How do I prevent the first bulb in a series of two LED ceiling bulbs from going out for ~30 seconds once every ~5 minutes.

Background Prior to a couple years ago, I had two working incandescent bulbs in the two BR30 ceiling light fixtures. I replaced them with a pair of CREE LED 100W-equivalent BR30 bulbs a couple years ago. I also obtained a new Lutron LED dimmer switch to go with them.

After installing the new bulbs, I quickly noticed that while the second bulb was working quite fine, the first bulb would go out for about 30 seconds, once every five minutes.

When weird things like this happen, it's usually due to an incompatibility between the bulbs and the dimmer switch. Recently, I've swapped out the bulbs for a pair of 75W-equiv Ecosmart LEDs, and they had the same problem. These bulbs are officially listed by Lutron as compatible with the dimmer. Finally, I tried a pair of 65W-equiv Phillips bulbs. They also had the issue.

I also bought another dimmer (of the same model) to see if maybe there was a defect in the first dimmer. It also has the issue. I plan to try a different name brand next (for reasons of form factor, my selection was limited, but I can change the form factor with more cost).

I'd be surprised if there was a transformer to make the bulbs low voltage, though it's a remote possibility.

What's causing the first bulb to go dark for ~30 seconds once per ~5 minutes? How do I fix it beyond just going back to incandescents?

  • How hot do these new bulbs get? Does the flakey on get any warmer than the other one? – brhans Jan 11 '20 at 0:40
  • There are thermal heat sensors in most recessed fixtures. Check to make sure they are attached correctly. Examine the fixture that's working to see how the sensors are supposed to be. you could just have a bad one. – JACK Jan 11 '20 at 1:07
  • The bulbs are cool enough to unscrew and replace, even after they've been on for hours. – interestedparty333 Jan 11 '20 at 2:16
  • That idea about a broken heat sensor could be it. – interestedparty333 Jan 11 '20 at 2:16
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    Can you screw one of those Edison-to-multioutlet adapters into the failing fixture then screw the lightbulb into that, and take voltmeter measurements at the adapter-outlet when the bulb goes dark? – ThreePhaseEel Jan 11 '20 at 5:01

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