There is a lot of information out there about the benefits of GFCI and AFCI and the places where they must or should be used. But are there any circumstances where you're better off without them? If I won a free box of dual-function GFCI/AFCI breakers, would there be any reason not to use one for every circuit in my house?

  • 9
    Everybody seems to dislike AFCI and GFCI devices, blaming them for nuisance or false trips. The fact is, they're there to protect you. Maybe we should stop blaming these devices, and start pointing the finger at manufacturers who make products that cause these devices to trip. These devices have been around for some time now, there's no excuse for manufacturers to not make their devices compatible with them.
    – Tester101
    Sep 23, 2015 at 0:13
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    If a device is leaking current, or making dangerous arcs. The device is faulty, not the AFCI/GFCI that detects the problem.
    – Tester101
    Sep 23, 2015 at 0:15
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    While there is a lot of useful information here, it's a little frustrating that nobody actually answered your simple question, "would there be any reason not to use one for every circuit in my house?"...I'm trying to figure out if there are any downsides to AFCI breakers or outlets because I'm about to put in 2 x 20 AMP breakers and I would rather just use a GFCI/AFCI combination IF there is no downside to them...
    – Soundfx4
    Oct 16, 2016 at 19:54
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    @Soundfx4 - There are "downsides" (cost, nuisance trips) but the basic simple answer is that 2014 CODE REQUIRES THEM everywhere if you do work. There's also the upside of still being alive and your house not on fire.
    – Mazura
    Dec 7, 2016 at 4:47
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    @Mazura If you could see my house, you might think twice about it not being on fire being an upside :P but no, that's awful to say and I'm honestly very thankful that it's not and hope that it never is. I ended up using a combination breaker because it was cheaper than a dedicated GFCI (which was all that was required where I installed it).
    – Soundfx4
    Nov 19, 2017 at 0:27

6 Answers 6


For all new construction residential dwellings the answer is not too complicated.

For older homes with existing wiring the answer is not as easy. A qualified electrician would need to assess the wiring conditions and even then only by trail and error could they determine if ARC-fault protection would be able to work. In some cases using an ARC-Fault receptacle downstream may be an option, whereas a complete rewire of the existing branch circuit may be needed.

I've elaborated on the answer breaking it up into residential and commerical establishments for educational purposes.

Residential AFCI Requirements

  • All habitable rooms that contain 120 volt 15 or 20 Amp branch circuits require ARC-fault protection. This includes kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas.
  • Exceptions:

    • Bathrooms, unfinished basements, garages, and outdoors.
    • Fire alarm system installed in accordance with 760.41( B) or 760.121( B) is installed in RMC, IMC, EMT, or steel-sheathed cable, Type AC or Type MC, meeting the requirements of 250.118, with metal outlet and junction boxes, AFCI protection shall be permitted to be omitted. (This is mainly in condominiums and not so much in traditional houses.)
    • Existing installations are not required to be updated with ARC-fault protection unless modification to the wiring is done.

      • Exception: AFCI protection shall not be required where the extension of the existing conductors is not more than 1.8 m (6 ft) and does not include any additional outlets or devices.

Residential GFCI Requirements

  • All 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms, even if the receptacle is part of the bathroom lights, or if you have a washing machine in the bathroom it too requires GFCI protection.
  • Garages, sheds, and accessory buildings located at or below grade.
  • All outdoor receptacles.
  • All crawl space receptacles.
  • All unfinished basements.
  • All kitchen countertop areas.
  • All dishwashers.
  • All pool motors, spas, and pumps
  • All receptacles within 6' of any sink.
  • All boathouses
  • All laundry areas
  • Exceptions:
    • A receptacle supplying only a permanently installed fire alarm or burglar alarm system shall not be required to have GFCI protection.
    • Receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.
    • Receptacles installed for disposals and trash compactors are not required to be protected by GFCIs. A receptacle( s) installed behind a refrigerator is installed to supply that appliance, not the countertop, and is not covered by the kitchen countertop GFCI requirement.

Commercial ARC-fault Requirements

  • Dormitory units are required to have ARC-fault protection.

