What's up with my lights? Replacing old bulbs with LED

In my kitchen I have four recessed flood lights. They are larger size, six inches or so in diameter. I also have two dimmer switches that control the lights.

I’ve always used the incandescent bulbs since I’ve owned the house, which has been 12 years now. When the CFL bulbs came out I tried them, but I could only get one to work, if I used more than one bulb they would either not work or would flicker.

I have just bought four LED bulbs to put in. They are all supposed to be ok to use with the dimmer switch. When I put all four in one of them took about two seconds to turn on. Then the bulbs started acting really strange. They would blink on and off. I replaced the one bulb that took longer to turn on with the incandescent bulb and the bulbs started going even crazier, they would flicker, turn on and off at different rates. It was like I was living in a horror movie.

I replaced another LED with the incandescent, so two of each, and the lights worked fine.

Any ideas of what is going on here? Is it the dimmer switch? I don’t use it and have been thinking of replacing them. Is it the housing or maybe the wiring itself?

LED/CFL bulbs need different dimmers. Lutron makes several types.

Older dimmers need a minimum load, and a consistent one, to work right. If you switch to LEDs, you have to switch to LED-compatible dimmers as well.

The trick, as you found, is to use one incandescent to give that steady load. I have a big chandelier in the dining room, and five of the bulbs are LED and the sixth is an incandescent. Works perfectly, although obviously I am losing a little bit of efficiency through that one bulb. (OTOH, the lamp is rarely much past half-brightness.)

LED bulbs draw power more like an electronic device than a resistive load, and most dimmers are optimized for a resistive/AC cycle operation that confuses the LED bulbs’ power supply.

Yeah, the dimmer makes a big difference. I put LEDs in the bedroom with one of those old cheap knob-type dimmers and it was terrible. The LED dimmed in stages instead of smoothly, then abruptly turned off at about half brightness.

But the ones I put in the kitchen work beautifully on a newer dimmer. It is still about 10 years old but was a top of the line at that time with a slide switch and an on//off push button.

Dennis

Also, not all supposedly dimmable LEDs work well with dimmers that supposedly work with dimmable LEDs. You might find a compatibility chart for the dimmer and/or LEDs that you’re using.

Thanks everyone, I replaced my switches last night and it seemed to have helped. The lights no longer flicker with all of them being LEDs. The person who installed them didn’t seem to have done that great of a job either. The ground wire came off on one of the switches when I pulled the old switch out.