How to Test GFCI Outlets

Ground Fault Circuit Interrupters (GFCIs) are a critical part of any home’s electrical safety system. Installed in areas where water and electricity may come into contact, like bathrooms, kitchens, garages, and outdoors, GFCIs detect dangerous current leaks and quickly shut off power to prevent serious electric shocks or electrocutions.

Testing your GFCIs regularly is essential to ensure they are functioning properly and able to provide maximum protection. Faulty GFCIs that fail to trip can allow lethal shocks to occur. We’ll cover the easy process below so you can inspect all your outlet’s operation.

What is a GFCI Outlet?

A GFCI monitor’s electricity flowing through a circuit. If there is an imbalance, like current leaking through water to the ground, it will instantly “trip” or switch off power.

This break in the flow of electricity minimizes the risk of electrocution. GFCIs may be installed at the breaker box protecting downstream outlets or as a standalone outlet.

Why Test GFCIs?

To Verify Functionality: GFCIs contain an internal sensing mechanism that can weaken over time. Testing ensures this protection device will trip when needed.

For Early Detection of Problems: Faulty GFCIs may fail to stop power flow during a ground fault. Regular testing finds issues to allow repairs.

For Peace of Mind: Frequent inspections give homeowners confidence in the safety of their electrical system. Knowing GFCIs work reassures the devices offer critical protection.

It’s Required: Manufacturers recommend testing GFCIs every 3 months. The National Electric Code (NEC) also mandates testing after installation and before use.

How Often to Test GFCI Outlets

  • Monthly: Test all GFCIs once a month. This frequent inspection ensures outlets are working properly. It takes just seconds to verify an outlet.
  • After Installation: New GFCI outlets should be tested as soon as they are installed or wired. This initial test makes sure the device functions before use.
  • After Repairs: Anytime electrical work is done, GFCIs should be tested before turning power back on. Tripping the outlet will confirm correct wiring.
  • Before Use: Test GFCIs prior to using outlets in isolated locations, like at the lake cabin or vacation home, to ensure safety.
  • After Power Outages: Electrical surges from storms can damage GFCIs. Test all outlets following an outage before using.
  • When Relocating: If moving an outlet, test it before plugging anything in to check for wiring errors during the move.
  • After Major Appliance Repairs: Faulty appliances can overload and damage GFCIs. Test outlets after any appliance installation or repair.

Regular testing at least every 30 days provides inexpensive reassurance your GFCIs offer maximum protection. Mark your calendar to remind you each month.

How to Test a GFCI Outlet

Testing a GFCI outlet is simple and only takes a few seconds. We’ll review the step-by-step process:

What You Need

  • GFCI outlet
  • GFCI testing device (optional)

Step 1: Reset the GFCI

Begin by resetting the outlet if it has been tripped.

  • For outlet GFCIs, ensure the “Reset” button is pushed in. The reset button is usually distinguished by its color and text labeling.
  • For GFCIs located at the breaker box, flip the switch to the “On” position.

Step 2: Plug in the GFCI Testing Device (Optional)

A GFCI tester is a useful tool that will trip the outlet when the test button is pushed. This gadget allows a single person to easily test the function.

Plug the tester directly into the outlet, ensuring full contact. Follow the device directions for performing the test.

Step 3: Trip the GFCI

To trip the GFCI without a tester, you will need to initiate a ground fault to trigger the safety mechanism.

  • For outlet GFCIs, push the “Test” button. This should immediately trip the outlet. The “Reset” button will pop out.
  • For breaker GFCIs, push the “Test” button to trip the circuit. Flip the breaker to “Off” then back to “On” to reset it.

Note: Only use the “Test” buttons to trip GFCIs. Never intentionally create a ground fault by inserting a cut plug or exposed wire into the outlet which could be dangerous. The test button safely simulates a ground fault electronically.

Step 4: Reset the Outlet

Once tripped by the test, reset the GFCI:

  • For outlet GFCIs push the “Reset” button back in until it catches and remains depressed.
  • For breaker GFCIs, flip the switch to “Off” then back to “On”.

If the outlet resets properly, then the test is complete! However, if the GFCI trips as soon as power is restored, this likely indicates a faulty device in need of replacement.

Step 5: Verify Indicator Lights

Modern GFCI outlets include indicator lights that should activate during testing:

  • A “Power On” light confirms power to the outlet. It will go off when tripped.
  • A “Ground Fault” indicator should turn on when tripped, signaling the internal sensing circuit worked properly.

Check that both indicators function as expected during testing. If not, replacement of the faulty GFCI is needed.

