How to Fix and Replace Christmas Lights

Squeeze another season out of your strings of lights!

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Burned-out holiday lights, even the cheap kind, are often fixable with a small investment in time and money. Here's how to diagnose and fix common problems.

Tools Required

  • Bulb tester

Materials Required

  • Light string fuses
  • Replacement light bulb

Troubleshooting Christmas Lights

Judging by our mail, it seems that most of us have experienced the frustration of uncooperative holiday lights. There’s a simple way to solve the problem, and here we’ll walk you through how to fix Christmas lights.

Plus, check out our homeowner’s guide for holiday lighting.

Project step-by-step (4)

Step 1

Christmas Light Repair: Check the Fuse

  • Christmas tree light repair is actually really simple.
  • First, slide back the plastic covering on the plug to check the Christmas light fuse.
    • Pro tip: Some Christmas light strings have more than one fuse, in which case they'll be next to each other.
  • Replace any blown Christmas light fuses.

Plus: Check out our recommendations for the best extension cords for outdoor Christmas lights displays.

christmas lights fuse diagram

Step 2

How to Test a Christmas Light Bulb: Option 1

  • Some Christmas light testers work by sliding each Christmas light bulb through a hole.
    • Pro tip: Usually, changing a problem bulb (or tightening it) will fix the entire strand.
  • Second, test the Christmas light bulbs with an inexpensive tester.
  • The Christmas light tester will indicate which bulbs are bad and need to be replaced.
    • Pro tip: For the Christmas light tester to work, the lights must be plugged into the electrical outlet correctly — the narrow "hot" blade into the narrow slot and the wide neutral blade into the wide slot.

christmas tree lights bulb tester

Step 3

How to Test a Christmas Light Bulb: Option 2

  • With other Christmas light testers, you simply touch each bulb. You can test an entire strand in a few minutes.
  • Sometimes you have two or more defective bulbs, so only identifying one bad bulb may not fix the problem.


christmas tree light bulb tester

Step 4

Christmas Light Safety and Storage

  • Keep in mind that inexpensive strings of lights aren't durable. So at the end of the holiday season, take down the lights with care.
    • Pro tip: Don't pull too hard on the wires. A loose bulb, broken socket or frayed wire is sometimes all it takes for the strand to malfunction.
  • After taking down the lights, plug them in before storing them to make sure they still work.
  • Then carefully wrap the lights in their original or similar containers, making sure the bulbs don't bang together. Proper storage is key to their continued success.
    • Pro tip: Wadding them up in a coil and stuffing them into a box will almost guarantee they won't work next year.
  • Also, be aware that most holiday light bulbs have short life expectancies, about 1,000 to 1,500 hours. This means the lights are designed to last one to three seasons, depending on your usage.
  • Newer style LED (light-emitting diode) lights are the exception. They can last 10 times longer than traditional lights.
  • To fix Christmas lights, the only tool you’ll need is a bulb tester.

Next, check out our handy holiday decorating tips here.

Christmas Light Safety and Storage