There are only a few things as headache-inducing as getting ready to be productive, only to be interrupted by a fluorescent light that won’t turn on or that starts to flicker.
What’s worse—a fluorescent light that doesn’t work isn’t just a nuisance, it can be dangerous. Approximately 35,000 house fires per year are caused by “electrical distribution and lighting equipment.”
If you find your fluorescent light won’t turn on sometimes, there could be a variety of reasons why.
It could be as simple as needing to replace the bulb or plug the light itself in; or, it could be something more serious, such as a blown fuse or a damaged/dying starter.
In this article, we’ll help you troubleshoot the issue you may be having with your fluorescent light so you can solve it once and for all.
My Fluorescent Light Won’t Turn on Sometimes: What’s The Problem?
While there is technically the chance something abnormal is causing your fluorescent lighting issues, there are some common problems (that are easy to solve) you should check first.
1. The Light is Not Plugged in
I know, you hate to hear it. But it’s true, the first step to troubleshooting any electric device is making sure it is plugged in.
If that is your problem—congratulations, all you have to do is plug it in! And don’t worry, we’ve all been there.
If you are plugging your light into a surge protector, make sure you have it turned on! If the power is switched off at the circuit breaker, unplug electronics before switching it back on.
Keep reading to find out what you should do if your circuit breaker is being tripped frequently.
If your fluorescent light fixture is tied to a switch on the wall, you may also check problems with your light switch not working properly.
2. It is Time to Replace the Bulb
Similar to making sure the light is plugged in, it is worth checking that the light bulb is screwed in all the way.
However, if your fluorescent light bulb is screwed in, it is time to investigate whether it has any other problems.
Maybe your fluorescent light is old, or maybe the light bulb is defective. Regardless, a bad bulb is a bad bulb.
Signs of a dying fluorescent light bulb include:
- The bulb is dim when first turned on
- The bulb randomly flickers or shuts off
- The light has changed colors
- The bulb is discolored or black, especially towards the ends
Since a dead fluorescent bulb can’t be repaired, the only way to fix a fluorescent light with a dead bulb is to go buy a new one.
Some places fluorescent light bulbs can be purchased include Walmart, Lowes, and Home Depot. If you don’t feel like visiting a box store, you can buy them online too.
When you remove the light bulb, make sure to check if the light fixture socket is corroded. In tropical or subtropical places, fluorescent lights sometimes won’t turn on in high humidity due to corrosion.
Friendly reminder—in order to avoid injury, do not stand on unstable surfaces while checking light fixtures, and make sure the power is off so you do not accidentally electrocute yourself!
While you are checking your lightbulb, you may also want to check your starter. We will talk more about that in the next section.
3. A Damaged or Dying Starter
It can be difficult to tell whether the light bulb or starter is the root of your problems.
If you checked the light bulb as recommended in the previous section and did not find any obvious problems, then your problem may be the starter.
Since both are cheap to replace, if you do decide to replace one (either the light bulb or starter) we recommend replacing both to ensure you have fully addressed the issue.
Additionally, it does not hurt to keep spare fluorescent light bulbs and starters in a cool, dry place to avoid having to do a late-night Walmart run.
After all, an ounce of percent is worth a pound of cure. In the video below, you can see how to replace fluorescent tube bulbs and starters.
4. A Bad Ballast
First of all, what is a ballast? In fluorescent lights, the ballast controls how much voltage the light bulb gets.
Ballasts go bad due to age, damage, or loose internal wires. Similar to fluorescent light bulbs and starters, they can’t really be repaired, just replaced.
Signs of a bad ballast in fluorescent lights are:
- a buzzing sound
- dim light (either when first turned on or continuously)
- changing light colors
- burns marks
- water damage
- leaking oil
Unfortunately, fluorescent ballasts are not one-size-fits-all and replacing them can cost as much as just buying a new fixture.
Unusual wear-and-tear or damage notwithstanding, ballasts for fluorescent lights should last at least a decade. As a result, it is worth doing a cost comparison—especially if the fixture is relatively new.
As a personal tip, I always recommend using electronics the day of purchase, so that way you can return as soon as possible, if needed.
However, if you are determined to replace the ballast on your own, you can find them at pretty much any hardware. The entire process should only take about 10 minutes.
5. Blown Fuse or a Tripped Circuit Breaker
The final item on our list addresses the more complicated reasons for fluorescent lights that are flickering or not turning on.
The general cause of a blown fuse is that too many appliances are plugged in and it overwhelms the circuits.
This is more likely to happen if you have an outdated fuse box instead of a circuit breaker. Circuit breakers are tripped when something short circuits.
Short circuits can be caused by:
- Old, damaged, or loose wires/screws/electrical outlets
- Incorrect fuse was installed
- Too many devices are plugged in
- Outdated fuse panel
- Electrical service needs to be upgraded
We strongly recommend calling a licensed electrician if you suspect any of these issues. Do not try to DIY your electrical problems, as it is very dangerous.
If you live in a short-term rental, it may be unrealistic for you to call an electrician. If that is the case follow my electrical safety tips below, and avoid plugging in too many electronics at once.
To make your life easier, you can find a verified Better Business Bureau (BBB) electrician near you here.
Some Last-Minute Electrical Safety Pro-tips:
- While plugging in your light, make sure the area is free of any debris or exposed wires.
- You should consider switching outlets if you find the plug hanging loosely from the socket.
- Cover electrical sockets and keep wires where children and pets cannot reach.
- Protect your electronics by using surge protectors—just be careful not to plug too many high-demanding electronics into one strip.
Bonus points if you get a surge protector where you can turn off each individual socket.
In summary, if your fluorescent light won’t turn on sometimes, there are many potential reasons.
In order from easiest to most difficult to solve, the reasons are: the light isn’t plugged in, the power isn’t on, the light bulb and/or starter needs to be replaced, the ballast is old or damaged, or you have electrical issues outside of the light fixture.
Some problems are more likely to be recurring (like corrosion and water damage) if you have fluorescent lights in a high humidity climate.
While figuring out your electrical issues, please remember to be safe.
While you do fluorescent light troubleshooting, make sure the power is off, you are standing on a stable surface, and that you leave complicated issues to professional electricians.