We have had numerous situations involving LED flickering with dimmers. It can be that your dimmable bulbs (the box will say dimmable) are not high quality or have a problem, or you did not use dimmable LEDs or your dimmer switch is bad. You will have to replace either bulbs, switch, or both until you stop the flickering.

Oh, and yes the flickering usually happened after a period of time of being dimmed….say 30 minutes, I seriously doubt it is the wiring.

You need dimable leds and you also need to use led comptible dimmers with leds and incandescent compatible dimmers with incandescent. They are not compatible with each other.

The best dimmers by far are Lutron LED+ dimmers which have proven to be compatible with every type of LED bulb and fixture I have. In some cases, lights may remain on (barely) if the dimmer is set to its lowest setting. In this case get a dimmer with a switch such as the Diva or Skylark. For more settings flexibility, the Maestro has it.

As noted above, the LED bulbs and fixtures must be dimmable.