Did you know this everyday device should be tested monthly?

Ground-fault circuit interrupters (GFCIs) have been an electrical code requirement in homes for the last 50 years. Depending on the age of your home and renovations, you may or may not have GFCIs.

GFCI closeup
A modern GFCI with a test light, internal self-test functions and tamper-resistant blade slots.

GFCIs are electronic devices designed to shut off power when they detect a common type of electrical shock hazard called a ground-fault. They have substantially reduced the number of accidental electrocutions since they were introduced.

In 1968, the electrical code only required GFCI protected receptacles for swimming pool underwater lighting fixtures. But since 2017 they’re required in all residential bathrooms, garages, outdoor locations, crawl spaces, unfinished portions of basements, kitchens and within six feet of sinks, bathtubs or shower stalls, boathouses and laundry areas.

GFCI outlet sticker
GFCIs can feed through to other standard receptacles like this one to provide shock protection. When wired in this fashion, a sticker is required on the faceplate to alert you to look for an upstream GFCI that may be tripped if no power is available. The “TR” on this receptacle shows it is “tamper resistant” to prevent children from inserting metal objects.

GFCIs are much more sensitive than electrical panel circuit breakers. Circuit breakers are only designed to prevent overheating of the wiring in walls and fires, and don’t provide any shock or electrocution prevention.

GFCI chip
This GFCI shows the electronic “chip” that is used to detect life-threatening electrical hazards and factory-installed surge protection device is visible in the foreground, which helps to protect the GFCI from electrical surges.

If your GFCIs were installed early in their 50-year history, they will lack improvements included in new devices. Older GFCIs are more likely to have gone through more electrical surges, which can cause damage to their sensing components.

If this happens, the receptacle will still allow electricity to flow with no shock or electrocution protection. Older GFCIs can also get worn out from repeated in-and-out plug use, which can cause overheating at the plug blades.

How can you tell if your GFCIs are working properly?

All GFCIs have “test” and “reset” buttons. Follow your manufacturer’s testing instructions. Usually, they are as simple as:

  • Push the test button
  • Listen for a “click” that indicates the unit has tripped and is working correctly
  • Push the “reset” button

That’s all it takes to assure a GFCI is functional and will provide protection from ground-fault related shocks. GFCI circuit-breakers in the electrical panel also have test and reset buttons.

Outdoor GFCIs are more likely to fail because of weather exposure, and the outdoor use of power tools creates an increased risk of cutting cords. It’s best to test an outdoor GFCI before each use to make sure it is working properly.

Outdoor GFCI
This outdoor GFCI will need to be upgraded when it is replaced.

The electrical code updated in 2017 now requires outdoor residential GFCIs to be rated as tamper-resistant (TR) and weather resistant (WR).

The tamper-resistant rating prevents a child from sticking conductive objects into the slots. The weather-resistant rating requires a device that can withstand exposure to cold, water, insects and other exterior contaminants. Older-style covers like in the photo above are no longer acceptable for new installations. New installations must have heavy-duty covers that are closeable and waterproof even when cords are plugged in.

The WR and TR requirements now apply to existing GFCIs in the home that need to be replaced when they become defective. The covers for replacement GFCIs should also be upgraded to the heavy duty style for added physical protection.

Outdoor GFCI receptacle
This is an outdoor receptacle cover that is UL listed for wet locations, identified as “extra duty” and is weatherproof even when the cover is closed with cords plugged in.

When’s the last time you tested your GFCIs?

Take a minute today to test the GFCIs in your home. And remember to do so periodically to help protect you and your loved ones.


© 2018 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. This article is intended for information purposes only. All recommendations are general guidelines and are not intended to be exhaustive or complete, nor are they designed to replace information or instructions from the manufacturer of your equipment. Contact your equipment service representative or manufacturer with specific questions.

John A. Weber

John Weber is principal electrical engineer for HSB. He has over 25 years’ experience in solving facilities and electrical engineering challenges.

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