Ground Fault Circuit Interrupter – GFCI

ground-fault circuit interrupter

A ground-fault circuit interrupter, or GFCI for short, also sometimes abbreviated to just GFI, is a safety device that cuts power to an outlet in approximately 1/40th of a second if it senses a fault in the ground. The most common source of a ground fault is water, making GFCI an important method to protect people from electrical shock around water.

The most common method of ground fault protection is the GFCI Receptacle, better known as the outlet with the little buttons. The other allowed, but the less common method is a GFCI breaker at an electrical panel.

GFCI Outlet
GFCI Outlet

GFCI protected outlets are required in areas of the home that are near or potentially near water.  The easiest way of protecting an outlet is by installing a GFCI receptacle (with the little buttons) at each outlet. However, it is also legal to wires several outlets to be tied to one outlet with the button, which is commonly referred to as being wired in series. For example, many Santa Clarita homes, all the bathrooms are tied together so that the reset button in one bathroom controls all the outlets in all the other bathrooms. Which means yes, if you trip the outlet in the master bathroom, you may have to walk downstairs to the half bathroom to push the reset button.

Occasionaly the outlets reset at the breaker in the panel. This is also considered legal.

GFCI Breaker
GFCI Breaker

GFCI protection was first introduced into building codes in the early 1970’s by the National Electric Code (NEC). Every 3 to 4 years, the NEC codebook is modified, and the codes for GFCI’s then often get modified as well. And then when the NEC makes a change, it usually takes another 3 to 4 years before local building codes adopt the changes. Hence very few homes have GFCI protection in every place required by the most modern codes. However, just because it was not code when a home was built, we still highly recommend outlets be upgraded to GFCI protection in wet or damp areas.

Let’s look at where GFCI protection is required:


GFCI protection was introduced as a concept for outlets near swimming pools and pool lights in 1971, and then all exterior outlets in 1973. Because most people don’t remodel their outside, the exterior is the most common area for people to forget to upgrade their outlets to GFCI protection.


GFCI protection in bathrooms was introduced in 1975. All outlets in a bathroom should have GFCI protection.


The requirements for GFCI protection in a garage was introduced in 1978. Some find it odd if there is no source of water, but the assumption is your car, after driving in the rain, will be parked in the garage, which then brings water into the garage. This is also the most common place we find GFCI protection missing. One issue with inspecting for GFCI protecting in garages is the reset switches often get hidden behind boxes, storage shelves, and extra refrigerators.


GFCI’s were first recommended in a kitchen in 1987, but at first only within 3 feet of the kitchen sink. Later, within 6 feet of a kitchen sink. Then in the early 2000s, it was realized everywhere along the kitchen counter should have GFCI. One exception is a refrigerator does NOT have to be plugged into a GFCI.

Then in 2017, the concept of haing the dishwasher have GFCI protection was inotroduved. Though oddly, there is no current requirement for a garbage disposal to have GFCI protection.

Basements and Crawlspaces

We have very few basements here in Southern California, and we rarely see an outlet installed in a crawlspace. But if there is an outlet to be found under the house, it s should have GFCI protect, as that was introduced in 1990.

Wet Bars and other sinks

Given outlets neat bathroom and kitchen sinks already required to be GFCI protected, it’s odd that outlets near Wet Bar sinks were technically not required to be until the early 1990’s.

Laundry Rooms

Outlets near a laundry room sink are an obvious requirement But more recently, people began to realize that, hey a washing machine is also a source of water, which is plugged into a wall, shouldn’t that also have GFCI protection? And now the answer is yes, washing machines should be plugged into outlets with ground fault protection. As this is such a relatively new code, it’s rare to actually see, but it is still a recommended upgrade.

Testing a GFCI outlet
Testing a GFCI outlet

Final Thoughts

Upgrading an outlet to GFCI protection is a relatively simple and common job for a qualified electrician. We recommend ONLY a qualified electriian installs or modifies any electricial component in a house.

Existing GFCIs should be periodically tested, as the buttons can and will go bad from time to time.

The common question – is it required for a homeowner to upgrade to GFCI protection if it was not required at the time of construction? And the answer is no, it’s only required when the room is remodeled. However, for safety reasons, it is always recommended all wet and potentially wet areas be upgraded to GFCI as soon as possible.

To book your home inspection, call 818-298-3405