Originally Posted by
randyc
You can try moving the dimmer in question to the location that is working. If the problem moves with it, the dimmer is the problem. If you moved a working dimmer to the location that is not working and the flashing persisted, it is in the electrical system. Anything with a motor will generate noise on the electrical system. Refrigerators, HVAC, washers, etc. Microwaves are the worst culprit. I haven't seen the problem as much with newer flat screens, but TVs can also be major noise generators. LED drivers will multiply the noise exponentially. If you have 5 drivers on a circuit, the noise is multiplied 32 times! This is why you see quantity limits on a dimmer even though the wattage is well below the dimmer rating. Dimmers also compound the issue. You also need to make sure the neutrals are separated. Prior to arc-faults it was common to just tie all the neutrals together. That meant noise was distributed though out the entire system.