Fluorescent light fixtures are being replaced by LED fixtures at a pace not seen since knob-and-tube wiring was retired. The reasons are straightforward. LED fixtures use half the electricity, produce better light, work in cold temperatures, contain no mercury, and last 50,000 hours. A fluorescent fixture that still works is worth replacing anyway because the energy savings alone pay for the new fixture within a few years.
You have two options. Replace the entire fixture with a new LED fixture, which takes an hour and costs $30 to $100. Or convert the existing fluorescent fixture to LED tubes by bypassing the ballast, which takes 30 minutes and costs $15 to $40 in tubes. Here is how to do both, how to dispose of the old fluorescent tubes safely, and the one mistake that destroys an LED tube in seconds.
Safety First: Fluorescent Tubes Contain Mercury
Fluorescent tubes contain a small amount of mercury vapor. A broken tube releases mercury into the air and onto the floor. Handle tubes carefully when removing them. Do not drop them. Do not stack them where they can roll. Do not put them in the regular trash. Most hardware stores accept fluorescent tubes for recycling at no charge. Some municipalities require fluorescent tubes to be taken to a hazardous waste collection facility. Search your local disposal requirements before starting.
If a tube breaks during removal, open the windows and leave the room for 15 minutes. Do not vacuum the broken glass with a standard vacuum, which aerosolizes the mercury. Scoop up the glass and powder with stiff paper or cardboard. Wipe the area with a damp paper towel. Place all debris and cleaning materials in a sealed plastic bag or a glass jar. Take it to a hazardous waste facility. The small amount of mercury in a single tube is not a medical emergency, but it should be cleaned up properly.
Option One: Replace the Entire Fixture With LED
Turn off the power at the breaker. Verify the fixture is dead with a non-contact voltage tester. Touch the tester to the wires inside the fixture before touching them with your hands. Fluorescent fixtures are often wired through a switch. Confirm the switch is off and the breaker is off before working.
Remove the fluorescent tubes. Twist each tube 90 degrees until the pins align with the slots in the tombstones, the plastic sockets at each end. Slide the tube straight out. Set the tubes aside in a safe location where they will not roll or be knocked over.
Remove the old fixture. Most fluorescent fixtures are screwed to the ceiling or to a junction box. Remove the screws or bolts holding the fixture to the mounting surface. Lower the fixture enough to access the wiring. Disconnect the black hot wire, the white neutral wire, and the bare or green ground wire. The old fixture may have multiple wires from the ballast. You are disconnecting the supply wires that come from the ceiling, not the ballast wires that stay with the old fixture. Set the old fixture aside.
Install the new LED fixture. The new fixture comes with a mounting bracket that attaches to the junction box. Mount the bracket. Connect the supply wires to the fixture wires: black to black, white to white, ground to ground. Use wire nuts, not electrical tape. Wire nuts are the correct connector. Push the wires into the junction box. Mount the fixture to the bracket according to the manufacturer’s instructions. The fixture should sit flush against the ceiling with no gaps. Install the LED tubes or the integrated LED panel if the fixture does not use tubes. Turn the power back on and test.
Option Two: Convert the Existing Fixture to LED Tubes
Converting an existing fluorescent fixture to LED tubes is cheaper than replacing the entire fixture and takes less time. The conversion bypasses the ballast and wires the LED tubes directly to line voltage. The old fixture housing, tombstones, and reflector remain in place. Only the tubes and the wiring change.
There are two types of LED replacement tubes, and you must know which you are buying before you start. Type A tubes work with the existing ballast. You remove the old fluorescent tube and snap in the LED tube. No rewiring is required. This is the easiest option. The trade-off is that the ballast is still in the circuit and will eventually fail. When it does, you replace the ballast or convert to Type B at that time. Type A tubes cost $8 to $15 each.
Type B tubes require the ballast to be removed from the circuit. The tombstones are wired directly to line voltage. This is more work upfront but eliminates the ballast as a future failure point. Type B tubes are what this guide covers. They cost $6 to $12 each.
Turn off the power at the breaker. Remove the fluorescent tubes. Remove the ballast cover, which is the metal panel in the center of the fixture. Inside are the ballast and a tangle of wires connecting the ballast to the tombstones at each end of the fixture. Cut the wires as close to the ballast as possible. Leave as much wire length as you can connected to the tombstones. Remove the ballast and recycle it. Most hardware stores accept ballasts for recycling. Older ballasts manufactured before 1979 may contain polychlorinated biphenyls, or PCBs, which are hazardous waste. If the ballast is old, leaking black tar-like material, or has no manufacture date, handle it as hazardous waste. Most fluorescent fixtures installed after 1980 do not have PCB ballasts.
