Finally Fix Christmas Light - Every Kind - With This Definitive Guide

Step 1: What Kind of Lights Do You Have?

Start by identifying your type of holiday lights. In most cases, you'll be making two determinations:

• Are my Christmas lights LED or incandescent?
• Are they indoor or outdoor lights?

Here's a quick overview of what you'll be tackling in each situation.

LED Christmas Lights

LED lights operate at a lower temperature than incandescent lights and last much longer. 

As desirable as LED bulbs are, they do come with their own issues. Most LED Christmas lights come as string lights — you're more likely to experience “sectional outages” (full sections of light strands going out) than individual bulb outages.

LED bulbs don't contain traditional filaments like incandescent bulbs. It's a bit harder to find the source of your light string issue — it could be prongs, sockets, or the LED diodes.

Incandescent Lights

If your Christmas lights are a bit older, you're likely dealing with incandescent lights. They're generally cheaper than LED lights, but they burn hotter. This leads to its own set of potential issues.

Incandescent holiday lights experience more stereotypical “Christmas light problems” — broken bulbs, burnt out filaments, and blown fuses.

Handle older incandescent lights with care. They're more likely to retain heat and shatter when handled, and we don't need your house looking like the set of Home Alone.

Indoor or Outdoor Lights? (Icicle Lights, Christmas Tree Lights, etc.)

We'll make this one quick — don't use indoor holiday lights outside. Ever.

If your lights aren't specifically designated for outdoor use, they're not safe to use outside. Outdoor Christmas lights and decorations are designed to resist wet weather and exposure to the elements.

Step 2: Diagnose Your Christmas Light Issue

We've answered our two primary questions about your broken Christmas lights (LED vs. incandescent, indoor vs. outdoor).

Now, let's figure out what's wrong with them before you pull your hair out.

Most Christmas lighting problems fall into 1 of 5 categories:

• Circuit issue. Check this first. Don't waste time replacing individual bulbs, only to find out the circuit isn't carrying power. 
• Blown fuse. Both incandescent and LED light strands generally carry cartridge fuses. If the cartridge fuse has a visible break in its glass or metal filament, this is likely your issue.
• Broken or exposed wire. Before you check individual bulbs, look at your light strand for exposed or broken wiring. If you find either, discard the strand to avoid major injury or electrocution. (And please unplug the strand before you check!)
• Burnt-out or faulty bulb. If your circuit is fine, fuses are intact and wiring is okay, look at individual bulbs. You'll check for a snug fit in each socket, signs of burnout, and proper compatibility between bulb and socket size and voltage rating.
• Multiple bulb outage. There could be multiple issues here. We'll address them all in Step 3. In the meantime, invest in an inexpensive Christmas tree light tester to speed up the process.

Now that we've diagnosed your specific light issue, let's get down to business and fix it.

Step 3: Troubleshooting Christmas Lights

You'll want the following equipment to properly test and fix Christmas lights:

• A bulb tester offers quick, effective diagnosis of individual bulbs. A basic one costs between $11 and $20 on Amazon. Quality bulb testing options like the Light Keeper Pro series cost between $20 and $40.
• A circuit testing device, like a continuity tester or multimeter, measures the connectivity and electrical current between two or more points. A serviceable multimeter costs between $10 and $30 and can be used outside the holiday season.
• Any extra replacement fuse or bulbs that came with the original products.

Fixing One Faulty Bulb

Here's a step-by-step guide to fix a single broken bulb on your holiday lights:

1. First, make sure the bulb is secured properly in its socket. 
2. If one bulb on your light strand isn't working, test each bulb around it to ensure proper function. Plug your lights in, then use a bulb tester on each surrounding bulb (and the problematic one).
3. Before replacing any bulbs, unplug the light strand completely.
4. If you have incandescent bulbs, check for signs of burned or darkened glass. This indicates a broken filament. You should take the bulb out of its socket and replace it like-for-like. Make sure the replacement bulb is the same color and size (C7 and C9 are popular sizes).
5. If the bulb looks fine, check the fuse. Replace a blown fuse with one of identical rating and size.

It's important to replace a faulty bulb quickly. Today's light strands have built-in shunts to direct electricity. When one bulb blows out, the excess electricity flows to the following bulb on the strand until it burns out as well.

If left unfixed, this is how one broken light bulb leads to a series of outages.

Fixing a Semi-Working Incandescent Light Strand

If your lights are partially out, follow these steps to fix a semi-working light strand.

