Troubleshooting Christmas Lights

It’s the most wonderful time of year! But in between party hosting and marshmallow toasting, Christmas lights can make displaying your holiday spirit a hassle. From finding that burnt out bulb to utilizing that trusted extension cord, we have solutions to those pesky and unforeseen holiday lighting quirks. 

Burnt Out Mini String Light Bulbs

One burnt out bulb can signal a major headache in your search to replace it. Incandescent string lights are notorious for this particular issue. Purchasing mini light strings that promise to stay lit when a bulb bites the dust is one way to make your hunt a little easier. However, you could be left in dark if several bulbs fail at once. Also if the shunt (i.e. the base part) of a bulb is damaged, there won’t be a complete circuit to keep the string lit and you will be looking for burn marks through the tiny colored glass. A mini light tester, like our Light Keeper Pro, will allow you find and correct bulb or voltage issues. Its Audible Voltage Detector easily scans and beeps for circuit interruptions at a bulb, broken wire, or poor contact where the voltage is blocked. You can also indulge your inner cowboy with its Quick Fix Trigger, which sends a harmless pulse of electricity through the circuit to find and fix a shunt that failed to energize, lighting the unlit section.

If you do have to replace an incandescent mini light bulb, check your string light packaging to determine which voltage your lights use. Most string lights require 2.5-volt or 3.5-volt bulbs. If you use 2.5-volt bulb on a light string rated to carry 3.5 volts, the higher electrical current will quickly burn out your new replacements. Using 2.5-volt bulbs on a 3.5 volt string will most likely result in a very dim string of lights. Unfortunately, there is no sure way to tell what voltage your spare bulbs are, except by keeping the packaging. When the replacing the bulbs doesn’t work, one final thing to check is the plug fuse. There is usually a sliding cover on the plug that allows you to open it up and replace the very small glass tubes inside. Many light string packages include spare fuses along with the spare bulbs.

String Light Cord and Plug Problems

Is a short cord keeping your Christmas masterpiece from lighting up the neighborhood? There’s an extension cord for that. Indoor extension cords keep the lights on your tree merry and bright, while outdoor extensions cords ensure your ladder-climbing is not in vain. Do you find yourself staring hopelessly at two plug ends with no prongs, wishing somehow they could connect? Even with stackable plugs, two female plug ends (i.e. prong-less) is a planning problem, not a lighting problem. Some people may try to find a double male (pronged) “adapter”. Those adapters are dangerous and illegal; they create a fire hazard and could shock someone or short out your lights if it comes into contact with any metal, even tinsel.

The easiest way to avoid both of these “uh-oh” moments is to measure first.  Start at the outlet you intend to use and measure every rafter, tree, and window you need your lights to cover. Also place a male plug end near your chosen outlet and make sure it stays there. For bottom-up decorators, lay out all of your lights male ends first. This keeps you from having two female plugs back-to-back. If you like to start at the top, put the female ends first at the top so you always have male plug end as you head towards the bottom. A few minutes of planning can save you hours of back-tracking.

Flickering LED String Lights

Yes, LEDs are brighter, glow with more vivid colors than their incandescent equivalents, and definitely use less energy. Less expensive or earlier versions of LED string lights may seem to flicker when lit. That’s because the LEDs are cycling on and off at 60 Hertz per second, which is just slow enough to be perceived by the human eye. Contemporary LED lights, like all of the sets of our site, include a rectifier near or inside the male plug end. These are known as fully rectified or “full wave” string lights and they operate at 120 Hertz per second, a power cycle that looks flicker-free.

Many of us like the rich colors of LEDs in some areas and the warm shimmer of incandescent lights for other places. It is very important that you NEVER connect LED string lights to incandescent string lights. Incandescent lights draw far more power than their LEDs cousins. As a result, the larger amount of power can blow the fuse in the LED lights.  Many LED strings come with spare fuses but save yourself some frustration and don’t mix and match those light strings.

Lighting Tip: Always keep your Christmas light packaging. You never know when you might need the information on it. At the very least, write it down somewhere.

How Many Light Strings Can I Put Together?

First, check the package for the maximum number of connections allowed. On average, incandescent string lights max out at about 3 sets of lights connected end to end, depending on the length of the string. Another benchmark is keeping your string lights’ power consumption to about 150 watts per circuit. Underwriter’s Laboratories (aka “UL” like “UL rating” and they decide this kind of guideline) recently adopted a new standard for the end-to-end connection of LED Christmas lights.  The new standard states that because of LEDs very low power consumption, they can be connected for up to 216 total watts on one 15 amp circuit.  That means LED string lights can sometimes manage anywhere from 20 to 100 connected sets at a time, just add up your wattage per string.

So be of good cheer while you climb that ladder with your new holiday lighting knowledge. If you have more Christmas decorating tips, lighting mysteries, or a good ol’ fashioned Christmas story, leave a comment in the area below. Find a vast amount of gorgeous lights, hilarious lighting mishaps, and informative lighting tips on our Facebook, Twitter, LinkedIn, or Pinterest. The 1000Bulbs.com staff wishes you a multitude of season’s greetings and a stress-free holiday.