Rewire the tombstones. Type B LED tubes are powered from one end of the tube only. The pins at the other end are for mechanical support only. Identify which end of the fixture will be the powered end. All the tombstones at that end are wired together, hot wire to one side of each tombstone, neutral wire to the other side. The tombstones at the non-powered end are not connected to anything. They hold the tube in place mechanically. Follow the wiring diagram included with your LED tubes. Different brands have different wiring configurations. Some tubes are powered from one end. Some are powered from both ends. Some are powered from opposite pins at opposite ends. The diagram in the tube package is the authority.
After rewiring, install the LED tubes. For single-end powered tubes, the end marked line or with the power symbol goes into the powered tombstones. The other end goes into the unpowered tombstones. The tube will not light if it is installed backward. If it does not light, remove it, rotate it 180 degrees, and reinstall it. Reinstall the ballast cover. Turn the power back on and test.
Disposing of the Old Fluorescent Tubes
Do not put fluorescent tubes in the trash. Most Home Depot, Lowe’s, and Ace Hardware stores accept fluorescent tubes for recycling at no charge. The recycling bin is usually near the customer service desk or the exit. Call ahead to confirm your local store participates. Some municipalities require tubes to be taken to a household hazardous waste facility. A web search for fluorescent tube disposal near me returns local options. The mercury in one tube is small, but millions of tubes in landfills add up to a significant source of environmental mercury. Recycling is free and takes an extra stop on the way to the hardware store.
Troubleshooting LED Tube Problems
A Type B LED tube does not light. The most common cause is that the tube is installed backward. Remove it, rotate it 180 degrees, and reinstall. The second most common cause is that the tombstones are not wired correctly. Check the wiring diagram. Confirm that the powered end tombstones are connected to hot and neutral. Confirm that the non-powered end tombstones are not connected to anything. The third cause is a failed tombstone. The metal contacts inside the tombstone that grip the tube pins can corrode or lose tension over time. If one tube in a multi-tube fixture does not light but others do, the tombstone for that tube position may be bad. Replace the tombstone. They cost $2 to $5 each and snap or screw into the fixture housing.
An LED tube flickers. Flickering in a Type B tube means the tombstone connection is loose or the tube is not fully seated. Remove the tube and reinstall it firmly. Twist until the pins lock into the tombstone slots. Flickering in a Type A tube means the ballast is failing. Convert to Type B or replace the ballast.
Frequently Asked Questions
Is it better to convert to LED tubes or replace the whole fixture?
Replace the fixture if the existing fixture is old, yellowed, rusted, or unattractive. A new LED fixture looks better than a converted fluorescent fixture and costs only slightly more. Convert to LED tubes if the existing fixture is in good condition and hidden behind a lens or diffuser that hides the fixture housing. Garage and basement fixtures are good candidates for conversion. Kitchen and living area fixtures are better replaced. The additional cost of a new fixture is small compared to the aesthetic improvement.
What is a shunted tombstone, and why does it matter for LED tubes?
A shunted tombstone has an internal connection between the two pin sockets. Both pins in the tombstone are connected together electrically. A non-shunted tombstone has separate connections for each pin. Type B LED tubes that are single-end powered require non-shunted tombstones at the powered end because one pin receives hot and the other pin receives neutral. If you use shunted tombstones with single-end powered tubes, you create a dead short between hot and neutral when you install the tube. The breaker trips or the tube is destroyed. Check your tombstones before installing Type B tubes. Non-shunted tombstones have separate wire terminals for each pin. Shunted tombstones have a single terminal that connects to both pins. If you are unsure, replace the tombstones. They are cheap and the risk of a short is not worth the uncertainty.
My old fluorescent fixture hums. Will LED tubes fix the noise?
Yes. The humming is the magnetic ballast vibrating at 60 hertz. LED tubes that bypass the ballast eliminate the hum entirely because the ballast is removed from the circuit. Type A tubes that work with the existing ballast do not eliminate the hum because the ballast is still in use and still vibrating.
Last modified: June 14, 2026
