AFCI Outlets and Breakers Explained

LLast Updated: August 7, 2026

Electricity is one of the most important components in our homes. However, it can also be one of the most dangerous. A flawed electrical system can be the source of power outages, property damage, bodily injury, and even house fires. Thankfully, through modern technology, we are able to implement safeguards into our electrical systems in order to prevent these types of accidents. One example of these safety devices is the AFCI. This device is instrumental in preventing safety hazards caused by arc faults.

Arc Fault Circuit Interrupters are a crucial aspect of any residential building, but unlike their counterpart, GFCIs, AFCIs are less talked about and more misunderstood. So let’s dive into the world of AFCIs.

A residential electrical panel, where AFCI breakers are typically installed to protect individual circuits throughout the home.

What is an Electrical Arc?

In order to explain an AFCI, we must first discuss what an electrical arc is. An electrical arc is a discharge of electric current across a gap in a circuit. Because the air is a poor conductor, the current is able to make its way across the gap by generating an ionized column of gas called a plasma. The plasma creates a bright light and extremely high levels of heat. Arcing is often utilized in a controlled manner for things such as welding, plasma cutting, and lighting.

But when arcing occurs unintentionally, it can be very dangerous. They have been known to cause fires, electrocution, and even explosions. Damaged, frayed or kinked wires, gaps in wire insulation, improperly wired panels, accumulated dust or corrosion can all cause arc faults.

Electrical spark between two wires

Electricity will often try to find the path of least resistance. So if anything is interrupting its intended path (through electrical wiring or connection), it can jump to another conducting material, such as a metal component in an electrical panel. Even if the arc fault is occurring along the current’s intended wiring, the heat that it generates can break down the wire insulation and cause an electrical fire. These fires can then grow and spread to other flammable components of the house. In some cases, these fires will occur behind walls or other hidden areas, causing the fire to intensify significantly before even being detected.

How an arc fault forms: damaged wire insulation overheats, carbonizes, and eventually creates a gap that produces a dangerous electrical discharge.

What is an AFCI?

So while they happen infrequently, arc faults are definitely something we need to avoid – especially in the residential setting. So how do we do that? The AFCI, or Arc Fault Circuit Interrupter.

The Arc Fault Circuit Interrupter’s name pretty much sums it up. The device uses specialized technology that will allow it to detect any abnormal arc occurring along the circuit. When it does, it will interrupt the circuit so that no current can be transmitted through it. By promptly interrupting the circuit upon detecting abnormal arcing, AFCIs can prevent the arc from escalating into a fire. This proactive approach significantly reduces the risk of fire-related incidents.

This is such a crucial aspect of the home that the current National Electrical Code (NEC) now requires that an AFCI be installed on each circuit of the home. On occasion, these devices will be installed at electrical receptacles, but they are more commonly installed at the circuit breaker.

A typical AFCI breaker installation, showing how the load wires and neutral connections integrate into the home’s electrical panel.

AFCI vs GFCI

Do not get the AFCI confused with its close relative, the Ground Fault Circuit Interrupter (GFCI). Both devices are designed to “break” the circuit, but they are triggered by different conditions. As its name suggests, a GFCI will trip the moment it detects a ground fault.

A ground fault occurs when electricity flows to an unintended, grounded conductor, such as a water source or a human body. This is a serious shock risk near water sources, which is why GFCIs are required in all bathrooms and kitchens.

A GFCI outlet, most commonly installed in kitchens, bathrooms, and other areas near water sources.

GFCIs are most commonly installed at the outlet receptacle (as shown above). But they can also be installed at the circuit breaker on individual circuits. In those cases, all the outlets on the circuit will have GFCI protection.  On the contrary, AFCIs are almost exclusively installed at the circuit breaker.

Both AFCIs and GFCIs can be installed on the same circuits together. They work as a team to provide the maximum protection that a circuit can have.

Which Rooms Require AFCI Protection?

Current electrical code requires AFCI protection on circuits serving most of the living spaces in a home. This generally includes:

• Bedrooms
• Living rooms
• Dining rooms
• Family rooms
• Dens
• Sunrooms
• Hallways
• Closets

Over the years, code requirements have expanded to cover more of the home. That means the exact list can vary depending on which version of the National Electrical Code was in effect when the home was built or last updated.

It’s also worth noting that AFCI requirements are separate from GFCI requirements. A single circuit can require both types of protection depending on the room it serves, which is why some panels use combination AFCI/GFCI breakers to cover both hazards at once.

How to Test Your AFCI Breaker

AFCI breakers include a built-in test button. It’s a good habit to test them periodically. Here’s how:

1. Locate your electrical panel and find the AFCI breaker you want to test.
2. Press the test button. If the breaker is working properly, it should trip immediately, cutting power to the circuit it protects.
3. Reset the breaker by switching it fully to the “off” position, then back to “on.” Power to the circuit should be restored.
4. If the breaker doesn’t trip, it may not be functioning correctly. In that case, we recommend having a licensed electrician evaluate it.

Keep in mind that testing an AFCI breaker will cut power to everything on that circuit. It’s a good idea to check what’s connected before testing, especially if anything on the circuit is sensitive to sudden power loss.

Inspecting for AFCIs

Electrical is one of the primary components we inspect when conducting our standard inspections. This is generally one of the main safety concerns for most of our clients. We conduct a very thorough inspection, examining the main panel, testing outlets, fixtures, light switches, and even smoke/CO detectors.

We know the important role the AFCIs play in the home – not to mention they are a code requirement. So our inspectors always make sure to inspect for them. We will test them when possible, but we often can’t when the home is occupied with outlets in use. If there are any missing or defective AFCIs, we will be sure to recommend immediate evaluation and repair.

If you are based in Colorado and in need of inspection services, Scott Home Inspection would love to be of service! With over 18 years of home inspection experience in the CO Front Range, we ensure that you will find the highest quality service in the industry from our inspectors and office staff.

To learn more about us, visit us online or contact us today.

Frequently Asked Questions

What’s the difference between AFCI and GFCI?

An AFCI (Arc Fault Circuit Interrupter) detects dangerous arcing in wiring and helps prevent electrical fires. A GFCI (Ground Fault Circuit Interrupter) detects current leaking to ground and protects people from electric shock. Both devices break the circuit when they detect a problem, but they’re designed to catch different types of hazards, and many homes use both together.

Which rooms require AFCI protection?

Current electrical code requires AFCI protection for circuits serving bedrooms, living areas, dining rooms, hallways, and most other finished spaces in the home. Requirements have expanded over the years, so the exact rooms required can depend on when the home was built.

Do older homes need to be retrofitted with AFCI breakers?

No. Homes built before AFCI requirements were in effect are generally not required to be retrofitted.

How do I test an AFCI breaker myself?

Most AFCI breakers have a test button on the breaker itself. Pressing it should cause the breaker to trip, cutting power to that circuit. If it doesn’t trip, or won’t reset afterward, it may not be functioning properly and should be evaluated by a licensed electrician.

Why didn’t my home inspector test every AFCI breaker?

Inspectors will test AFCI breakers when possible. Testing isn’t always practical in an occupied home, though since tripping a breaker will cut power to anything plugged into that circuit. If an AFCI appears missing or defective, your inspector will recommend further evaluation.