What to Do if the GFCI Won’t Trip

A GFCI that fails to trip during testing is defective and no longer supplying protection from serious shocks. If pushing the test button has no effect, try the following steps:

  • Confirm the outlet is getting power by plugging in a tester or lamp. If there’s no power, check the breaker supplying the circuit.
  • For outlet GFCIs, bypass any surge protectors, power strips, or extension cords. Plug the tester directly into the outlet.
  • Try resetting then testing again. Loose wiring can sometimes cause intermittent tripping failures.
  • Test another nearby outlet protected by the same GFCI. If this trips, the issue is probably wiring related and not the GFCI itself. Call an electrician.
  • Check for frequently tripped GFCIs. Excessive tripping indicates a ground fault from another appliance or damaged wiring. Try isolating items on the circuit to identify the cause.
  • If other outlets trip but the faulty one does not, replace just that outlet right away. Never use an outlet that fails the test.

Malfunctioning GFCIs should be replaced by a qualified electrician as soon as possible for safety. Only use replacement outlets that are exactly the same model to avoid compatibility issues.

What to Do if the GFCI Won’t Reset

If a GFCI trips when testing but refuses to reset, this typically signals a wiring problem. Possible causes include:

  • Faulty wiring of the outlet itself or somewhere in the branch circuit. This can make it unable to reset once tripped.
  • A grounded or shorted conductor providing voltage on the load terminals. This permanently trips the outlet when the power returns.
  • Too many outlets or lights on one circuit overwhelming the GFCI when power is restored.
  • Incompatible GFCI models mixed on the same circuit. Some types won’t reset if different brands are combined.

A faulty or incompatible GFCI that won’t reset after tripping will require investigation and repair by an electrician. Leaving tripped outlets can result in disrupted power and resetting problems.

Special Considerations for GFCI Testing

Keep these safety tips and warnings in mind when testing GFCIs:

  • Never push a GFCI’s test and reset buttons randomly without checking the outlet first. Only test after confirming it’s currently powered on and set in “reset” mode.
  • Outlets protected by a tripped GFCI will be dead. Remember to warn others of lost power during testing.
  • Never test GFCIs during bad weather. Lightning strikes can destroy outlets.
  • Faulty GFCI testing could blow a fuse or breaker. Locate the upstream protection device before testing in case you need to quickly reset it.
  • Only use the supplied test and reset buttons to trip. Never intentionally generate a real ground fault which could be hazardous.
  • Negative results on your first GFCI test are common. Try resetting carefully before assuming it’s completely failed.
  • Be gentle when pushing small test buttons. Excessive force can break the internal switch contacts.
  • Stand clear of outlets when testing and keep fingers away from sockets and buttons. Serious arcs can occur on malfunctioning GFCIs.

Testing GFCIs is a straightforward process. By inspecting them regularly yourself, you can identify any units in need of replacement and ensure uninterrupted protection. Consult an electrician regarding any outlets that fail testing to correct improper wiring or replace faulty GFCIs.

Frequently Asked Questions About Testing GFCI Outlets

1. Why does my new GFCI trip constantly for no reason?

Frequent, unexplained tripping of a new GFCI outlet often indicates improper wiring. The most common mistakes are reversed hot and neutral wires or grounding to the neutral terminal. An electrician should examine the installation method and wiring connections.

2. Do I need to turn off the power before testing GFCIs?

No, you do not need to turn off the circuit breaker before testing. The test button electronically simulates a ground fault without interrupting power. Just make sure to only push the test and reset buttons.

3. Can I just replace an old outlet with a GFCI without rewiring?

In most cases, you cannot directly replace an old 2-prong ungrounded outlet with a GFCI. The GFCI needs a ground wire to function which requires new 3-conductor wiring. Consult an electrician on code-compliant installation.

4. Why does the reset button on my GFCI pop back out when I push it in?

If the reset button pops back out when trying to reset the outlet, this usually means the GFCI has detected another ground fault and is tripping again. Try unplugging appliances on the circuit one at a time to isolate the cause.

5. Do I need GFCIs if I already have circuit breakers?

Yes, GFCIs provide protection that circuit breakers cannot. Breakers only trip due to overloads not ground faults. GFCIs detect leakage currents and cut power in as little as 0.025 seconds to prevent electrocution.

6. Can GFCI outlets protected by a GFCI breaker still be tested?

Yes, the GFCI outlets will trip as usual when testing even if they are also protected by an upstream GFCI breaker. Test each regularly to confirm they detect ground faults since the breaker won’t necessarily trip.

Regularly testing GFCI outlets is a fast and easy way to confirm they function properly, ensuring safe protection for your home. Reach out to a qualified electrician for installation and troubleshooting issues.


Testing GFCIs takes just seconds but provides invaluable protection by detecting faulty outlets that cannot offer protection from lethal shocks. This simple monthly tasksafeguards your home from electrical dangers. Follow the easy steps outlined to inspect all GFCIs and correct any issues, giving you peace of mind that your electrical system is sound. With a safe, well-functioning set of GFCI outlets throughout your home, you can confidently use electricity without unnecessary risk to your household.