The reason why the 3 way switch doesn't work properly is because the bulbs you are using are not dimmable. Sometimes you can buy dimmable bulbs and they will not work. Lutron has a list of supported bulbs on their website. Please make sure to use the bulbs they suggest. In this video you can see me operating the 3 way dimmable switch and it doesn't work with led bulbs and it does for the incandescent bulb I put in. I called lutron technical support and they helped me diagnose the problem immediately so I put this video here because I couldn't find any videos showing me what I needed to see.
