Why are my lights flickering?

Florida Power & Light’s (FPL) troubleshooting starts by asking whether your neighbors are affected.^⁠[8]

1. Switch it off and let it cool

   Turn the light off (for a lamp, unplug it too) and wait a few minutes, so the bulb is cool before you touch it.^⁠[3,9]

2. Tighten the bulb

   Screw it in snugly. The Electrical Safety Foundation International (ESFI) notes that a loose bulb can overheat.^⁠[4]

3. Try a bulb you know works

   Use one with the wattage the fixture calls for, because a higher-wattage bulb can overheat the fixture or its wiring.^⁠[10]

If it’s a lamp, check that the plug fits snugly in the outlet and the cord isn’t frayed or cracked. Stop using a damaged cord, and report an outlet that won’t hold a plug.^⁠[10]

If a good bulb still flickers, the fault is in the fixture, the switch or the wiring. The U.S. Consumer Product Safety Commission (CPSC) says finding and repairing wiring problems is a job for a qualified electrician.^⁠[11] If the light is on a dimmer, read the next section first.

An LED can flicker when it isn’t matched to the dimmer switch it’s on. To dim smoothly, it needs a driver (the electronics that power it) that’s made to work with a dimmer. Without one, the Department of Energy says, an LED can flicker as much as 100%, from fully on to fully off.^⁠[1]

Check that the package says “dimmable.” Even so, not every dimmable bulb works well with every dimmer. ENERGY STAR’s 2017 dimming guide suggests trying a different bulb or changing the switch when a pair doesn’t work.^⁠[17]

A circuit connects lights and outlets to a breaker in your electrical panel. ESFI lists flickering lights as a warning sign of an overloaded circuit.^⁠[19]

• The circuit is overloaded. ESFI lists flickering, blinking or dimming lights first among its warning signs of an overloaded circuit.^⁠[19]
• A connection is loose. CPSC says a loose screw holding a wire, or a worn-out switch, can lead to arcing (electricity jumping a gap), overheating or a fire, and lists dim or flickering lights among the warning signs.^⁠[10,11]

If you rent, report flickering lights to your landlord or property manager.^⁠[6]

The national voltage standard that utilities follow doesn’t cover short dips from motors starting.^⁠[20]

A dip that lasts, gets worse or reaches the whole home is different. ESFI lists lights that brighten or dim when other appliances turn on or off as a warning sign. It says to have an electrician inspect your home as soon as possible.^⁠[18]

• Plug heaters and big appliances straight into a wall outlet, not an extension cord or power strip, and use one heat-producing appliance per outlet.^⁠[4,19]
• Keep computers and TVs off circuits shared with refrigerators, washers, dryers and microwaves, as DTE Energy, a Michigan utility, suggests.^⁠[12]

The national standard utilities follow, ANSI C84.1, aims to keep a 120-volt home between 114 and 126 volts most of the time.^⁠[20,21] FPL says swings bigger than that may make your lights dim or brighten.^⁠[22]

Flicker when the wind blows can come from a bad contact where the utility’s line meets the cable into your home, CPSC says.^⁠[11]

When the neighbors’ lights flicker too, the cause is likely out on the utility’s lines. Florida’s utility regulator says these brief interruptions usually last no longer than a few seconds. Their most common causes are lightning, fallen branches and animals.^⁠[16]

LG&E and KU, two Kentucky utilities, say their equipment cuts the power for a moment to clear a branch safely. They ask you to let them know if flickering happens often or lasts longer.^⁠[2] A full outage is a different problem: here’s what causes outages on the grid, and who fixes them.

Flickering lights can be a sign of a wiring problem that could start a fire. That’s why ESFI, CPSC and the National Fire Protection Association (NFPA) all treat them as a reason to get your wiring checked.^⁠[5,6,7]

Fires involving wiring, outlets, switches, cords and lighting averaged 31,650 a year in US homes from 2019 to 2023, NFPA estimates. They caused 430 deaths a year.^⁠[23] In NFPA’s earlier study of 2015 to 2019, arcing was the heat source in 73% of these fires.^⁠[24]

Homes wired or rewired between 1965 and the mid-1970s may have aluminum wiring. CPSC lists flickering lights among its warning signs and says to have a qualified electrician find the cause, not to do it yourself.^⁠[25] If you rent, tell your landlord or property manager about the flickering.^⁠[6]

Don’t take the cover off a switch, outlet, fixture or panel to look for the cause. CPSC says to have a qualified electrician find it instead.^⁠[11]

Your utility looks after its own lines, and FPL says electricians aren’t allowed to work on its lines from the pole to your house.^⁠[22] Where its part ends and yours begins depends on the utility. At Con Edison, the service wire and meter are the utility’s, but the equipment on the side of the house belongs to the property owner.^⁠[27]

Even if you buy your electricity from a separate supplier, your local utility, the company that delivers the power, still handles the lines.^⁠[30] In Ohio, for example, the state’s utility commission says to call your local utility in an outage, even if you’ve switched suppliers.^⁠[31]

In much of Texas, you buy electricity from a retail provider you choose, but your local utility still delivers it to your meter.^⁠[30] Examples include Oncor and CenterPoint; the state’s utility commission lists each one’s outage number.^⁠[30,32] You can find your utility’s outage and emergency line in our utility guides.

In a master-metered building, one meter covers every unit and the building holds the utility account. If that’s your setup, start with your landlord or property manager. Here’s how to tell whether your unit has its own meter.

Flickering lights are a job for an electrician, your landlord or your utility. We can help with the account side: connect your electricity account, and we’ll track your usage and bills and look for savings in the background. It’s free and needs no hardware.