A GFCI outlet trips when it detects even a tiny imbalance in electrical current, often from moisture, an aging appliance, or a wiring issue. Press the 'Reset' button firmly to restore power; if it won't reset, or trips again right away with nothing plugged in, unplug everything downstream and call an electrician.
How a GFCI actually works
A GFCI (ground-fault circuit interrupter) constantly compares the current flowing out through the hot wire to the current flowing back through the neutral wire. In normal operation, those two numbers match almost exactly. The moment there's a mismatch — even a very small one, far too small to trip a standard breaker — the GFCI cuts power in a fraction of a second. That mismatch usually means current is finding an unintended path to ground, which is exactly the condition that causes electric shock.
Common, usually harmless causes
Moisture or humidity reaching the outlet or a connected device is one of the most frequent causes, especially in bathrooms, kitchens, garages, and exterior locations — GFCI outlets are required in exactly these spots for that reason. An aging hair dryer, coffee maker, or holiday lights with slightly degraded insulation can also cause a small, harmless-but-detectable leakage that trips the GFCI. GFCI outlets themselves also wear out over 10-15 years and can become falsely sensitive as they age.
Causes worth taking seriously
A GFCI that trips immediately and repeatedly, with nothing plugged in and no obvious moisture, is more likely pointing to an actual fault in the wiring behind the outlet or somewhere downstream on the same run. This is the scenario where continuing to reset it isn't a fix — it's ignoring a real signal.
How to reset one correctly
Press the 'Reset' button firmly until you hear or feel it click. If it doesn't reset, or resets and then trips again within a few seconds, stop trying and treat it as a real fault rather than a fluke.
One GFCI can protect several outlets at once
A single GFCI outlet is often wired to also protect one or more standard outlets 'downstream' on the same circuit. This causes a common point of confusion: an outlet across the room that isn't itself a GFCI can go dead because a GFCI outlet somewhere else on the same circuit tripped. If a non-GFCI outlet stops working, check for a GFCI outlet elsewhere in the same room, garage, or an adjacent bathroom before assuming the dead outlet itself has failed.
When to call an electrician
Call if a GFCI won't reset at all, trips immediately with nothing connected, trips repeatedly across multiple different devices, or if you're not sure which outlets are on the same GFCI-protected run. It's also worth having any GFCI outlet older than 10-15 years tested, since they can fail in a way that stops protecting the circuit without any obvious symptom.
Not sure if this applies to your home? We're happy to take a look.
Call (703) 256-0444