GFCI vs AFCI: What's the Difference?

Electrical safety devices have become an essential part of modern homes in Ontario. If you're planning a renovation, adding new circuits, replacing an electrical panel, or preparing for an ESA inspection, you've likely heard the terms GFCI and AFCI.

Although they may appear similar, they protect against completely different electrical hazards. Understanding when each type of protection is required can help you make informed decisions while keeping your home safe.

A GFCI protects people from electric shock, while an AFCI helps prevent electrical fires. Modern residential electrical systems often require both types of protection.

What Is a GFCI?

A Ground Fault Circuit Interrupter (GFCI) monitors the electrical current flowing through a circuit. If it detects even a small imbalance caused by electricity flowing somewhere it shouldn't, it disconnects power within milliseconds to reduce the risk of serious electrical shock.

Where Is GFCI Protection Commonly Used?

• Bathrooms
• Kitchen countertop receptacles
• Garage outlets
• Outdoor receptacles
• Laundry rooms
• Unfinished basements
• Areas located near sinks or water sources

Because water significantly increases the risk of electric shock, GFCI protection is commonly installed anywhere moisture may be present.

What Is an AFCI?

An Arc Fault Circuit Interrupter (AFCI) works differently. Instead of detecting current leakage, it continuously monitors the electrical waveform for dangerous arc faults that can occur inside damaged wiring, loose electrical connections, or deteriorated devices.

These arc faults generate intense heat that may ignite surrounding building materials long before a standard breaker trips.

Many electrical fires begin with damaged wiring hidden behind finished walls. AFCI protection is specifically designed to detect these hazardous conditions before they become a serious fire risk.

GFCI vs AFCI: What's the Difference?

Where Are GFCI and AFCI Required in Ontario?

Ontario Electrical Safety Code contains specific requirements for both GFCI and AFCI protection depending on the type of installation, the location of receptacles, and the scope of electrical work being performed.

Because every project is different, a licensed electrician can determine exactly which type of protection is required before work begins.

Can One Breaker Provide Both?

Yes. Many new electrical panels now use Dual Function Breakers, which combine both GFCI and AFCI protection into a single breaker. This simplifies installation while providing comprehensive protection against both electrical shock and dangerous arc faults.

Electrical codes continue to evolve as new technologies improve residential safety. Upgrading protection devices during renovations is one of the most effective ways to improve your home's electrical safety.

Final Thoughts

GFCI and AFCI devices serve different purposes, but both are important components of a safe electrical system. Whether you're renovating an older home, upgrading an electrical panel, or adding new circuits, installing the proper protection helps keep your family and property safe while ensuring your electrical system meets current Ontario safety requirements.