’ll get step by step guide of connecting a tankless water heater that will make the installation process as easy as possible.

Connecting A Tankless Water Heater

Tools/Equipment You’ll Need For Tankless Water Heater Installation

Below are the tankless water heater installation requirements i.e. you’d need the following tools to fix your water heater:

  • Pipe cutter
  • Pliers
  • A drill and drill bits
  • An adjustable wrench
  • Phillips screwdriver
  • Flathead screwdriver
  • A shut off valve
  • A temperature and pressure valve
  • Anchors and mounting screws for the new heater
  • Stainless or copper steel flex pipe
  • Sealing tape
  • Double pole circuit breakers
  • Pipe insulation
  • Grounding wire
Tools/Equipment For Tankless Water Heater Installation

Tankless Water Heater Installation Instructions

Step 1: Read Thoroughly the Product Manual

Read The Product Manual

Before starting the tankless water heater installation process, ensure that you go through the product manual. Refer to the tankless water heater installation diagram carefully. Some manufacturers may void the warranty if a licensed contractor doesn’t fix the unit.

Step 2: Confirm Your Electrical Service Panel

Confirm Your Electrical Service Panel

A water heater to supply sufficient hot water in your basement would require a minimum of four 40AMP. So, ensure that you confirm whether your electrical service panel will handle the energy that your tankless water heater would operate.

You can check the label at the electrical breaker or the electrical panel or enquire from an electrician. If it’s unable to handle it, you’ll have to upgrade your panel.

Step 3: Check if you’ve Enough Water Pressure

Check Water Pressure

Primarily electric tankless water heaters work well in pressure between 30psi-150psi. Therefore, it is important to confirm if your water has the right pressure.

If the pressure is higher than 150psi, you’ll have to fix a pressure-reducing valve on the tankless water heater when installing the hot and cold water connections.

Step 4: Pull Permit

Pull Permit

Are you aware that for you to install a water heater in your basement, In some countries you’d require a permit from the State Department of Building? Yes, you’ve to get it inspected by your state’s department official before you begin your project.

Step 5: Look for a Perfect Spot

For the hot water to be sufficiently supplied in the whole home, you’ll have to install the unit closer to where the hot water is mainly used. Place it vertically with power and water supply connections facing down.

Also, avoid areas where:

  • There is a lot of moisture.
  • The unit can be affected by the freezing temps.
  • Any liquid would regularly splash on the unit.

Step 6: Turn the Circuit Breakers and the Water Supply off

Turn Off The Circuit Breakers And Water Supply

For any circuit breakers related to the unit, turn them off before starting the project to prevent you from being electrocuted while you’re working.

Also, turn off your main water supply to prevent your workplace from flooding. Although it might look obvious, note that many homes have lost a lot of properties from water damage after forgetting to turn off the main water supply.

Step 7: Disconnect the Old Heater

If you want to disconnect the old heater:

  • Turn the water supply off that serves the unit.
  • For any gas and power supply feeding the heater, shut it off and drain the unit by opening the faucet of the hot water to release the pressure in the unit.
  • Then, disconnect the water heater from the water and the gas lines and dispose it properly.

If you want to know step-by-step instructions on how to replace a tankless water heater, Check out the following online video by electronicsNmore

How To Replace A Water Heater With A Tankless Water Heater(STEP BY STEP)

Step 8: Take the Cover off

Before fixing the new heater, carefully remove the front cover using a suitable screwdriver to remove all screws securing it. Place the screws in an ideal place where you won’t lose them, as every screw is essential for the effective functioning of the water heater.

If your water heater has an LCD screen, you need to remove the cover carefully as some cables might be linked to the main unit. Cautiously unplug the wires to avoid breaking them. Now, the next step is tankless water heater mounting.

Step 9: Mount the Water Heater

Mount The Water Heater

Following the instruction manual, mount the heater on the wall. Ensure that it isn’t positioned in a messy or cluttered area of your basement. Doing this will ensure easy access in case of an emergency.

This process is pretty simple, particularly if you’re a DIY type. With simple screws, the manual, and the supplied anchors, you’re ready to go.

Step 10: Connect the Pipes

Connect The Pipes

Once you’ve mounted the device, connect the cold and hot water pipes to run in and out of the water heater. And since most electric tankless water heaters have only one way, check at the unit’s bottom to connect the pipes; however, if you have the installation diagram, refer it. It would be best if you also refer to the tankless water heater plumbing diagram given in the product guide.

Using stainless steel flex pipes that fit the water heater would go a long way to accommodate the high temperatures.

However, you can go for copper or PVC pipes if you can’t access the stainless steel pipes. But, you’ve to check on the quality of your work and the smoothness of the edges. Doing so would prevent any thread damage, especially if you’ve opted for the copper or PVC pipes.

Step 11: Install Pressure and Flow Valve

Install Pressure And Flow Valve

After connecting the pipes, install the pressure and the flow valve. The flow valve is installed after and before the heater to allow you to turn off the tank’s water supply during maintenance without interfering with your household water supply.

On the other hand pressure valve is installed along the “hot water” on electric water heater’s side. You should also install another one on the heater’s other side for maximum safety. Pressure valves are only installed when the local plumbing authority requires them.

Step 12: Purge Air and Check for Leaks

Check For Leaks

Once you’ve fully installed and connected the water heater, remove any air in the unit and the pipes before turning it on. Wondering how? Okay, open all the hot water outlets and leave them for a few minutes.

As you continue waiting for the air in the tankless water heater to be purged, check for any leak in each connection. 

Step 13: Check the Electrical Connections and Re-attach the Cover

Check The Electrical Connections

While connecting the electricity with the heater, ensure that the electrical panel is on one side and the heater is on the other side. Then follow the manufacturer’s diagram and directions to choose the correct wire and circuit breaker size.

Push the wires through the bottom holes of the tankless water heater housing. Then insert the cables in their slots on the terminal block.

Confirm whether your electrical connections are correctly wired and are in the correct terminal, and then re-attach the cover using the screws you had earlier removed. Check all of the tankless water heater connections as well.

Step 14: Turn the Circuit Breakers on

Turn On The Circuit Breakers

Since you’d not work again on the heater, switch the circuit breakers on and choose your ideal unit settings.

Step 15: Check the Water Temperature

Check Water Temperature

Turn the faucet’s hot side in your home on and check the water temperature once it has stabilized. Then, if you wish, you can adjust the unit’s temperature and, finally, test every hot water outlet to check if the water temperature is appropriate.

With all that done, you can now pat yourself on the back as you’ve successfully installed your electric water heater securely and safely.

Hopefully, now you know how to connect a tankless water heater and how to plumb a tankless water heater. So start working on your DIY project. Don’t forget to tell us about your experience in the below comment box.

If you find this tankless water heater installation guide useful, you should also refer to the following –

Step by Step Guide of Installing a Pedestal Sink in Your House!
Step By Step Guide on How To Install Sink Pop-Up Drain Stopper
DIY Toilet Flange Installation | Step-by-Step Instructions for You!

Author Bio

Jennifer Kiminza – Jennifer Kiminza is a content writer and content marketing professional at Hub Spot, an inbound marketing and sales platform that helps companies attract visitors, convert leads, and close customers. Previously, Jennifer worked as a marketing manager for a tech software startup. She graduated with honors from Nairobi University with a dual degree in Business Administration and Creative Writing.

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