How to Drain an Electric Water Heater

Learn the Proper and Safe Way to Do the Job

By
Bob Formisano
Bob Formisano
Bob Formisano is a licensed architect and builder with nearly 40 years of experience building new homes and restoring older homes. One of his specialties is repairing old systems dating back to the 1920s, including galvanized water pipes, knob-and-tube wiring, and more. His home repair articles for The Spruce span more than 10 years.
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Updated on 07/16/22
Reviewed by
Richard Epstein
Richard Epstein
Reviewed by Richard Epstein
Richard Epstein is a licensed master plumber with over 40 years experience in residential and commercial plumbing. He specializes in estimating as well as design and engineering for plumbing systems, and he works for one of New York's largest union plumbing construction companies.
Learn more about The Spruce's Review Board
Fact checked by
Jessica Wrubel
Jessica Wrubel
Fact checked by Jessica Wrubel
Jessica Wrubel has an accomplished background as a writer and copy editor, working for various publications, newspapers and in public libraries assisting with reference, research and special projects. In addition to her journalism experience, she has been educating on health and wellness topics for over 15 years in and outside of the classroom.
Learn more about The Spruce's Editorial Process
Electric water heater next to blue gloves, red bucket and yellow garden hose for draining

The Spruce / Kevin Norris

Project Overview
  • Working Time: 30 mins
  • Total Time: 5 - 6 hrs
  • Skill Level: Beginner

When you're having problems with an electric water heater and trying to troubleshoot the issue or repair it, you may need to drain the tank. A partial draining can also be preventative maintenance to keep sediment from building up. This is typically recommended every three to six months.

No matter the reason why you need to drain your electric water heater, be sure to follow these steps to do the job properly.

Before You Begin

Before you do anything else, you must first turn off the power to the water heater. This is done at the electrical panel by disabling the circuit breaker or fuse powering the water heater.

Next, turn off the water supply to the water heater. You should find a water shutoff valve at or near the cold water inlet pipe at the top of the tank. Turn the valve clockwise to shut it off. If you cannot find a local shutoff valve, turn off the water supply to the house at the main valve.

What You'll Need

Equipment / Tools

  • Garden hose
  • Flathead screwdriver

Materials

  • Bucket
  • Rubber work gloves

Instructions

Materials and tools to drain an electric water heater

The Spruce / Kevin Norris

  1. Locate and Prepare the Drain

    The drain cock at the bottom of the water heater tank is a silver, brass-colored, or plastic valve with a threaded end. This is where water comes out of the water heater. You need somewhere for the water to go as you drain the tank.

    You can either place a bucket under the drain valve or attach a garden hose to the threaded end of the valve. Run the garden hose to a floor drain if you use that option.

    Yellow garden hose attached to drain cock on electric water heater

    The Spruce / Kevin Norris

  2. Open the Pressure Release Valve

    You will then need to locate the water heater's temperature and pressure (T&P) valve so you can relieve pressure from the tank. It is either on the side or the top of the water heater. Look for a valve that has a tube leading downward.

    Flip the lever on the T&P valve into an up position to open it.

    Pressure release valve opened on electric water heater

    The Spruce / Kevin Norris

  3. Let the Water Cool

    Though you can drain a water heater while the water is hot, best safety practices suggest you would let the water cool down to avoid risks of scalding. You can do this by waiting a few hours.

    Tip

    If the water heater is working well and you're simply draining it for maintenance, now is a good time to take a hot shower. This can help lower the water level in the tank while removing some of the heated water.

    Shower head running water to drain electric water heater

    The Spruce / Kevin Norris

  4. Drain the Tank

    With all safety precautions taken, it is time to drain water from the tank. Some drain valves have a handle. Others have a short handleless stem with a slot for a flathead screwdriver.

    Turn the valve counter-clockwise to release a few gallons of water into the bucket or hose for a partial flush. If you are doing a complete drain and are using a hose, let the tank drain until empty.

    When using a bucket for a full flush, you should use rubber gloves to avoid getting scalded. Fill the bucket and open and close the valve as many times as needed to empty the tank. Make sure to only partially fill the bucket if you need to tip it to get it out from under the valve spout.

    Flathead screwdriver turning valve stem to drain electric water heater

    The Spruce / Kevin Norris

  5. Close the Valve

    Once the draining is complete, close the T&P valve by flipping the lever down and close the drain valve by turning it clockwise. Empty the bucket or remove the hose.

    T&P lever turned downwards to close valve

    The Spruce / Kevin Norris

  6. Restore Power and Water

    With the tank drained, you can perform any maintenance required. When the repair is complete, or if this was just a maintenance flush, turn the power and water supply to the water heater back on.

    Water supply turned on by turning shutoff valve

    The Spruce / Kevin Norris