⚡ Safety Devices

GFCI vs AFCI: What's the Difference?

Understanding these lifesaving safety devices, where they're required by code, and why every modern home needs them.

6 min read
Licensed Electricians
Updated Dec 2024

GFCI and AFCI breakers are code-required safety devices that prevent electrical shock and fires. They look similar but protect against completely different hazards. Here's everything you need to know.

What is a GFCI?

GFCI = Ground Fault Circuit Interrupter

What it does: Detects tiny current leaks (ground faults) and shuts off power in 1/40th of a second—fast enough to prevent electrocution.

Protects against: Electrical shock from contact with water, damaged cords, or faulty appliances.

How GFCI Works

A GFCI constantly monitors the current flowing through the hot and neutral wires. If even 4-6 milliamps of current leaks (for example, through water or a person), the GFCI trips instantly. This happens faster than a regular breaker, which only trips on overloads or short circuits.

Where GFCIs Are Required (NEC 2023)

  • Bathrooms: All outlets within 6 feet of sinks or tubs
  • Kitchens: All countertop outlets within 6 feet of sinks
  • Garages: All outlets except dedicated appliances (like garage door openers)
  • Outdoors: ALL outdoor outlets (patios, decks, yards)
  • Laundry rooms: Outlets within 6 feet of sinks or water sources
  • Crawl spaces & unfinished basements: All outlets

Pro Tip: Testing Your GFCIs

Press the "TEST" button on your GFCI outlets monthly. The power should shut off immediately. Press "RESET" to restore power. If it doesn't trip, the GFCI is faulty and must be replaced.

What is an AFCI?

AFCI = Arc Fault Circuit Interrupter

What it does: Detects dangerous electrical arcing (sparking) caused by damaged wires, loose connections, or deteriorating insulation—and shuts off power before a fire starts.

Protects against: Electrical fires caused by arcing faults in wiring.

How AFCI Works

AFCIs use advanced electronics to distinguish between normal electrical arcs (like when you unplug an appliance) and dangerous arcs from damaged wiring. When it detects a hazardous arc pattern, it trips the breaker in milliseconds.

Common causes of dangerous arcing:

  • • Frayed or damaged electrical cords
  • • Loose wire connections in outlets or switches
  • • Nails or screws driven through wires
  • • Rodent damage to wiring insulation
  • • Old, deteriorating wire insulation

Where AFCIs Are Required (NEC 2023)

  • Bedrooms: All circuits (outlets and lighting)
  • Living rooms, family rooms, dining rooms: All circuits
  • Hallways, closets: All circuits
  • Kitchens, laundry rooms: All 120V circuits (new construction)
  • Basically: Almost every living space in modern homes built after 2008

GFCI vs AFCI: Side-by-Side Comparison

Feature GFCI AFCI
Protects Against Electrical shock & electrocution Electrical fires from arcing
Trip Speed 1/40th of a second Milliseconds
Where Required Wet locations (kitchens, bathrooms, outdoors) Living areas (bedrooms, living rooms, etc.)
Cost $15-$30 per outlet or $40-$80 per breaker $40-$80 per breaker
Available As Outlet, breaker, or portable device Breaker only

CAFCI & Dual-Function Breakers

Modern electrical codes often require combination AFCI (CAFCI) breakers, which provide enhanced protection. Some areas also require dual-function breakers that combine AFCI and GFCI protection in one device.

Dual-Function (AFCI/GFCI) Breakers

Best for: Kitchen and laundry room circuits where both protections are required.

  • • Protects against both shock AND fire hazards
  • • Cost: $60-$100 per breaker
  • • Required in some jurisdictions for specific circuits

Do Older Homes Need GFCIs and AFCIs?

Yes—even if your home was built before these were required. While code doesn't retroactively require upgrades, adding GFCIs and AFCIs dramatically improves safety.

Minimum Recommendation:

  • ✅ Add GFCI outlets in all bathrooms, kitchens, and outdoor areas
  • ✅ Add AFCI breakers to bedroom circuits
  • ✅ Test existing GFCIs monthly and replace if faulty

Gold Standard:

  • 🏆 Upgrade entire panel to include AFCI/GFCI protection on all circuits
  • 🏆 Especially important for homes with old wiring (pre-1980s)

Installation Cost

  • GFCI outlet installation $75-$150 each
  • AFCI breaker installation $150-$250 each
  • Dual-function breaker $200-$300 each
  • Full panel AFCI/GFCI upgrade $1,500-$3,000

Worth the Investment

GFCI and AFCI protection can prevent fatal electrocutions and devastating house fires. These devices have saved thousands of lives since becoming code-required. The cost is minimal compared to the protection they provide.

Upgrade Your Home's Electrical Safety

Our licensed electricians can assess your home's protection and install GFCI/AFCI devices where needed. Protect your family today.

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