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How do you replace a GFCI outlet?

Updated August 2026

20–30 minutes · Moderate DIY

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Swapping a GFCI receptacle runs 20 to 30 minutes on a $15–25 device, and the entire job hinges on one distinction: the incoming pair from the panel lands on LINE, and any downstream pair lands on LOAD. Reverse them and the device either refuses to reset or powers the outlet while protecting nothing, which is the worse of the two outcomes because it looks like success. Replace a GFCI when it will not hold a reset, when it fails the TEST button, when plugs fall out of it, or when it passes 10 to 15 years of age. This is a shock-risk job, so the breaker goes off and stays off.

What you need

Before you start: Switch the breaker off and confirm with a non-contact voltage tester at both slots and at every conductor in the box before your hands go in, because a single box can hold two circuits and a dead outlet does not guarantee a dead box. Four findings mean you close it up and call an electrician: dull silver solid conductors, which indicate the aluminum branch wiring used roughly from 1965 to 1975; melted or discolored insulation at the terminals; a box with no ground wire; and a spliced mess you cannot trace. A GFCI on an ungrounded two-wire circuit is permitted, but it must carry the "No Equipment Ground" sticker supplied in the box. Never work this outlet live.

Steps

  1. Confirm the device is actually the problem: it fails TEST, will not latch on RESET, feels loose, or the manufacture date stamped on the back or side puts it past 10 to 15 years.
  2. Switch the breaker off, then verify. Touch a non-contact tester to both slots, plug a lamp in, and try the wall switch that might feed it. Assume nothing.
  3. Photograph the wiring before a single screw moves, then unscrew the cover plate and the two mounting screws and ease the receptacle out of the box.
  4. Identify LINE versus LOAD on the old device. LINE is the feed from the panel, LOAD is the pair carrying protection downstream. Many boxes have only one cable, which makes this trivial.
  5. If two cables are present and the old labels are gone, separate every conductor so nothing touches, cap them, switch the breaker on, and test to find the hot black-and-white pair. That pair is LINE. Switch the breaker off again before you continue.
  6. Land the wires on the new device: LINE hot to the brass LINE screw, LINE neutral to the silver LINE screw, the downstream pair to the LOAD terminals, and the bare copper to the green ground screw. Strip three quarters of an inch of insulation and tighten each screw firmly.
  7. Peel the yellow LOAD warning sticker off only if you are actually using the LOAD terminals. It exists to stop exactly the mistake it covers.
  8. Fold the conductors back into the box in an accordion shape, seat the device, screw it in plumb, and fit the cover plate.
  9. Restore the breaker, press RESET, then TEST, then RESET again. Finish with a plug-in GFCI tester at this outlet and at every downstream outlet, the only way to prove the protection reaches where you think it does.
  10. Write the install date on the back of the cover plate and set a 10-year reminder so the next person does not have to guess.

Or hire it out

An electrician charges $120–250 to replace a GFCI receptacle, of which $75–150 is the minimum service call, so it is worth batching several devices into one visit. The receptacle itself is $15–25 at any hardware store.

Done. Now the part everyone skips: doing it again on schedule. Log it in OnOtto and the next reminder for GFCI replacements sets itself.

Log this task, get the next reminder

Frequently asked questions

What actually goes wrong if I swap LINE and LOAD?

On most modern GFCIs, nothing works: the device ships with an internal lockout that refuses to reset when power arrives at LOAD, which is a deliberate safeguard. On older stock, the outlet powers up normally while its sensing circuit sits on the wrong side of the fault, leaving both that receptacle and everything downstream unprotected. That failure is invisible without a plug-in tester, which is exactly why the last step of the job is testing every outlet on the run.

Which outlets are required to have GFCI protection?

Current code requires it for receptacles in kitchens, bathrooms, garages, unfinished basements, laundry areas, crawlspaces, outdoors, and anywhere within 6 feet of a sink, plus dishwashers and several hardwired appliances. Older houses are not forced to retrofit, but any receptacle you replace in those areas should come back as GFCI protected. One device protecting downstream outlets satisfies it, and a $40–70 GFCI breaker at the panel is the cleaner answer when a circuit has many wet-location outlets.

Should I install a GFCI, an AFCI, or a dual-function device?

They solve different problems. GFCI watches for current leaking to ground and protects people from shock in wet areas. AFCI detects the erratic signature of arcing in damaged wiring and protects the house from fire, and code now requires it on most living-space circuits. Dual-function devices do both and cost $30–50 at the receptacle, $50–80 at the breaker. For a kitchen or bath swap, a plain GFCI receptacle is the correct part.

How do I know when a GFCI is due rather than just tripping?

Age plus behavior. The internal components degrade over 10 to 15 years, faster in a hot garage or a damp exterior box, and a device that fails the monthly TEST press has already stopped protecting anyone. If it trips repeatedly but tests fine, the circuit is the problem, not the device, so read the tripping causes first. The replacement interval and the cost of skipping tests cover the rest.

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