Commercial GFCI Requirements

  • All 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms, kitchens, rooftops and outdoors, 6' from a sink, indoor wet locations, locker rooms, garages, service bays, and similar areas.
  • All vending machines.
  • All pool motors, spas, and pumps.
  • All electric drinking fountains.
  • Exceptions:
    • In industrial laboratories, receptacles used to supply equipment where removal of power would introduce a greater hazard shall be permitted to be installed without GFCI protection.
    • For receptacles located in patient bed locations of general care or critical care areas of health care facilities other than those covered under 210.8( B)( 1), GFCI protection shall not be required.
    • Receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.
    • In industrial establishments only, where the conditions of maintenance and supervision ensure that only qualified personnel are involved, an assured equipment grounding conductor program as specified in 590.6( B)( 2) shall be permitted for only those receptacle outlets used to supply equipment that would create a greater hazard if power is interrupted or having a design that is not compatible with GFCI protection.
  • 9
    That was very informative and a lot of very useful information, thank you!! However, the OP question was a very specific hypothetical situation and you didn't answer that. He asked if there is any reason to NOT use a GFCI/AFCI combination breaker for every circuit if he obtained a free box of them. So basically, I think he's simply asking what downsides are there to them, if any?
    – Soundfx4
    Oct 16, 2016 at 19:47
  • Very specific? That is hardly true. If you read his subject title correctly he asks "where" and in the contents he asked "why" not. At any rate I answered both. You also missed my explicit explanation that the reason "why" would likely be because of incompatibility of older wiring and thus would entail a complete new circuit in order for the arc faults to work.
    – Kris
    Oct 17, 2016 at 14:04
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    @Kris So any branch circuit above 20 amps does not require AFCI protection?
    – cryptic0
    Jul 8, 2021 at 19:10

GFCIs will often nuisance trip with certain types of loads. For example many motors will trip the GFCI even though there is no leakage to ground. This is why there is an exception for the refrigerator's outlet. It's a good idea to have that on a circuit of it's own with no GFCI.

A GFCI device doesn't generally measure leakage to ground, it compares the current on the hot leg to the current on the neutral leg. Normally the same amount of current should go out as comes back. The premise is, if more current is seen on the hot than the neutral, it is assumed that some current is leaking to ground rather than returning on the neutral - which could mean someone is getting electrocuted - so the device interrupts the current.

I have heard that in some countries (maybe Australia?) there are different grades of GFCI, some are rated for use with motors and inductive loads.

Now AFCI - that one I can't say, I haven't tested it myself firsthand, but a lot of knowledgeable people claim that unlike GFCI, AFCI devices just don't work as intended.

  • Out of curiosity, where does the missing current disappear to with motors?
    – dlf
    Oct 6, 2015 at 20:17
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    @dlf Re. electric motors: "relative motion between the armature of the motor and the magnetic field from the motor's field magnets [causes] this voltage [which] opposes the original applied voltage; therefore, it is called back-electromotive force". CEMF "is the voltage drop in an alternating current (AC) circuit caused by magnetic induction." –Wiki
    – Mazura
    Oct 6, 2015 at 20:55
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    It doesn't disappear, but it may not flow perfectly evenly on the hot and neutral. Oct 6, 2015 at 21:14
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    It doesn't disappear. The current is perfectly even in both sides. It's just that the rapid changes in current due to the brushes engaging and disengaging is not accurately measured by the interrupter. Oct 16, 2016 at 0:17
  • Re. refrigerators: A new Samsung fridge kept tripping my (pre-existing) GFCI. I added a surge-suppressor, then a snubber; neither helped. Then my son read that Eaton GFCIs might help -- switched from Leviton to Eaton, and the problem was solved. fwiw....
    – TextGeek
    Jul 6, 2023 at 12:26

National Electrical Code 2014 requires ground-fault protection for personnel in dwelling units for all 120 volt, single phase, 15 and 20 ampere receptacles installed in the following locations:

