LED bulbs aren't bulbs in the same sense as incandescent or halogen ones, and they are a little more complex. What this means for you, annoyed as you are by flickering LED track lights, is that you might have to do some detective work to find the problem. Of course, if a bulb is flickering, it's always possible that something is wrong with it. You can fix the flicker by changing the bulb. If that doesn't work, it's time to start the investigation.
How LED Bulbs Work
An LED bulb is a collection of circuit elements called diodes, whose usual purpose is to rectify alternating current into direct current. Those diodes in an LED bulb happen to emit light in the process. They are more sensitive to incoming voltage than conventional bulbs, and low voltage flickering light bulbs are commonly a result of unstable input voltage.
Check for Loose Connections
MR16 LED bulbs have a multifaceted background that reflects the light generated by the LED. These bulbs also often have GU10 bases, which consist of a pair of pins that must clamp securely into the "tombstone," which is another word for the socket. The first thing to do is to check for loose bulbs. Grasp each flickering bulb, give it a slight push and try turning it to the right. If it's already tight, it won't move, so try the next one.
Next, turn off the power to the circuit, remove the terminal panel on the track lighting fixture and check the wiring. If any of the wire nuts are loose, the wires are probably not in complete contact. That's a possible cause of intermittent flickering LED lights. Tighten loose wire nuts by screwing them clockwise.
Finally, check the connections at the switch by turning off the breaker, removing the switch cover and inspecting the wire connections. The switch could also be at fault, and you can test that with a voltmeter while the switch is on. Turn the breaker back on, touch one voltmeter lead to ground and the other to the switch output terminal and watch the meter. It should hold steady somewhere between 100 and 120 volts, and if it fluctuates, it's probably bad, so try replacing it.
Dimmer Causes LED Bulb Flicker
If you use a dimmer switch to control the light fixture, it could be causing the flicker even if it's operating normally, says Lamp HQ. The problem could be that you're using the wrong kind of bulbs or the dimmer isn't the right type for LED bulbs.
Many contemporary LED bulbs are dimmable, but because LEDs last so long, it's possible the ones in your fixture were manufactured before dimmable bulbs were common. If that's true, the repair strategy is easy: replace the bulbs with dimmable ones.
The track fixture may already have dimmable bulbs, and if they flicker, it could be because the dimmer isn't designed to work with LED fixtures. The minimum load that older dimmers need to function is often too low to fully energize LED bulbs. Replace the dimmer with an appropriate one.
Intermittently Flickering LED Lights
If you can't trace the cause of the LED bulb flicker to the track fixture or the light circuit, you might have a systemic wiring problem that needs to be addressed by an electrician. Pay attention to when the flickering occurs and note whether it happens when someone in the house turns on a large appliance or one, such as the refrigerator, cycles on by itself. If you see a correlation, there's a problem in the electrical panel or your home's wiring.
The cause of the flicker could be the signal coming from the power line, although this is rare. However, it's worth asking your neighbors if they are having similar issues. If so, call the power company.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.