Check the wiring for loose connections, and check the light fixtures to make sure they are snugly installed.

Then call Lutron and Cree for advice. It might be a faulty bulb, might be a faulty dimmer.

Does it buzz all the time, or only when dimmed a lot?

I had something similar with my upstairs lights. I returned a few of the buzzing lights (because they didn't all do it) and bought more, and about 1/2 of those buzzed. It wasn't that important to me to do another return, and over time, I don't notice it as much. But, mine are in a hallway, the kitchen/main floor. Have you done any sleuthing to see if it is the light (all of them) or a specific light?

Thanks, lazy_gardens and kirkhall. The lights are all snugly installed. We did call Lutron and Cree after I posted this morning. (Thanks for the suggestion, laz_gardens.) According to Lutron, they test for compatibility, and unless they hear a significant hum or see flickering, they think that things are ok, and stated that LED's humming is a natural byproduct of the electricity cycling 120 times per second.

DH didn't ask Cree about the humming (I'm not sure why...), but he did ask them about their chart, and they said that if we noticed flickering or humming, then decrease the number of lights on the circuit until we no longer notice those characteristics occurring. DH was more concerned about whether running 12 lights on the circuit could cause premature failure of the lights or the switches, which he was told is not a concern since the switches are labeled capable of handling 150w of LED lighting. Our 12 lights fall in that range.

That's very interesting that some of your lights hummed and some didn't, Kirkhall. Are they the same brand we bought? DH can't hear the hum (he has some hearing loss and doesn't pick up on noises outside of his hearing range). I haven't climbed the ladder to check them up close. I could try that and see if I can figure out which ones are creating the sound. The noise is subtle, and when the household is active I don't pick up on it as much. The sound reminds me of the hum of fluorescent lights in a classroom.

No. We never did get the buzzing resolved and we moved on to other things. I usually use the LED’s at full force or nearly so. The buzz is worst at the lowest setting. When I want softer light, I use the incandescent lighting (We have an island chandelier and sconces by the sink) on dimmers instead. Honestly, the LED lights don’t go as dim as I’d like, and I prefer the warm glow of the dimmed incandescents and their ability to go really low. The LEDs are great for full force, leave no crumb unturned, time to amputate the turkey legs lighting.

This probably isn’t the solution you are looking for, but you might want to put table and floor lamps in the space that are ganged together and controlled by a dimmable switch. You could have an electrician wire outlets to do this.

Or, you can buy an aftermarket unit that lets you join multiple lights together that can be controlled with a dimmable remote. (This is what we’ve done in our living room and I’m very pleased with this solution.) Here’s an example from Amazon: Remote control light dimmers

Hope you can find a workable solution!

TL,

Which Lutron dimmers do you have? For some Lutron dimmers, if you reset the trim levels (the levels of dimming), you can eliminate the buzzing. I am surprised the buzzing is at the switch though. Usually the buzzing is at the lighting fixture.

TL,

curious if you resolved the buzzing at your switches? I found this thread since I now have the same situation...basement reno and the LEDs don't buzz but the dimmer switch, 2nd switch on the circuit as well as our electrical panel all buzz when the LEDs are turned on. We have 14 LEDs but are also not overloaded. The buzz is only there when the lights are on and connected to a dimmer. If we replace the dimmer with a regular switch the buzzing goes away. We've tried 4 or so different types of compatible dimmers so far and the switches still buzz. Our electrician can't hear it but at least is trying. His next suggestion was switching out all the lights with a different brand to see if that resolves it.

I have the same issue with using integrated LED Recessed Lights. I would strongly recommend the use of a ELV or MLV Dimmer rather than the CL dimmers that will dim the LED's but the LED circuitry require Low Voltage dimmers to reduce the buzzing. The lights I used were the Kodo Recessed lights from Home Depot. Great design and capability but even with an ELV dimmer, I can still hear a buzz. NOT AS BAD, but its still there. With 7.75 foot ceiling height in the kitchen, its annoying. I'm returning the lights unfortunately and hopefully I will find a replacement.

I just added a dimmer and wow buzz! after emailing both lutron and cree, I switched out my Lutron Dimmer that was listed for a listed Cooper Problem finally solved .

I have a kitchen ceiling LED fixture. There is buzzing with a dimmer. I called Kichler and they said I need to use Lutron ELV (low voltage) However the ELV requires a neutral line which my apartment doesn't have. My fixture is integrated so I can't just switch the bulbs. I would buy another fixture but don't know which one won't have buzzing. I thinking now I want to look at incandescent fixtures. Has anyone installed LED integrated fixture that doesn't require a ELV so it won't buzz?