WiremanWireman · GFCI won’t reset or keeps tripping: troubleshooting for electricians · 2023 NEC ·
GFCI won’t reset or keeps tripping
No power to the GFCI, line and load swapped, or a real ground fault downstream.
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How it works
A GFCI compares the current going out on the hot with the current coming back on the neutral. If about 5 mA (0.005 A) goes missing, it assumes that current is going through a person and trips in a fraction of a second. Newer GFCIs also refuse to reset without power or if they’re wired backward.
Every question and answer in this guide. Tap “Step by step” to walk through it.
- What’s it doing?
- RESET won’t stay inTest: Check for power at the LINE terminalsExpect: About 120 V.
- About 0 VNo power reaching the GFCI
- 120 V, wires on LINEWith the breaker off, disconnect the LOAD wires and cap them. Turn it back on and press RESET. Does it reset now?
- Resets with LOAD disconnectedA ground fault downstream
- Still won’t resetThe GFCI has failed
- The incoming cable is on LOADLine and load are reversed
- It resets, then trips againWhen does it trip?
- When one appliance or tool is usedLeakage in that appliance
- In rain or high humidityWater getting into a box or fixture
- With nothing plugged inTest: Look for a shared neutral or a neutral touching groundExpect: OL (open) from neutral to ground, and a neutral that belongs only to this circuit.
- Neutral reads near 0 Ω to groundNeutral touching ground downstream
- Another circuit shares this neutralA shared neutral
- NeitherThe GFCI has failed
- RESET won’t stay inTest: Check for power at the LINE terminalsExpect: About 120 V.