Are arc fault circuit interrupters (AFCIs) worth the cost? Short answer: Absolutely.

When Wade Anderson awoke one day to find no electricity in his Sherwood, Oregon, bedroom, he traced it to a burned-out open wire — a fire hazard. He called an electrician to add a new circuit and install arc fault circuit interrupters, also known as AFCI, to his breakers.

“Had I installed AFCIs in that bedroom earlier, the bad circuit would have been revealed sooner, avoiding a close call on a fire,” the Angie’s List member says. “Arc faults are more likely as wiring ages, so AFCIs are a wise upgrade for older homes.”

Experts say AFCI breakers can prevent fire hazards by cutting off power in the breaker box as soon as they detect the “electric signature” — sharp spikes and drops in voltage — that indicate a fault. Arc faults occur when electricity discharges at unintended points, such as corroded or loose wires, creating dangerous sparks or excessive heat. The National Fire Protection Association says arcs are the most common cause of residential electrical fires.

Michael Johnston, executive director of standards and safety for the National Electrical Contractors Association, strongly recommends them for all homes, and installed several in his own home when he moved in, even though it was less than a decade old.

“It’s like having a policeman there constantly monitoring your system and stopping the arc as soon as it happens,” he says. “An AFCI breaker is designed to react within one-tenth of a second of an arcing event and open the circuit.”

Seth Silbaugh, owner of an electrical contracting company calls this an improvement over previous generations of breaker technology. “A loose connection can cause a fire, but it won’t trip a circuit breaker,” he says. “An AFCI can pick that up and cut it off.”

AFCI technology developed in the 1990s and slowly began to take hold in the National Electrical Code. New versions call for AFCI breakers in nearly all of the habitable areas of the house. Homes built prior to the NEC’s adoption of AFCI in the last decade aren’t required to have it, but Silbaugh says the code calls for AFCI breakers when adding new circuits or upgrades to the system.

Johnston says the cost of adding this work to older homes can vary widely, depending on the age of the electrical panel.

“The breaker itself costs about $40 and takes an hour or two to install four or five of them, unless there are troubleshooting problems,” he says. “So you might be looking at a few hundred dollars. But some older panels won’t accept the new AFCI devices, so you’d need to upgrade the panel.”

Silbaugh says he sometimes comes across this problem, and that panel upgrades can cost anywhere from a few hundred to a few thousand dollars. Johnston says in cases where panel upgrades aren’t feasible, device-based AFCI can be installed directly in outlets at a lower cost.

Silbaugh points out that AFCI can work in conjunction with ground fault circuit interrupter (GFCI) technology, and says this remains particularly important in bathrooms.

“GFCI protects the end user from electric shock,” he says. “But a circuit can be protected by both AFCI and GFCI at the same time.”

One lingering criticism claims that AFCI trips too easily, which Anderson echoes.

“They’re pretty sensitive,” he says. “A circular saw can trip them, which I’ve experienced.”

Silbaugh says AFCI circuits do tend to be more sensitive, especially in older houses such as Anderson’s 1968 home, but technology improvements have lowered that problem. “The newer ones are a lot better than the ones from even five or six years ago,” he says. “They’ll still trip on occasion if something like a vacuum or a treadmill creates an electric signature the AFCI interprets as a problem, but it’s not a reason not to put them in. There are certain inconveniences, but the safety benefits outweigh them.”