1. Check for broken wiring first. If your light strand has electrical wires that are frayed or sticking out, unplug and discard the entire light strand immediately to ensure your safety.
2. Remove all non-working bulbs from the strand. Set them aside to avoid confusion with working bulbs.
3. Replace non-working bulbs with new replacement bulbs. If they work, your job is done! 
4. If incandescent replacement bulbs don't work, the problem lies with your fuses. 
5. Replace fuses as needed with ones of identical rating and size.

This should alleviate your partial incandescent outage issues. If it doesn't, refer to the “What if I Have an Entire Strand Outage?” section below.

Fixing LED Light and LED String Issues

LED light strings have additional features to consider.

1. Follow steps 1-3 of the incandescent light strand troubleshooting guide above.
2. If LED replacement bulbs don't work, the problem could lie with the fuses or LED diodes.
3. Test one fuse on a non-functioning light by replacing it with one of identical rating and size. If that light begins working, test the fuses on the other broken LED lights.
4. If the fuses are not an issue, check the LED diodes on your non-functioning lights. 
5. Use your multimeter to check the diode on one faulty LED light. Connect the multimeter's positive lead to the LED's positive lead — generally the longer of the two.
6. Next, connect the multimeter's negative lead to the LED's negative lead. If the diode is working properly, you should see at least a faint glow on your multimeter. 
7. If the multimeter doesn't glow, your diode(s) are the issue and should be replaced.
8. If the multimeter glows, your diodes are fine and you should double back to checking individual bulbs and sockets.

What if the Entire Strand is Out?

You've tested individual bulbs, fuses and diodes. None of them are the issue, but your entire light strand isn't working. Now what?

1. There's often a fuse built into the light strand's plug. Replace that fuse, then re-test the strand.
2. Take one more look at the entire length of your light string. Check closely for broken wires and disconnections.
3. It's a long shot, but check your circuit breaker. Better to be 100% sure before you buy replacement lights!
4. If your lights were exposed to moisture during storage, chances are they're not able to be saved.

If none of these steps work, it's time to purchase replacement Christmas lights. It's not ideal, but at least you know you've done everything you could.

Special Tips for Fixing Outdoor Lights

The same solutions in each section above apply to outdoor Christmas lights as well. There are extra steps and precautions to take when troubleshooting your outdoor light displays.

1. If your outdoor lights are touching any wet, damp or icy surface, disconnect them before any work begins.
2. Take the broken lights indoors and ensure they're fully free of moisture before troubleshooting.
3. If your outdoor lights are incandescent bulbs, follow the incandescent light guide above.
4. If your outdoor lights are LED strings — like icicle lights or modern light-up decorations — follow the LED light guide above.
5. Make sure any outdoor outlet is dry and fully functional before plugging your lights back in.

Step 4: Christmas Light Care

Take these steps to protect your holiday lighting during storage and handling. 

Proper Christmas Light Storage

• Plug your lights in one last time before packing them away. Make sure they're all in working order.
• Keep the original product boxes for storage. If not, buy large Tupperware containers.
• Wrap your light set loosely to avoid damaged bulbs and frayed wires. Keep replacement bulb sets with their corresponding light strands to find them easily.
• Store your lights properly. Don't push or jam your light strands down in storage containers — that's the fast track to light bulb breakage.
• Store your holiday lights in cool, dry areas. Keep them separate from other Christmas decorations, especially garlands and wood items.

Proper Christmas Light Handling

Avoid these 4 mistakes when handling your Christmas lights:

• Don’t pull from the cord. It's tempting to pull a light strand wire out of the wall from any distance. Don't do that. You can loosen bulbs from their sockets, fray internal wires, or damage the plug itself.
• Don't hold your Christmas tree lights by their bulbs. You can damage them internally. If they're older incandescent lights, they may break or burn your hand.
• Don’t handle bulbs with bare hands. When in doubt, put on a pair of work gloves when handling an incandescent bulb. They retain heat longer than LED bulbs.
• Don’t put direct pressure on LED lights. LED string lights are cooler to the touch, but avoid handling the lit sections roughly. You can damage the diodes.

Conclusion

The holidays aren't supposed to be stressful. We know that's easier said than done sometimes.

You can use this information to cross “fix Christmas lights” off your holiday to-do list this year. And that's a great start.

It's the same head-start we give all our HOMR members. Home management shouldn't be your second job — that's why we make it our only job.

Fall back in love with being home for the holidays. Let HOMR's 24/7 concierge team handle the rest.