What does a GFCI do, and what does an AFCI do?
A GFCI compares the current going out on the hot wire with the current coming back on the neutral. If some of it is missing, it’s leaking somewhere else, maybe through water or through a person. Under UL 943, a Class A GFCI (the kind in homes) trips when the leak reaches 6 milliamps and must not trip below 4. That’s a tiny fraction of what it takes to trip a 15-amp breaker, which is the point: a regular breaker protects the wire, and a GFCI protects you.
An AFCI listens for arcing, the sparking you get from a loose connection, a crushed cord or a nail through a cable. The Consumer Product Safety Commission puts it plainly: ordinary breakers “do not respond to early arcing and sparking conditions.” AFCIs address fire; GFCIs address shock.
A dual-function breaker does both in one device. GFCI protection can also come from a GFCI receptacle, which protects the outlets wired after it. AFCI protection usually comes from a combination-type breaker in the panel.
Where does California require GFCI protection?
In a house, 210.8(A) requires GFCI protection for all 125-volt through 250-volt receptacles on single-phase circuits of 150 volts or less to ground in eleven kinds of location: bathrooms; garages and accessory buildings; outdoors; crawl spaces; basements; kitchens; within 6 feet of a sink; boathouses; within 6 feet of a tub or shower; laundry areas; and indoor damp or wet locations. The jump from 125-volt only to 125–250 volts came in the 2020 NEC, so a 240-volt dryer or range receptacle in one of those spaces is covered too.
The 2023 edition, which is what the 2025 California Electrical Code is built on, pushed further in kitchens. GFCI used to apply only to receptacles serving the countertop. Now it covers the kitchen, which picks up the refrigerator, disposal, microwave and range receptacles, and it adds areas with a sink and permanent provisions for food or drink prep, like a wet bar.
It also added 210.8(D), a list of specific appliances that need GFCI whether they plug in or are hardwired: dishwashers, electric ranges, wall ovens, cooktops, clothes dryers, microwaves and sump pumps, among others, when they’re rated 150 volts to ground or less and 60 amps or less. The GFCI device has to be readily accessible, so a GFCI receptacle behind a range doesn’t count; that’s often a GFCI breaker in the panel instead.
We didn’t find a California amendment to 210.8 in the material we read. The inspector and your city’s adopted edition have the final word.
What about outdoor outlets and the AC condenser?
210.8(F), added in the 2020 NEC, requires GFCI on outdoor outlets, not just receptacles, supplied by single-phase circuits of 150 volts or less to ground and 50 amps or less in the 2023 text (one trade write-up quotes 60 amps, which may be newer wording). That swept in hardwired outdoor equipment, including air conditioners and heat pumps. Some heat pumps and mini-splits tripped their GFCIs for no good reason, so NFPA issued TIA 23-3, an exception for listed HVAC equipment written to expire on September 1, 2026.
It did expire. In August 2026 a new proposal, TIA 1924, asked NFPA to push the date to September 1, 2028; public comments closed September 9, 2026, and no decision had been published when we checked. If you’re replacing a condenser or heat pump this fall, ask the building department how it’s treating 210.8(F) before the permit, not at the inspection.
Where does California require AFCI protection?
210.12(A) requires AFCI protection on 120-volt, single-phase, 15- and 20-amp branch circuits supplying outlets or devices in kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas and similar rooms. In practice that’s most of a house. Bathrooms, garages and outdoors aren’t on the AFCI list; they’re GFCI territory.
The usual way to meet it is a combination-type AFCI breaker, which protects the whole circuit from the panel out. An outlet branch-circuit AFCI receptacle at the first outlet is allowed when the wiring from the panel to that outlet is in metal conduit or metal-clad cable, and there’s a system-combination option as well.
When did these rules show up?
GFCI requirements started with pool lights in the 1968 NEC and have grown nearly every edition since. AFCIs arrived in the 1999 NEC for bedrooms. The table lists the edition that added each requirement; California and each city adopt editions later than NFPA publishes them, so a house built in a given year was wired to an older edition than that year.
