Why Do Old Incandescent Christmas Lights Break So Often During Install and Takedown?
Because the filament inside an old incandescent bulb is fragile, and every year it sits in a box it gets more fragile. I learned this the hard way years ago, working a job for another company where the homeowner wanted their existing incandescent strands put back up instead of switching to something new. Bulbs started blowing during the install itself. More blew during takedown in January. And then, over the weeks in between, strands kept failing while nobody was even touching them, which meant driving back out to fix lights that had worked fine the day we hung them. It was not worth it for anyone, and I have not touched an old incandescent strand since.
What’s Actually Breaking Inside the Bulb
An incandescent bulb makes light by heating a thin tungsten filament until it glows, and that filament runs hot enough that it’s already thinning and weakening with every season of use. A filament in that condition is extremely sensitive to vibration and handling. Every time a strand gets pulled off a roofline, coiled up, shoved in a bin, hauled back out, and pulled taut again along the fascia, that’s exactly the kind of stress that snaps a weakened filament. The bulb that looked fine in the box in October is often one gentle handling away from being dead by November.
Why This Isn’t a Problem With LED
There’s no filament to break in the first place. LED bulbs make light with a solid-state diode instead of a heated wire, so there’s nothing fragile inside to snap when the strand gets coiled, uncoiled, and handled year after year. That’s the real reason I only install C9 and E15 LED bulbs, including the ones styled to look like classic warm incandescent bulbs. It’s not just that they use less power, it’s that they hold up to the actual physical abuse of being installed and taken down every single year without quietly dying in the box in between.
What This Means If You’ve Got Old Lights in Storage
If you’ve got a box of incandescent strands from a few years back, expect a chunk of those bulbs to be on their way out even if they worked fine last season. That’s not a sign anything was done wrong, it’s just how a fragile filament behaves after repeated handling. Every strand I put up is LED for exactly this reason, so a patron isn’t paying for a return trip mid-December because a bulb that looked fine in the driveway didn’t survive the ride up the ladder.
Frequently Asked Questions
Why do old incandescent Christmas lights break so easily?
The tungsten filament inside an incandescent bulb gets thinner and more brittle every season it’s used, which makes it extremely sensitive to vibration and handling. The physical stress of installing and taking down a strand is often enough to snap an already-weakened filament.
Do LED Christmas lights have the same problem?
No. LED bulbs use a solid-state diode instead of a heated filament, so there’s nothing fragile inside to break from the handling of a normal install and takedown cycle.
Should I reuse old incandescent Christmas lights I already own?
Expect a noticeable number of bulbs to fail during install, takedown, or randomly in between, even if the strand worked the season before. All the lights installed on My Hearthside jobs are LED, including styles made to look like classic incandescent bulbs, specifically to avoid this.
Want lights that are still working on the last night of the season instead of the first? You can get on my schedule now, or learn more about Christmas light installation and I’ll get you a free quote.