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We have a multistory apartment building where the hallway lights were switched from CFLs to LEDs. These lights are continuously on.

Originally the LEDs were SATCO 15W bulbs. These lasted about a year before beginning to flash/blink/flicker.

They have been replaced with FEIT Electric 10W bulbs. These now last less than 30 days before flickering.

The flashing goes at maybe 5Hz for a minute before going solid again before eventually dying.

There is no dimmer switch on the circuit (common cause of LED flicker). Am not sure what to check. Is there not enough resistance in the circuit?

(The 10W bulbs don’t last as long as the 15W bulbs.)

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  • Is the failure behavior identical across both brands of bulb?
    – Harper - Reinstate Monica
    Commented Nov 5, 2019 at 19:52
  • Good question. The flicker behavior is similar. I think the difference is that the 10W bulbs flicker for longer before dying (but their overall lifetime is less). They almost exhibit flicker due to what looks like an overheat condition. The flicker may cool them down and then they resume normal operation. Some will switch off entirely before switching back on.
    – Algis
    Commented Nov 5, 2019 at 19:59
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    Be interesting to do a teardown on both. I smell Chinese capacitors. Neither brand is particuarly well reputed.
    – Harper - Reinstate Monica
    Commented Nov 5, 2019 at 20:21
  • I suspect heat too. It'll make capacitors and semiconductors alike age and more quickly and accelerate failure of the product. Since the FEIT 10W bulbs routinely last fewer than 30 days, could you leave the glass cover off at the next lamp change and test whether the exposed lamps last longer?
    – Greg Hill
    Commented Nov 5, 2019 at 21:06
  • I would find a brand that is DLC listed, the DLC listing provides a 5 year warranty, the cheap imports might even offer a warranty but good luck on getting anything back, even after paying to ship the failed bulbs back.
    – Ed Beal
    Commented Nov 5, 2019 at 23:38

2 Answers 2

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You should check the packaging on the LED lamps. There are many that say not to use the LED bulbs inside enclosed lamp fixtures. The electronics built inside the base of LED bulbs that converts the AC mains voltage to that required for operation of the LEDs is often times not very tolerant of elevated temperatures. Even a low power 10W or 15W bulb inside a globe could build up heat to raise the temperature too much for the bulbs.

I highly suspect that there is a range of LED bulb quality that may very well make some more sensitive than others.

One thing you could try as an experiment would be to put new bulbs in a couple of the fixtures and leave the globes off for a few weeks to see if the last longer.

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Check the voltage at the lamps. If it is nominally 120 VAC, a bad neutral connection could cause variations well over that due to uneven splitting of the line voltage. The power supply in the LED might be overheating due to over-voltage.

Also check if there is heavy fiberglass insulation above the light fixture, preventing convection of heat from the lamps. A larger fixture, with a wider-diameter plate against the ceiling, might serve as a better heat sink.

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    I took a FLIR to a couple of the bulbs. They are at over 175F at the heat sink. This is for the 10watters. I’ll try to find if there are any 15watters left. Not sure if that is normal. The bulbs are oriented sideways, so that is more prone to heating. There is a reflective fiberglass matted insulation directly above. I may arrange for the glass cover to be not fully closed to leave an air pathway for cooling.
    – Algis
    Commented Nov 6, 2019 at 5:44
  • Also the circuit is very steady at 118v
    – Algis
    Commented Nov 6, 2019 at 14:04
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    Good use of FLIR, and nice photo! That extra ventilation can't hurt.
    – DrMoishe Pippik
    Commented Nov 6, 2019 at 18:58

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