How to Replace a Fluorescent Light Ballast

Family HandymanFamily HandymanUpdated: Oct. 09, 2020

Stop fluorescent lights from flickering and humming with a new ballast.

Fluorescent lightsFamily Handyman
Next Project
Time

An hour or less

Complexity

Beginner

Cost

$51–100

Introduction

Replace the ballast when your fluorescent light flickers or makes an annoying hum. The repair will only take about 10 minutes.

Tools Required

  • 4-in-1 screwdriver
  • Nut driver
  • Wire stripper/cutter

Materials Required

  • New ballast
  • Wire connectors

When your fluorescent light flickers or makes a loud and annoying hum, a degrading ballast is the cause. The ballast takes in electricity and then regulates current to the bulbs. A typical ballast will generally last about 20 years, but cold environments and bad bulbs can decrease this lifespan significantly. You can get a new ballast at a hardware store or home center and install it in about 10 minutes. However, buying a ballast can be expensive, so consider pricing a brand-new fixture for comparison.

Replace the fluorescent light ballast in four steps.

Project step-by-step (4)

Step 1

Remove the Bulbs and Fluorescent Light Fixture Cover

  • Unplug the fixture or turn off the power at the main panel.
  • Remove the fluorescent ballast compartment cover to expose the internal wiring and ballast.
    • Note: The attachment method for ballast covers varies widely among manufacturers. It may be attached with nuts or clips or simply snapped into place.

Fluorescent lightsFamily Handyman

Step 2

Cut the Old Ballast Wiring

  • Snip the old fluorescent ballast wiring several inches from the end of the fluorescent ballast with side-cutting pliers or wire snips.
  • Cut all the wires connected to the fluorescent light ballast.
    • Note: There will be four to eight wires coming out of the ballast.