GFCI Outlets Explained: A St. Louis Homeowner's Complete Guide
Those outlets with the TEST and RESET buttons aren't just a nuisance—they're one of the most important safety devices in your home. Since their introduction in the 1970s, GFCI (Ground Fault Circuit Interrupter) outlets have prevented countless electrocutions, particularly in kitchens, bathrooms, and outdoor areas.
If you own an older home in the St. Louis area, chances are you're missing GFCI protection in several required locations.
How GFCI Outlets Actually Work
A standard outlet delivers power without monitoring how that power is used. A GFCI constantly compares the current flowing out on the hot wire to the current returning on the neutral wire. These should be equal.
If even a small amount of current (as little as 4-6 milliamps) takes an unintended path—like through water, or worse, through a person—the GFCI detects this "ground fault" and trips instantly.
How fast? About 1/40th of a second (25 milliseconds). That's fast enough to prevent serious injury or death from electrical shock.
For comparison, a standard circuit breaker protects against overloads and short circuits, but it won't trip until 15-20+ amps flow. That's enough current to cause serious harm or death.
Where GFCIs Are Required (2023 NEC)
The National Electrical Code requires GFCI protection in any location where electricity and water might meet. Current requirements include:
Bathrooms - All outlets (this has been required since 1975)
Kitchens - All countertop outlets - Outlets within 6 feet of the sink
Garages & Accessory Buildings - All 125V 15A and 20A outlets (with limited exceptions for dedicated appliance outlets)
Outdoors - All outlets, including covered porches and patios
Basements & Crawl Spaces - All outlets in unfinished areas
Laundry Areas - Outlets within 6 feet of laundry sink
Wet Bar Areas - Outlets within 6 feet of the sink
Pools, Hot Tubs & Fountains - All outlets and underwater lighting circuits
Additional Requirements (Recent Code Cycles) - Sump pumps (2017 NEC) - Dishwashers (2020 NEC) - Electric ranges (2020 NEC) - All kitchen outlets—not just countertops (2023 NEC)
The Problem with Older St. Louis Homes
Many homes in Chesterfield, Kirkwood, Webster Groves, and throughout the St. Louis metro were built before GFCI requirements expanded. We commonly find:
- No GFCI in garages - Required since 1978 but often missed
- Bathrooms with only one GFCI - All outlets need protection
- Outdoor outlets without protection - Major shock hazard
- Basement outlets unprotected - Common in 1970s-80s homes
- Kitchen circuits without GFCI - Only countertop outlets were required until recently
Even homes built in the 1990s and 2000s may be missing GFCI protection that's now required by updated codes.
GFCI Outlets vs. GFCI Breakers
Both provide the same level of protection—the difference is where protection originates:
GFCI Outlet - Protection starts at the outlet - Can protect "downstream" outlets on the same circuit - Easier to test (button right on the outlet) - More visible when tripped - Better for retrofitting existing homes
GFCI Breaker - Installs in the electrical panel - Protects the entire circuit from the panel - No visible buttons on outlets - Better for new construction - More expensive per circuit - Requires panel access to reset
Our recommendation: For most retrofits, GFCI outlets are more practical. For new circuits or whole-circuit protection (like outdoor lighting), GFCI breakers make sense.
Common GFCI Problems and Solutions
GFCI Won't Reset Possible causes: - Ground fault exists somewhere on the circuit - Outlet has failed and needs replacement - Incorrect wiring (line/load reversed) - Moisture in an outdoor box
What to do: If pressing TEST causes it to trip but it won't reset, there's likely an actual fault. Unplug everything on that circuit and try again. If it still won't reset, the outlet itself may be bad.
GFCI Trips Frequently Possible causes: - Moisture in an outlet box (especially outdoors) - Deteriorating appliance insulation - Too many devices creating electrical "noise" - Normal wear—GFCIs do wear out
What to do: Note which appliance was running when it trips. If a specific appliance always causes trips, that appliance may have a fault. If it trips randomly, moisture or outlet failure is likely.
GFCI Won't Trip When Tested This is dangerous. The outlet is no longer providing protection. Replace it immediately.
GFCI is Warm to the Touch A slight warmth is normal (these are active electronic devices). Hot or discolored outlets should be replaced immediately.
How to Test Your GFCIs
Test all GFCI outlets monthly:
- Plug in a lamp or nightlight
- Press the TEST button—the light should turn off
- Press the RESET button—the light should turn on
- If it doesn't trip OR doesn't reset, replace the outlet
Testing takes 30 seconds and could save your life.
GFCI Lifespan
GFCIs don't last forever. Industry estimates suggest:
- 10-15 years typical lifespan
- Surge damage can shorten life significantly
- Frequent tripping may indicate the outlet is degrading
- Outlets that won't reset have failed and need replacement
If your home has original GFCIs from the 1990s or earlier, they should be tested and likely replaced.
GFCI Installation: DIY or Professional?
Why professional installation matters:
- Line vs. Load matters - GFCI outlets have two sets of terminals. Incorrect wiring means no protection for downstream outlets.
- Ground wire required - Self-grounding features require proper box grounding.
- Weather-resistant requirements - Outdoor locations need WR-rated outlets and proper covers.
- Circuit mapping - We identify which outlets should be protected downstream.
- Code compliance - Installation must meet current NEC requirements.
- Testing verification - We verify protection with professional test equipment, not just the button test.
Tamper-Resistant GFCIs
Since 2008, code requires tamper-resistant (TR) outlets in most residential locations. TR outlets have spring-loaded shutters that prevent children from inserting objects into the slots.
When we upgrade GFCIs, we install tamper-resistant versions to bring your home up to current safety standards.
Service Areas
We install and replace GFCI outlets throughout the St. Louis metro including Chesterfield, Ballwin, Wildwood, Creve Coeur, Town and Country, Manchester, Kirkwood, Webster Groves, O'Fallon, St. Peters, St. Charles, Wentzville, Lake St. Louis, and Cottleville.
Protect Your Family
GFCI outlets cost less than a dinner out but can save lives. If your home is missing required protection, or if your existing GFCIs are over 10 years old, schedule a safety inspection and we'll assess your home's GFCI coverage.