  • Bathrooms.
  • Garages
  • Accessory buildings with floors at or below grade that are not intended as habitable rooms.
  • Outdoors, except where receptacles on dedicated circuits are not readily accessible, and are used to supply snow-melting, deicing, or pipeline and vessel heating equipment.
  • Crawl spaces
  • Unfinished basements, unless the receptacle is on a dedicated circuit and used to supply a burglar alarm.
  • Kitchens where the receptacles serve coutertop surfaces.
  • Where a receptacle is within 6 ft. (1.8m) of sinks in other than kitchens.
  • Boathouses
  • Where receptacles are installed within 6 ft. (1.8m) of the outside edge of bathtub and shower stalls.
  • Laundry areas

Arc-fault protection is required in dwelling units for all 120 volt, single phase, 15 and 20 ampere branch circuits supplying outlets and devices installed in:

  • Kitchens
  • Family rooms
  • Dining rooms
  • Living rooms
  • Parlors
  • Libraries
  • Dens
  • Bedrooms
  • Sunrooms
  • Recreation rooms
  • Closets
  • Hallways
  • Laundry areas
  • and all similar rooms and areas

I don't know where you shouldn't install them, I only know where you are required and not required to. I guess you shouldn't install them anywhere they're not required, or you'd be spending money you're not required to spend?

According to the documentation for QO® and QOB Miniature Circuit Breakers, Qwik-Gard GFCIs should not be used as follows:

  • Do not connect to swimming pool equipment installed before adoption of the 1965 National Electric Code
  • Do not connect to electrical ranges or clothes dryers whose frames are grounded by a connection to the grounded circuit conductor.
  • Do not use as a main circuit breaker in a panelboard or in reverse connected (backfed) applications.
  • 2
    So, every convenience outlet in a dwelling needs to be either GFCI or AFCI, depending on the situation? I'm hard-pressed to come up with a room in a house that's not listed here. The answer seems to be nowhere, save for the few "dedicated" exceptions (none of which seem likely to apply for most homes).
    – Mazura
    Sep 26, 2015 at 3:32
  • 1
    Well; an unmandated breaker isn't a waste of money if it ends up protecting you from a dangerous situation. It's sounding like the answer is "you might as well install them everywhere up to the limits of your budget"?
    – dlf
    Sep 29, 2015 at 12:33
  • "AFCIs are not required in attics" - That's about it I guess. Unless attics fall under "all similar rooms and areas".
    – Mazura
    Dec 7, 2016 at 4:33

A GFCI cannot be used where two circuits have a shared neutral line. It is rare, and probably violates all versions of the National Electric Code since 1970, or earlier, but I encountered a situation where I installed a GFCI circuit breaker in a bathroom outlet circuit in a house that was built around 1958. The GFCI kept tripping every hour or two for no apparent reason, so I removed it and replaced it with the original circuit breaker. Later, while performing remodeling that involved removal of drywall, the cause became apparent. Pinching pennies, the builder's electrician had connected the neutral wire to the refrigerator outlet in common with the neutral to the bathroom outlet, instead of running separate neutral and hot wires from the two circuit breakers in the main breaker panel to the two outlets. Each time the compressor motor in the refrigerator started, it created a current imbalance in the bathroom GFCI breaker, causing it to trip.

  • Yes you can GFCI protect a properly wired shared neutral circuit (multi-wire branch circuit); however, you must use a two-pole GFCI breaker to do so Jun 12, 2020 at 22:13
  • @ThreePhaseEel — Granted, but I don't believe Stab-Lok two-pole GFCI circuit breakers were available at the time, in the mid-1990s. They were introduced a decade later by Federal Pioneer (Canada) and the cost in 2020 is steep, around $320 each. for 15A 120V/240V rating. Even then, you end up with a unit that has a 50/50 chance of tripping properly on overload. In the event, rewiring was cheaper and safer. (See the history of the Federal Pacific Stab-Lok circuit breaker debacle and how they lost their UL rating due to fraudulent testing.)
    – Andrew P.
    Jun 18, 2020 at 16:42
  • I'm quite familiar with the Stab-Lok debacle myself, and I agree that rewiring (and tossing that Fire Protection Eliminated(!) panel in the scrapheap) was the better solution in your specific case; I'm just mentioning that for people with not-so-janky panels, a two-pole GFCI may be the best way to go Jun 18, 2020 at 22:30

Do not install GFCIs for dedicated fridge outlets (the fridge does however need to be AFCI'ed - if it's new work).

