GFCI won't reset after install

LINE/LOAD reversed (miswire lockout), OR a downstream ground fault on the LOAD circuit See the "GFCI won't reset" troubleshooting workflow. Unplug downstream loads first; if still won't reset, de-energize and swap LINE/LOAD.

TEST button does nothing

No power to the device (breaker off, line conductor not landed) Verify breaker on, verify supply voltage at the LINE terminals with a multimeter.

AFCI breaker trips when the new receptacle is energized

Shared neutral on a multi-wire branch circuit you didn't know about, OR a real arc-fault signature See the "AFCI nuisance trips" troubleshooting workflow. The MWBC case is common in older homes.

GFCI works on its own face but downstream receptacles aren't protected

Downstream cables landed on LINE terminals instead of LOAD De-energize. Move downstream cable to the LOAD terminals (clearly marked).

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ElectricalIntermediate

Install GFCI and AFCI Receptacles

Time

30–90 min

Steps

Pre-check

9 items

Skill

Intermediate

Scope

Install or replace GFCI and AFCI receptacles. Covers the NEC 2023 coverage table (where each is required), the LINE / LOAD wiring convention, multi-device protection from a single GFCI, and what to do when the test button doesn't work.

Safety

Read before starting

Receptacle replacement is the lowest-risk in-residence electrical work, but the failure mode is still the same: a believed-off conductor that is actually energized. NFPA 70E §120.5 verification before any wire is touched. UL 943 self-test GFCIs introduced ~2015 have a miswire-lockout — wires landed on the wrong terminals make the device dead on arrival.

Pre-Check

9 items · complete before you start

Confirm circuit identification at the panel — note breaker number and amp rating
Required
Trace the circuit before you cut power so you know which breaker to lock. Mis-identification is the single most common cause of "I thought it was off" incidents.
Non-contact voltage tester proven against a known-live source IMMEDIATELY before use
Required
Test the tester on a live receptacle in the same room. UL-rated testers can fail silently — proving it on a known source is the only way to trust a zero reading.
Lockout-tagout device for the breaker if anyone else could re-energize it
Required
A breaker lock is ~$8. If you are home alone with the only key, a printed tag on the panel is the minimum.
Insulated tools (1000 V rated screwdrivers and pliers)
Required
Standard hardware-store handles are not insulated for live-electrical work.
Safety glasses and dry, insulating footwear
Required
Concrete/wet floors are a parallel path to ground. Stand on a dry rubber mat if the floor is questionable.
Working flashlight or headlamp independent of room lighting
Required
When the breaker goes off, room lights on the same circuit go with it.
Confirm GFCI vs AFCI vs dual-function requirement for this location per NEC §210.8 / §210.12
Required
GFCI: kitchens, baths, garages, outdoors, basements, laundry, dishwasher, range, microwave. AFCI: most habitable-room circuits. NEC 2023 expanded both significantly.
New device matches the breaker amperage
Required
A 20 A GFCI on a 15 A circuit is fine; a 15 A device on a 20 A circuit is a code violation.
Identify LINE side (incoming) vs LOAD side (downstream) at the box
Required
With breaker on, use a non-contact tester to ID the LINE side BEFORE de-energizing. After de-energization, label it. Then de-energize, verify zero, work.

0 / 35 complete

Pre-identify LINE vs LOAD (with breaker ON)

With breaker ON, use a non-contact voltage tester at each cable in the box
The conductor pair (black + white) reading LIVE is the LINE side (incoming feed)
Any other cable reading dead until a downstream device is turned on is the LOAD side
Mark the LINE cable with tape so you remember after de-energization

⚠ Warnings

Skip this step if the box has only ONE cable — the GFCI protects only its own face, no downstream protection.

Establish electrically safe condition

Turn off the breaker for this circuit
Lock and tag the breaker
Test your non-contact tester on a known-live source
Verify zero energy at the receptacle box
Re-test the tester on the known-live source

✅Continue Gate:Have you (1) turned off the breaker, (2) tested your non-contact tester on a KNOWN-LIVE source, (3) verified zero energy at the conductors you are about to touch, and (4) re-tested the tester on the known-live source to confirm it still works? (NFPA 70E §120.5)

Remove the old receptacle

Unscrew the receptacle from the box and pull it forward
Photograph the wiring BEFORE disconnection
Note which wires were backstabbed (push-in) vs side-screw — you'll re-land on side screws
Disconnect each wire — keep the original LINE side identified

Wire the new GFCI / AFCI receptacle

LINE side (incoming): black to brass screw, white to silver screw — both marked LINE
LOAD side (to downstream protected devices): black to brass LOAD screw, white to silver LOAD screw
GROUND (bare or green) to green screw on the device
Pigtail ground to the box if the box is metal
Wrap the device's screw terminals with electrical tape if the box is metal and crowded — prevents accidental contact with the box
Torque terminal screws to the device label spec — usually 12–20 in-lb

120V Branch Circuit (Receptacles)· NEC Wiring

⚠ Warnings

Modern UL 943 GFCIs miswire-lockout if LINE and LOAD are reversed. The reset button will not click in. If this happens, de-energize and swap the connections.
On an AFCI breaker installation (panel-side), the white pigtail from the AFCI breaker lands on the NEUTRAL bus AND the branch-circuit white lands on the breaker's neutral terminal — NOT directly on the neutral bus.

Mount, restore, and test

Fold the receptacle into the box and secure with the 6/32 screws
Install the cover plate
Restore the breaker
Press TEST — the reset button should pop out and the receptacle should de-energize
Press RESET — the button should click in and power return
Plug in a load on the protected receptacle AND any downstream receptacle to confirm coverage
Mark "GFCI Protected" stickers on any downstream receptacles fed from the LOAD terminals

Code notes

NEC §406.4(D)(3) — replacement receptacles in spaces requiring GFCI must be GFCI-protected.
NEC §210.8(F) — GFCI required on outdoor outlets and most dwelling-unit outdoor branch circuits.

Scope

Safety

Pre-Check

Steps

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