Why Are My Christmas Lights Not Working?

Updated: Nov. 20, 2023

The good news is that there are only a few things can go wrong with holiday lights, and they're relatively easy to fix.

You planned. You prepared. You spent hours, if not days, hanging holiday lights around your house. So it can be pretty frustrating when it’s time to flip the switch on your holiday light show, only for it to fizzle.

Inspect and Test Lights Before Hanging Them

The best time to find and repair any issues with your holiday lights is when you unpack them.

To start, check the strand to make sure there aren’t any loose, missing or broken bulbs. After you unroll them, plug them in to any convenient outlet to make sure they’re all lighting up. If they’re working at that point, it’s time to start decorating.

Of course, you can also encounter problems with your lights well after they’ve been hung by the chimney with care, but many of the issues are the same.

Before getting frustrated and angrily hurling your lights or that plastic reindeer into the tree, take a deep breath. It’s relatively easy to fix your Christmas lights because there are only a handful of problems that affect them. Once you’ve diagnosed the issue, you can address it quickly and get back to sipping egg nog and enjoying the display you created.

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christmas tree lights bulb tester
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Bad Bulbs

Bulbs burn out, especially with light strands you’ve had for a few years.  One bad bulb can cause part or the entire strand of lights to stop working. That’s true of incandescent and LED lights.

If it’s just half the strand that’s out, often times the bad bulb is the first one that’s dark. If the entire strand is out, you’ll have to go through and check each bulb.

The easiest and fastest way to solve the latter problem is finding the trouble spot with a light tester. If you can’t get your hands on one, you’ll have to go through the strand and check each bulb. Light testers are relatively inexpensive, and they’re worth having because of the potential time saved.

Once you’ve found the bad bulb, just replace it. Check the light strand again and you should be on your way.

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lessoutlets_42962275_05 LED christmas lights
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Loose Bulbs

Light strands are in storage most of the year, and it often causes bulbs to come loose. It’s best to check for loose bulbs as you unpack light strands. If you find one, just click it back into place. Make sure you know these Christmas light dangers.

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Christmas lights fuse
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Blown Fuse

Most light strands have fuses hidden in a small compartment in the plug. To tell if it’s a bad fuse causing the problem, just pull them out and see if the filament is broken. If you can’t tell, try replacing each fuse one at a time with a new one and see if that does the trick. Don’t know how to fix a blown fuse? Learn how to change a fuse in Christmas lights.

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fix sensitive arc fault circuit breaker
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Tripper Breaker or Faulty Electrical Outlet

We take it for granted that whenever we plug something into a socket, the juice is there. But sometimes it’s not.

If you plug in a strand of lights and it doesn’t work, check the breaker box to make sure you haven’t blown a fuse. If that’s the case, just reset the breaker. If it happens again, you should find another outlet so you don’t overload the circuit.

Moisture in the outlet, lights or a cord can cause a breaker to trip, too, something to consider for outdoor lights especially. If you’re using extension cords, make sure they’re rated for outdoor use to handle the elements.

Waterproof covers for outdoor sockets help, too. You may have to use a different outlet, perhaps one tucked under the soffit and protected somewhat from rain and snow.

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hands holding broken Christmas lights
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Broken or Frayed Wires

Broken or fraying wires can also cause your strands to stop working. If that’s the case, don’t use those lights. Replace them immediately and recycle the old strand.

Using holiday lights safely should be at the top of your mind when decorating for the season, and exposed or fraying electrical wires are a fire hazard.