How to Tell If Fluorescent Bulbs Are Blown?

Cat McCabe

With the gradual phasing out of incandescent light bulbs, you'll see more compact fluorescent lamps (CFLs) on the market, along with light-emitting diode lamps (LEDs).

It's not as obvious as with an incandescent bulb when a compact fluorescent lamp burns out.

Also called compact fluorescent bulbs or energy-saving bulbs, CFLs contain trace amounts of mercury and must be disposed of carefully at hazardous waste or recycling centers. CFLs fit standard light bulb sockets but use less electricity than incandescent bulbs. Though CFLs can last for years, their electrodes and ballasts will eventually fail.


Very occasionally, a blown fluorescent bulb will emit an acrid odor and a little bit of smoke. Very rarely, the bulb will catch fire from the ballast, or socket end, failing. This can happen due to poor manufacturing quality or overheating of the bulb ballast due to improper use.


Don't use compact fluorescent bulbs in closed shade fixtures like glass or plastic globes, unless they are specifically rated for that use. Doing so will cause overheating, early failure and possibly fire.

  1. Flip the switch and wait a few seconds. If the fluorescent bulb fails to come on, turn the switch off. Try another light. If it comes on, you've ruled out a power failure in your area.

  2. Turn the fluorescent bulb clockwise to see if it's firmly seated in the socket. If it doesn't turn, you've ruled out a loose bulb.

  3. Check your circuit breaker box and confirm that the corresponding breaker is firmly in the "on" position. If it isn't, flip the breaker back to the "on" position. If it is, you've ruled out a problem in the circuit.

  4. Change out the fluorescent bulb with a new one. Turn the switch on. If the light comes on after a few seconds, you'll know the original bulb burned out.