I have several lighted ceiling fans of the same model wired with separate, non-dimming, wall switches for the fan and light. The lights inside may be LEDs, but I haven't disassembled them yet to confirm this.

For one of the fans, switching on the fan at the wall causes the light to briefly go out, for maybe a tenth of a second, then come back on.

This strikes me as very strange. I thought maybe the inrush current for the fan was dropping the voltage enough that an LED light might turn off and then recover, but this seems unlikely.

I thought maybe there was a loose connection in the switch that would move when the switch was operated, but tapping/manipulating the switch didn't seem to have the same effect.

Any thoughts before I de-energize the circuit and start testing everything?

  • 3
    Try swapping out the bulbs with another fan and see if the problem follows the bulbs or stays with the fan.
    – JACK
    Jan 7, 2020 at 17:27
  • A loose connection in the fan connections may also be the issue, the higher current draw causing a voltage drop once the fan is up to speed the voltage returns and the lamp starts working , sounds like a led or cfl type of driver issue caused by a bad connection.
    – Ed Beal
    Jan 7, 2020 at 17:43
  • Do the fans have separate wires from the switch box for the fan and the light kit, or are they both controlled using a ceiling module? Jan 8, 2020 at 0:57
  • @ThreePhaseEel Separate wires, happily. Jan 8, 2020 at 13:25
  • @JACK It looks like the lighting unit on the fan is a self-contained LED module. I couldn't devote a lot of time to it yesterday, but it doesn't have any obvious ways to open it. I should probably be able to swap the entire lighting unit with another and report back. Jan 8, 2020 at 13:27

2 Answers 2


This isn't really an answer, but I thought I'd close the loop.

Changing the bulb to a different brand of LED bulb causes the flicker to stop.

This doesn't explain why the flicker is there to begin with, but all of the installed fans of the same model exhibit this behavior.

Ideally, I would investigate further, but time is limited.

  • It's an "answer" in that it identifies the problem and a way to solve it, even if it's not ideal. Please be sure to click the check mark so people with a similar problem in the future know that this one has a workable solution.
    – FreeMan
    Jun 26, 2020 at 16:09
  • @FreeMan As dirty as it feels to accept my own answer, I have complied. Jun 27, 2020 at 14:33
  • Don't sweat it! Self-answered and accepted are perfectly legitimate at all SE sites. It's one of the things that makes this Q&A site different!
    – FreeMan
    Jun 27, 2020 at 15:03

The flickering problem above was due to replacing bulb(s) with higher than rated wattage (this info. is on the light socket and usually a sticker near the socket). New bulbs also need to be LED or CFL in addition to max wattage (typically 14w max.).

  • Since the OP didn't make any mention at all of the wattage capacity of the light fixtures, nor of the wattage requirements of any of the bulbs, this is a pretty bold statement to make. Do you have any references that can support this? If so, edit them in, as that would go a long way toward making this a good and useful answer. Without that, it's bordering on "some guy on the internet said...".
    – FreeMan
    Nov 30, 2022 at 12:38

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