How to Troubleshoot Christmas Lights
When troubleshooting Christmas tree lights, whether it’s a bad bulb, blown fuse or a problem with the wiring, here are several ways to locate the problem.
Steps to troubleshoot Christmas lights:
- Make sure you unplug the lights before you do anything else.
- Check to see if the outlet that you’re using is working by plugging another device into it.
- Check each individual bulb to see if it’s loose or burnt out.
- Check for a blown fuse in the string.
- Look for signs of damage like corroded prongs or exposed wires.
Knowing how to troubleshoot Christmas lights can help you figure out if the string can be repaired or if it needs to be discarded.
If the wiring on a strand of string lights is exposed or damaged, don’t use the lights. Replace the strand.
Replacing a Holiday String Light Bulb
After troubleshooting and identifying the issue, use this section to learn how to repair Christmas tree lights. Replacing a string light bulb that won’t illuminate is an easy task. We’ll show you how to check Christmas lights; however, before checking your string lights, make sure the circuit breaker hasn’t tripped or a ground-fault circuit interrupter (GFCI) outlet doesn’t need to be reset. Both can keep string lights from working.
If the entire string of lights is out, the issue is most likely a blown fuse in the plug, a loose plug or the wiring. Unplug the lights to avoid the risk of electric shock and try replacing the fuse (see Replacing a Fuse in Holiday String Lights below).
These procedures are for incandescent Christmas lights; however, depending on your lights, they might work for certain light-emitting diode (LED) lights as well. Incandescent string lights differ from LED lights as they’re warm to the touch. LED Lights remain cool when placing your hand on them. We have general tips on how to repair Christmas tree lights below but always follow the light manufacturer’s instructions.
Locate the Bad Bulb
Start by plugging in your string lights and locating the bad bulb. Mark the bad bulb with painters tape or a binder clip.
Remove the Bulb
Unplug the lights and gently remove the bulb with a small flat head screwdriver. On some light strings, you first need to disconnect the bulb base from a tab on the side of the socket.
Remove the Plastic Cover
Straighten the metal filaments on the bulb and slide the base off of the bulb. In some cases, you might be able to insert a replacement light that includes the base and the bulb. If so, you can skip to Plug the String Back In, below.
Insert the New Bulb
With the old bulb removed, replace it with a new bulb and fold the metal filaments back over the plastic base.
Install the Light in the String
Insert the light into the open slot in the string, making sure it is secure. Attach the base to the tab on the socket, if necessary.
Plug the String Back In
Plug your lights back in and your new light should be working.
Many string lights come with a small bag of spare bulbs or bulbs already installed in bases. Tape this bag near the string’s plug to keep them handy if you need a replacement.
Replacing a Fuse in Holiday String Lights
Beyond replacing a burned-out bulb, a burned-out fuse can keep your string lights from working.
Check with your local waste management department for the proper procedure for disposing of string lights.
When Christmas Lights Aren’t Working
If the whole string of lights isn’t working and the outlet is okay, then you may have a burned-out fuse in your light string. Replacing fuses in Christmas lights isn’t difficult. Follow these next steps on how to change a fuse in Christmas lights.
Open the Fuse Cover
Before you begin, make sure your lights aren’t plugged in. Use a small screwdriver to slide the fuse box open. The fuse box is typically located on the string light plug.
Remove the Old Fuses
Pry the old fuses out of the plug with the screwdriver. Don’t break the glass. Install new fuses supplied by the manufacturer.
Check Your String Lights
Close the fuse cover and plug your lights back into the outlet to check if this solves your issue.
Ideas for Upgrading Your Christmas Tree Lights
Here are a few ways to upgrade the look of your Christmas tree using lights.
Switch to Energy-Efficient LED Christmas Lights
If you’re still using traditional incandescent bulbs to light your Christmas tree, it’s time to consider switching to LED lights. LED lights are durable, consume less electricity, have a longer lifespan than incandescent bulbs and emit very little heat.
Creative Tree Lighting Layouts
Everyone knows the traditional way of lighting string lights from the bottom up, but sometimes you want to skip tradition and try something new. This Christmas, show your creative side with these tips.
- Use fairy lights to wrap loosely around branches for a twinkly, dreamy look.
- Try clusters of micro-LED lights.
- Work your lights into the tree, starting right up against the trunk and working your way outward toward the tip of the branches. This adds depth to the tree.
- If your tree is in a corner and you typically don’t decorate the back, run lights in a zig-zag pattern across the front of the tree and the parts of the that are visible. This avoids wasting lighting at the back of the tree where no one will see it.
Play with Different Color Schemes
We’ve all seen Christmas trees where the lights are either all white or a cacophony of color, but why not try something different this year.
- The ombre effect starts with the darkest shade of light at the bottom and work your way up with the lightest shade at the top.
- Do a twist on the monochrome look: use different shades of one color (think red, but different hues, like cherry, rose, pink, salmon, etc.).
- Try a two-tone theme where you alternate strands of two colors, like red and green or white and gold.
Tips for Buying Christmas Tree Lights
- Ensure that all lights are Underwriters Laboratories (UL) listed.
- If you’re connecting two strands of lights, choose the same brand and type of lights.
- Consider purchasing energy-efficient LED (light-emitting diode) lights. Although they're more expensive, they're typically more efficient than traditional lights, shatter-resistant and cool to the touch.
- Buy an extra set or two of lights in case you need more.
Find out more with our Christmas Lights Buying Guide.
Fix or Upgrade Your Christmas Tree Lights with Lowes
A burned-out Christmas tree bulb can be a minor annoyance, especially if you have a long strand of lights to check. Once you find the burned-out bulb and replace it, you experience a brief moment of satisfaction. You’ve restored light to an entire strand and possibly saved it from being tossed in the recycling bin. Keep up the good work. Always troubleshoot Christmas lights before disposing of them.
When you’re ready to upgrade your tree with colorful lights for a festive theme, or you want to create a more delicate, magical effect with fairy lights or you just want to add more lights, we have a huge selection of lights to choose from. Shop online at Lowes.com for LED lights, mini lights and more. You can also stop by your local Lowe’s store and a friendly Lowe’s Red Vest associate can help you find the right Christmas tree lights and more.
Frequently Asked Questions
Customers regularly ask questions about fixing Christmas lights. Read on to find out about some of the most frequent questions.
How Do I Fix Half of My Christmas Lights That Are Out?
When you have half a strand of lights out, it means there’s a bad bulb in the strand or there’s a blown fuse. First, check the bulbs in the dark strand. It could be one bulb preventing the others from working. If that doesn’t work, then replace the fuse in the plug.
What Does a Blown Fuse in Christmas Lights Look Like?
It’ll look cloudy or black and the tiny wire inside may look broken or it might be missing. The fuses are in the plug. To see the difference, compare a blown fuse to a good one.
Can I Fix LED Christmas Lights the Same Way as Regular Ones?
It depends on the lights and the problem. LED lights are wired differently, and they don’t burn out the same way. Check the fuse and connections first. With some LED string lights, you can replace burned out bulbs and fuses. Follow the instructions for your lights.
What Tool Can I Use to Test Christmas Light Strands?
You can use a non-contact voltage tester or a Christmas light tester. They’ll help you find where the power stops flowing.
Why Do My Christmas Tree Lights Flicker or Blink Randomly?
Your lights may flicker because there’s a loose bulb or connection. Try gently wiggling each bulb to make sure it’s firmly in place. If the whole strand flickers, check the plug and the outlet. It could be a weak connection. If the plug is secure in the socket, it’s best to replace the strand, if possible. It’s typically not possible to replace light strands on prelit trees.