When the NEC added GFCI and AFCI requirements for homes| NEC edition | GFCI added | AFCI added |
|---|
| 1968 | Underwater swimming pool lights | — |
|---|
| 1971 | Outdoor receptacles, receptacles near pools, construction sites | — |
|---|
| 1975 | Bathroom receptacles | — |
|---|
| 1978 | Garage receptacles | — |
|---|
| 1987 | Kitchen receptacles within 6 ft of the sink, boathouses, hydromassage tubs | — |
|---|
| 1990 | Crawl spaces and unfinished basements | — |
|---|
| 1996 | All kitchen countertop receptacles, accessory buildings | — |
|---|
| 1999 | — | Bedroom circuits (required as of January 1, 2002) |
|---|
| 2005 | Laundry and utility sinks | Combination-type AFCIs (required as of January 1, 2008) |
|---|
| 2008 | — | Family, dining and living rooms, parlors, libraries, dens, sunrooms, recreation rooms, closets, hallways |
|---|
| 2014 | Within 6 ft of any sink, dishwashers, shower stalls | Kitchens and laundry areas |
|---|
| 2020 | 125–250 V receptacles in the listed areas, all basements, outdoor outlets (210.8(F)) | List unchanged |
|---|
| 2023 | All kitchen receptacles, areas with sinks and food or drink prep, specific appliances (210.8(D)); HVAC exception until Sept 1, 2026 | — |
|---|
Why do they trip, and what should you do?
Many trips are the device doing its job. A GFCI that trips when it rains is telling you water is reaching something live, usually an outdoor outlet, a landscape light or a fixture box. An AFCI that trips when you plug in an old lamp may be hearing a worn cord. Leviton’s advice for a GFCI trip is to look at the device and the cords for discoloration or loose plugs, note what you were using when it tripped, and unplug the suspect.
Siemens’ AFCI troubleshooting guide adds loose bulbs, cords pinched under furniture and blackened plugs, and on newer work, a shared neutral between two circuits, which an AFCI won’t tolerate. Square D’s QO and Homeline arc-fault and dual-function breakers can report what they tripped on through a trip-timing test Schneider calls Time Saver Diagnostics.
When the trip doesn’t have an obvious cause, or it trips with nothing plugged in, it’s a wiring question. The breaker trip troubleshooter walks through the safe checks in order, and we handle the rest under troubleshooting and code corrections. Never replace a GFCI or AFCI breaker with a plain one to stop the trips.
How often should you test them?
Monthly. ESFi and Leviton both say it. Plug a lamp into a GFCI outlet, press TEST, and the lamp should go out; press RESET and it comes back. AFCI and dual-function breakers have a TEST button on the breaker face, and the handle should drop to the tripped position when you press it.
If TEST does nothing, or the device won’t reset, it isn’t protecting anything. Leviton says a GFCI that fails the test should be replaced by a licensed electrician. Swapping GFCI receptacles and adding AFCI protection is routine outlet and switch work.
Does an older house have to be brought up to today’s code?
Not just because the code changed. Neither 210.8 nor 210.12 makes you retrofit a house nobody is working on. The triggers are new work, extensions, modifications and replacements.
For AFCI, 210.12(D) says that when branch-circuit wiring in one of the listed rooms is modified, replaced or extended, that circuit gets AFCI protection, either a combination AFCI breaker or an outlet branch-circuit AFCI at the first outlet. The one exception is an extension of 6 feet or less that adds no outlets or devices. Separately, 406.4(D)(4) says a replacement receptacle in one of those rooms has to be AFCI protected, with narrow exceptions. So adding an outlet in a 1970s bedroom usually means an AFCI breaker for that circuit. Ask whether a like-for-like swap in a bathroom, kitchen or garage triggers GFCI in that spot too.
Even where nothing is required, GFCI protection in bathrooms, the kitchen, the garage and outdoors is the upgrade the code has pushed the longest. ESFi credits GFCIs with helping cut home electrocutions in half since the 1970s.
