Question: How many people does it take to change a Christmas light bulb?
Answer: Just one. A person who knows what they’re doing.
Here’s the lowdown on Christmas light bulbs to save you from a festive headache this year.
Know Your Bulbs
Do you know your C7s from your LEDs? If not, here’s what you need to know.
C7 & C9 Lights
These larger, more robust 5 to 10 watt bulbs have been around for a while and are mainly used as outdoor lights.
Because of the high levels of heat these bulbs produce, it isn’t advisable to use them indoors.
A big advantage of the old-fashioned C7 & C9 bulbs, is that they’re wired parallel to each other, meaning that if one bulb goes it won’t effect any of the others.
Mini Lights
Invented in the 1970s, Mini Lights remain the most popular type of bulbs for festive decorations, both inside and outside the home.
They use much smaller bulbs than C7s and C9s (only 2.5 watts), making them cheaper to run and more environmentally friendly.
Unfortunately, the original Mini Lights were wired in a series, meaning that when one bulb blew or came loose, the whole lot went out. However, later versions use what’s known as an ‘internal shunt’ to ensure the problem no longer occurs.
LED Lights
Light Emitting Diodes or LEDs are the modern way to light up your home at Christmas.
Despite only being tiny, LED Christmas lights are built strong and can last well in excess of 20 years.
They also use far less electricity than Mini Lights, making them even more environmentally and economically friendly.
Locate the Problem
If one bulb goes out out on your Christmas lights, it’s easy enough to buy a replacement bulb and fix the problem.
However, if all the lights have gone out, there’s a couple of things that could be causing the issue.
Check the Fuse
Checking the fuse hasn’t blown is a good idea. You can do this by carefully unscrewing the plug and pulling out the fuse.

Examine the inside and if you see the small thin wire connecting the two ends is broken then the fuse is blown. Similarly if it a small tubular bulb fuse you can see if the filament inside is connected or broken.
It’s worth noting that many sets of Christmas lights include a spare fuse, as this is a common problem, especially when multiple strings of lights have been connected together.
Check the Connections
As previously mentioned, some Christmas lights are wired in a series, meaning that if one bulb is loose or blown, then none of the lights will come on.
Turn the power off, ensure all of the bulbs are firmly in place and try switching them on again. You might find that one loose bulb was causing the problem.
If one of the bulbs has blown, then the problem is slightly more difficult to solve. You need to locate the faulty bulb, which is difficult to do without being able to turn the lights on. Fortunately, you can buy a Christmas light tester, which is purpose-built for this one job.
Buying Replacement Bulbs
Hunting down the replacement bulbs you need for your Christmas lights can be an arduous task. Fortunately, Snowtime have a fantastic range of Spare Bulbs to save you from traipsing around.
Make sure you check the box that your Christmas lights came in, as spares are often supplied, which might well save you the added expense. The packaging should also tell you exactly what kind of bulbs you need to get, which saves you the job of having to find out.
But if you no longer have the original box or can’t find the information, fear not.
Most sets of 10 mini lights require 12 volt replacement bulbs to light up properly. Sets of 20 require 6 volt bulbs and sets of 35 and up need 2.5 volts. Make sure you have one of the original bulbs with you, so you can find a replacement that’s the correct style and size.
Changing a Christmas Light Bulb
Like anything to do with electricity, make sure you take special care when changing a bulb on your Christmas lights. Here’s a step by step:
- Turn the power off and unplug your Christmas lights.
- Grip the bulb by it’s plastic base and carefully maneuver it out of it’s socket.
- You should now be able to separate the bulb from it’s base by bending the wire at the bottom of the bulb, until they’re straight.
- Now slip the replacement bulb into the base and bend the wire at the bottom to fasten it in place.
- Finally, reinsert the base with the new bulb into the socket, making sure the wires line up with the contacts.







{ 10 comments… read them below or add one }
← Previous Comments
am looking for replacement white tipped bulb for curtain window chrustmas lights 10v-0.13a 1.3w clear
After reading this helpful guide, and the part that says
“Hunting down the replacement bulbs you need for your Christmas lights can be an arduous task. Fortunately, Dobbies have a fantastic range of replacement light bulbs to save you from traipsing around”
I just popped down to my local Dobbies in Nuneaton Warks, to look a the spare bulbs, only to be told by one of there members of staff that they don’t do spare bulbs!!! :s
I have a set of christmas tree lights, for which I am trying to get spare bulbs. The colour is orange, there are 40 lights, and I believe the code is P1. I would like some normal spares, and also some fuse lights with the white caps. Can you help?
I am looking for replacement bulbs for Christmas outdoor lights. The bulbs are small, round small edison screw 14w 5v. Are you able to supply?
Hi Frederick – thanks for your query. While we do sell some replacement Christmas light bulbs, unfortunately we are unable to supply the type you’ve requested. Please visit Dobbies.com for more information.
← Previous Comments