How to install an electric water heater - man working on electric panel of water heater

How to Install an Electric Water Heater (10 Steps & Done!)

A do-it-yourselfer with basic electrical and plumbing connection skills can learn how to install an electric water heater — and get it done — in about a day.

That’s not bad for a job that many people would find too daunting to take on. For all our DIY readers who like a moderate challenge, here are the basics for how to install an electric water heater.

How to Install an Electric Water Heater in 10 Steps

The following three sections provide all the basics for replacing and installing an electric water heater.

What You’ll Need


You’ll be working with 240-volt circuits in this job. And that’s a serious matter. We strongly recommend that you remove the fuse or turn off the circuit breaker before getting started.

How to install an electric water heater - danger high voltage sign
A 240-volt circuit has the potential to kill you, though most times it won’t. Don’t take any chances. Keep your hands dry, wear protective gloves, and wear shoes with rubber soles.

Basic Instructions

  1. Shut off water and electric

    Before you do anything else, make sure you shut off the water and power to your old electric water heater.

  2. Test to make sure there is no power

    Remove the access panel to your current electric water heater’s thermostat. It’s usually located behind the lower panel. Push aside any insulation that’s in your way and lift (or remove) the plastic guard. Check for a live current using your neon tester. You want to make sure you have turned off the correct electrical circuit (see step 1 above).

  3. Disconnect and mark wires

    Remove the electrical cover plate at the side or top of the unit. Disconnect the wires and mark them with pieces of tape so you’ll know exactly where to attach them on the new unit. Loosen the screw on the cable clap and carefully pull out the cable.

  4. Drain tank

    Drain the water lines in your home by opening host and cold taps in an upstairs faucet. Also open both taps positioned closest to the systems lowest point. Attach a garden hose to the water heater drain valve. Open the valve and drain the tank.

  5. Disconnect water lines

    Mark hot- and cold-water lines so you won’t hook up the new electric water heater backward. If you have galvanized pipe, open unions near the unit. If you have rigid copper, cut the pipe with a hacksaw or pipe cutter just below the shutoff valves.

    Make the cuts straight so you can tap into the lines easily with new soldered pipe or flexible water lines when you install the new water heater.

    If you have flexible lines, disconnect them. Move the old unit out with an appliance dolly. Do not lift the unit without a dolly or a lot of help from a strong assistant.

  6. Set new unit in place

    Move the new electric water heater into place. Position it to make your connections as easy as possible. Check for plumb and level. Use a shim if necessary. If the unit is in an area prone to dampness, purchase a tray-like base to protect it.

  7. Connect water pipes

    Install water lines. Supply lines can be galvanized steel pipe, rigid copper, or flexible water connectors. Install a ball valve on the supply line. Then install a relieve valve and attach an outlet pipe.

  8. Make electrical connections

    Remove the electrical cover plate on the new water heater. Run the cable through the clamp. Connect the black and white wires with wire connectors and attach the ground wire to the ground screw. Tighten the screw on the clamp to hold the cable in place, gently push the wires inside, and replace the cover plate.

  9. Set thermostat

    Set your new electric water heater to the temperature you want. Press the rest button. Replace the plastic guard, insulation, and access panels.

  10. Turn on water

    Open the water supply valve. Open the nearest hot faucet about halfway and let the system bleed. First, air will come out, then the spattering of water mixed with air. Finally, when the water flows freely, close the faucet.

Learn More About Water Heaters

Here are some great resources for all kinds of water heater information and instructions:


There you have it. Ten steps that take you through how to replace and install an electric water heater in about one day. Maybe less with the help of a strong-backed friend who knows his way around basic electrical and plumbing.

The job is similar to installing a gas water heater with the exceptions that you are making gas connections and there is no flue on an electric water heater.

Call 1-Tom-Plumber

If you need help with the repair, replacement, or installation of a water heater, don’t hesitate to contact us or call us at 1-Tom-Plumber (1-866-758-6237). We will immediately respond to and handle any emergency plumbingdrain cleaning and drain clearing, and water damage problem, including excavation of underground water lines and sewer main lines.

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