How To Test GFCI Outlets

GFCIs save lives. Learn how to test your GFCIs two ways, with these instructions.

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Time

A few minutes

Complexity

Beginner

Cost

Less than $15

Introduction

Ground-fault circuit interrupter (GFCI) receptacles — often called GFCI outlets — protect people from electrical shock. GFCIs are required by the National Electric Code (NEC) when the likelihood of electrical shock is greater than usual. Generally, we're talking in bathrooms, kitchens, basements and other places where water could be present.

GFCI protection works by monitoring the current that flows through the receptacle. In a normal scenario, current coming into and leaving the receptacle is equal. Deviation by as little as four to six milliamps (mA) can indicate a dangerous situation called a ground fault. When this happens, the GFCI immediately shuts off power to the receptacle.

The NEC requires GFCI receptacles be listed (i.e. approved) by a laboratory like UL. According to current standards, GFCI receptacles must have an internal monitoring system that checks GFCI effectiveness.

Before 2015, consumers had to physically push the TEST button on the device to know if it still provided protection. Not many people actually do this, so today's GFCI receptacles have a light to alert you if they ever fail the internal testing. They also deny power to the device at the end of its life, indicated by a different colored light.

Even with these safety updates, you should still test your GFCI periodically to ensure the mechanical tripping mechanism works. Models without an indicator light should be tested with a special tester, available at any home improvement center. Post-2015 models can be tested with the TEST button alone. Here's how to do it.

Project step-by-step (5)

Step 1

Option 1: Test GFCI using built-in mechanism

  • Look for two buttons, labeled TEST and RESET, on the face of the GFCI receptacle.

Gfci Test Reset With FingerALLY CHILDRESS FOR FAMILY HANDYMAN

  • Press the TEST button. You should hear an audible click, and the light(s) should go off.
    • Buttons can be hard to push. A wooden chopstick can help. (Do not use metal.)

Gfci Test Push Test Button With ChopstickAlly Childress for Family Handyman

    • If nothing happens, the GFCI requires further investigation or replacement.
  • Press the RESET button to return the GFCI to its usable state. Press hard until you hear a click.
Step 2

Option 2: Test with GFCI tester

Gfci Test TestersAlly Childress for Family Handyman

Step 3

Insert tester into receptacle

  • Plug tester into the receptacle, just as you would plug in an appliance.

Gfci Test Lights On From BelowAlly Childress for Family Handyman

  • Two lights (of three) on the tester should go on, indicating the receptacle is correctly wired.
    • A legend on the tester will tell you what the lights mean.
    • Digital testers may have different indicators. Follow instructions for your individual tester.
  • If the lights don’t come on, remove the tester and press the RESET button on the receptacle.
  • Insert the tester again.

Gfci Test Insert W LightsAlly Childress for Family Handyman

  • If the lights indicating correct wiring still don’t come on or show incorrect wiring, investigate or replace.
Step 4

Test GFCI

  • Press the button on the tester.
  • You should immediately hear a click, and the lights on the tester and receptacle will go off.
  • If nothing happens when you press the button, the GFCI is bad and must be replaced.

Gfci Test Push Button Lights OffAlly Childress for Family Handyman

Step 5

Reset GFCI

  • Reset the GFCI by pressing the RESET button.
  • Press hard until you feel a click.
  • Check that the indicator light(s) came back on.

Gfci Test Light On ChopstickAlly Childress for Family Handyman