According to @Tester101's answer (drawing from the 2014 NEC) there are two exceptions.

GFCI required:

  • Outdoors, except where receptacles on dedicated circuits are not readily accessible, and are used to supply snow-melting, deicing, or pipeline and vessel heating equipment.

  • Unfinished basements, unless the receptacle is on a dedicated circuit and used to supply a burglar alarm.

From what I can tell (I do not have a copy of the 2014 NEC), these are the only two exceptions to the need of either a GFCI or an AFCI - for new work. Apparently, all other locations that do not require GFCIs, require AFCIs - for new work.

IMO, you should not arbitrarily swap out outlets; old work only has to have complied with code at the time of installation. However, I see little reason not to swap out any and all convenience outlets to GFCI's (if you want to). Unless required by code for the new work I'm doing, there's no way I'd put hundreds of dollars worth of food on a GFCI outlet that's dedicated to a fridge.

Code jargon aside, the OP asked for any reason you wouldn't want either type of outlet installed. My number one concern about them failing is the spoiled food you'll have in your fridge while trying to better protect an outlet that you'd have to pull the fridge out to use otherwise.

IMO, this is the one place "you are better off without one."

All statistics are to be taken with a grain of salt; mildly relevant:

Each year, there is an estimated average of 60 electrocutions associated with consumer products. –www.esfi.org

CDC estimates that each year roughly 1 in 6 Americans (or 48 million people) get sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases. –www.cdc.gov

Pick your poison.

  • Check the date on that post, that information is outdated (and was not accurate even at the time).
    – Tester101
    Sep 26, 2015 at 2:22
  • @Tester101 - Then why is it still there? ; flagged...
    – Mazura
    Sep 26, 2015 at 2:30
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    It's still there because nobody has time to reread all the answers on the site. Besides, you shouldn't believe everything you read on the internet.
    – Tester101
    Sep 26, 2015 at 2:36
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    In 2011 I wasn't as knowledgeable about the NEC as I am now, and I've learned quite a bit since then. If you looked at the edit, you'd see that I simply fixed a typo. In the early days of the site (and even still today), we all trusted Shirlock, as he was the only one actually working in the field.
    – Tester101
    Sep 26, 2015 at 2:58
  • 1
    You'll also note that the 2008 version of NEC didn't require GFCI protection in as many places (there were a lot of exceptions).
    – Tester101
    Sep 26, 2015 at 3:02

Modern electrical code does not restrict installation of GFCI everywhere. All modern, quality equipment should not have enough leakage to trip GFCI.

You can't install GFCI if equipment you're using is old or poor quality and leakage current is enough to trip GFCI (constantly or intermittently). IMO it is better to fix or replace the equipment, but that's another story.

In summary, where fear of negative effects of accidental trip of GFCI circuit would outweigh benefits of this protection. Usual debate case that I've encountered: refrigerators, sump pumps, and other critical equipment. This is a matter of opinion, however, so you should make a decision for yourself. I'm just a dude with an internet connection.

  • Hm. Good point. My sump pump is currently plugged into a GFI simply because that's the power strip I had on hand. Guess I should fix that
    – keshlam
    Sep 22, 2015 at 23:14
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    Is that anecdotal or real research?
    – bib
    Sep 22, 2015 at 23:26
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    I wouldn't suggest "fixing" that specifically right way. There are pros and cons to having GFCI on sump pump (e.g. having a flood because GFCI tripped unnecessarily vs getting electrocuted if you have a flood because of pump failure and walk into water with power on). I'm just saying I've seen a lot of strong opinions on this.
    – Serge
    Sep 22, 2015 at 23:55
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    If this equipment is so critical, manufacturers should design it to work with AFCI/GFCI devices.
    – Tester101
    Sep 23, 2015 at 0:17
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    @TTT it takes 0.005 or so amps to trip GFCI outlet. It takes 15+ amps to trip a circuit breaker. There are plenty of conditions that can occur that will cause current flow in the flood scenario that is well below circuit breaker max current, but also well above to kill a person. So definitely not guaranteed.
    – Serge
    Jan 2, 2020 at 21:28

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