Why Does My GFCI Keep Tripping?

A GFCI compares the current leaving on the energized conductor with the current returning on the neutral. If they differ by roughly 5 milliamps, it trips.

Five milliamps is a tiny amount — about 0.005 amps, thousands of times below the circuit's overcurrent rating. That extreme sensitivity is deliberate: it's set below the level at which current across the chest becomes dangerous. It also means several small, individually harmless leakage paths can add up to a trip.

Diagnose from the pattern

A GFCI trips at roughly 5 milliamps of imbalance. That is a real measurement, not a fault in the device — so the first assumption should be that it is detecting something, not malfunctioning.

The five causes

1. Moisture

The most common cause by a wide margin, and the reason GFCIs are required in these locations in the first place.

Water bridges a path from an energized conductor to ground. It doesn't take much — condensation inside an outdoor box, rain driven behind a cover, a damp basement wall, spray near a kitchen sink.

Where to look:

• Outdoor receptacles — is the in-use cover intact and closing? Is the gasket sealing?
• Water entering the box from behind the siding rather than the front
• Bathroom receptacles near a shower
• Basement or crawl-space receptacles after rain

Test: if the trip correlates with weather, it's moisture. Let the box dry thoroughly, then reset.

2. A failing appliance

An appliance with degraded insulation leaks current to its chassis and then to ground. This is the GFCI catching a genuine fault — and it's the fault that would otherwise be waiting for a person to complete the circuit.

Frequent offenders: older refrigerators and freezers, well pumps, sump pumps, outdoor lighting, pressure washers, older power tools, and heating elements in appliances.

Test: unplug everything on the circuit, reset, and reconnect items one at a time with a few minutes between each.

3. Accumulated leakage from many devices

Every appliance leaks a small amount of current — a fraction of a milliamp, by design, through filter capacitors in its power supply. Individually negligible. But a long circuit with many electronic devices can total several milliamps, and adding one more pushes it past 5.

Symptom: the GFCI trips only when everything is running, with no single item responsible.

Fix: split the load across circuits, or move the highest-leakage devices elsewhere. Long circuits with many devices are the usual scenario.

4. A wiring fault

A shared or crossed neutral, a damaged cable, a neutral touching ground somewhere downstream, or a device miswired so the neutral connects to the wrong terminal.

Symptom: trips with nothing plugged in and no moisture present.

That combination eliminates loads and moisture, leaving the wiring or the device. This one needs an electrician — see why does my breaker keep tripping for the parallel diagnosis on standard breakers.

A specific case: a shared neutral between two circuits will trip a GFCI reliably, because current returning on the shared neutral isn't the current the GFCI sent out.

5. The GFCI itself has worn out

GFCIs contain electronics that degrade. Manufacturers commonly suggest replacement after roughly 10–15 years.

Symptoms: won't reset even with everything disconnected; trips randomly with no pattern; fails its own TEST button; feels loose or the buttons don't click properly.

Replacement is inexpensive relative to the diagnosis time.

A diagnostic order

1. Is it wet, or was it recently? Dry the box thoroughly and retry.
2. Unplug everything on the circuit. Remember the GFCI protects downstream receptacles too, so "everything" may span rooms.
3. Reset. Holds? Reconnect one item at a time.
4. Still trips with nothing connected? Wiring fault or failed device. Try replacing the GFCI first — it's the cheap test. If a new one also trips, it's the wiring, and that's an electrician call.
5. Trips only under full load? Accumulated leakage. Redistribute.

Finding the right reset button

A single GFCI receptacle protects everything downstream on the circuit, so the tripped device may be nowhere near the dead outlet. Check, in this order: bathrooms, garage, outdoor receptacles, basement, and the panel (for a GFCI breaker, which has its own TEST button in the panel).

This is exactly the situation an accurate panel directory solves — see how to label an electrical panel.

Can I replace a tripping GFCI with a standard breaker?

Don't remove GFCI protection to stop the tripping. It's required in those locations because they're where shock risk is highest, and removing it is a code violation.

Don't replace a GFCI receptacle with a standard one. Same problem.

Don't ignore repeated trips. A GFCI that trips regularly is reporting a leakage path. That path exists whether or not the device is there to catch it.

Testing

Press TEST monthly. It should trip and cut power. Press RESET to restore.

A GFCI that doesn't trip on TEST has failed and gives no other sign. This is the only way to know it still works.

Code reference

The requirements behind this guide, for looking up in your adopted edition:

• NEC 210.8 — GFCI protection for personnel

Code editions and local amendments vary by jurisdiction. Confirm the adopted edition with your AHJ before relying on any specific article.

Where to go next

• GFCI vs AFCI
• GFCI outlet requirements by room
• Why does my breaker keep tripping
• How many amps does an appliance use

More in our electrical panel guides.