Ideally, you want to be able to take your home’s electrical system for granted. It should power your lights and appliances reliably, safely and invisibly.
But it’s important to notice warning signs that an experienced professional should examine a system.
Our researchers compiled these indicators, based on interviews with highly rated electricians:
Flickering lights, a sizzling sound when lights are switched on or off, plugs that spark, plugs that fit loosely in receptacles or lights that dim when appliances start.
These may signal a loose wiring connection, which can be a fire hazard.
Warmth in a wire, extension cord or fuse box. This may indicate a faulty or unsafe wiring connection, which could cause an overload and lead to fire.
A breaker that repeatedly trips, indicating an overloaded circuit.
A breaker that never trips, especially in an older home. That may be a sign that your wiring system lacks adequate electrical safeguards.
Also, make sure you know what kind of wiring winds through your home.
Copper is the ideal material. Pre-1940s knob-and-tube wiring and 1960s-era aluminum wiring are associated with greater fire risk.
Knob-and-tube systems feature porcelain knobs that anchor wires to studs and floor joists and insulated tubes that carry wires through walls and other obstructions.
Such systems have separate hot and neutral wires that run parallel to each other and dissipate heat into the air.
They can become a fire hazard if overburdened, improperly retrofitted or come in contact with insulation.
Problems with aluminum wire generally occur at connections, where exposed aluminum wire may rust, resisting current flow and generating heat.
Aluminum also expands and contracts in response to load and temperature changes differently than copper or other materials, so connections between aluminum and other metals can lead to problems that reduce conduction.
If you live in an older home and aren’t certain of its wiring type or safety status, schedule an inspection by a licensed, experienced electrician.
In the case of knob-and-tube systems, you may be able to upgrade one room at a time, especially during a remodeling.
With aluminum systems, an electrician may recommend total replacement with copper, or may replace connection points where aluminum wire is exposed to other metal types or air.
No matter what kind of wiring you have, experts recommend these do-it-yourself safety steps:
Trip GFCI receptacles monthly to be sure they’re working properly. The initials stand for “Ground Fault Circuit Interrupter.” GFCI receptacles have “test” and “reset” buttons. Press the test button to turn the receptacle off. The reset button turns it back on.
Make sure your home has enough smoke detectors. The U.S. Fire Administration suggests installing one in each sleeping area and on every level of the home. Test batteries regularly and replace once a year.
Inspect appliances and electronic equipment for old or broken plugs and cords. Replace anything that’s frayed, tattered or worn.
Leave repairs to an experienced electrician who is appropriately licensed, bonded and insured.
Ask also about whether parts, labor or both are under warranty.
Angie Hicks is the founder of Angie’s List, a resource for local consumer reviews; www.angieslist.com.