Possessed Lightbulbs

[fossyant]

Yesterday, I received a number of messages from my daughter about the bathroom lightbulb going bonkers. I wasn't able to reply at the time as I was in meetings, so MrsF had answered.

Turns out the light bulb started flashing when daughter went for a shower. She went to turn it off, and it was actually switched off.

Turned on, light bulb working as normal, switched off, started flashing. Anyway, some time later it stopped.

I explained that LED bulbs, when starting to fail, do weird stuff. The bulb has been in the fitting for some years.

Get home, check fitting, OK, put in new bulb, no weird behaviour.

 

[SpokeyDokey]

Yesterday, I received a number of messages from my daughter about the bathroom lightbulb going bonkers. I wasn't able to reply at the time as I was in meetings, so MrsF had answered.

Turns out the light bulb started flashing when daughter went for a shower. She went to turn it off, and it was actually switched off.

Turned on, light bulb working as normal, switched off, started flashing. Anyway, some time later it stopped.

I explained that LED bulbs, when starting to fail, do weird stuff. The bulb has been in the fitting for some years.

Get home, check fitting, OK, put in new bulb, no weird behaviour.

Spooky things!

 

[fossyant]

I had visions of having to change the light fitting, but it was fine. I've had LED bulbs do weird stuff before fortunately.

Or it actually was possessed ?

 

[si_c]

Might be worth checking that there is no leakage on the circuit - I'm not familiar enough with LED bulbs to know why one might start flickering with no power - but I'd assume that with no power there should be no light.

I'd want to check that there isn't a live neutral somewhere.

 

[T4tomo]

Sounds like a loose wire in the switch somewhere (or the switch in out wires in the fitting) in that's its not properly off when it should off and the circuit is being completed.

 

[PapaZita]

Agree with the suggestion that leakage could be the cause. LED bulbs have a little power supply circuit inside. A tiny amount of leakage current can cause this to charge gradually up to the point that the bulb is able to light. When the bulb lights there’s not enough current to sustain it, so it goes out again. This repeats causing the flashing.

Particularly since it’s in a bathroom, check for any moisture where it shouldn’t be. e.g, in the switch. We had a roof leak a few years ago that got moisture into the back of a light switch. The LED bulbs in that room went bonkers too.

 

[fossyant]

Agree with the suggestion that leakage could be the cause. LED bulbs have a little power supply circuit inside. A tiny amount of leakage current can cause this to charge gradually up to the point that the bulb is able to light. When the bulb lights there’s not enough current to sustain it, so it goes out again. This repeats causing the flashing.

Particularly since it’s in a bathroom, check for any moisture where it shouldn’t be. e.g, in the switch. We had a roof leak a few years ago that got moisture into the back of a light switch. The LED bulbs in that room went bonkers too.

I'll be checking !

 

[neilrichardson55]

Agree the lights switch and connections need to be check, it sounds like you could have some power feeding back. bad connection switch or a short somewhere, an led cant switch on its own.

 

[T4tomo]

an led cant switch on its own.

Oooh ....apparently they can, its a real thing and some brands are more prone to it that others see @PapaZita post above or google it

 

[classic33]

The bulb is possessed, burn it at the stake.

 

[neilrichardson55]

Oooh ....apparently they can, its a real thing and some brands are more prone to it that others see @PapaZita post above or google it

really.... see its a school day, there must be something in the starter that holds power or static. i know when stormy, tubes used to glow
oh it was stray energy from the neutral makes more sence now

 

[Tail End Charlie]

Isn't there something about a switched positive besides a positive can induce enough current to dimly light the LED, or something like that? I only know my outside LED floodlight always glows and someone once said this was the reason.

 

[sevenfourate]

I heard the random flashing isn’t an indication of a dodgy bulb. But the go-ahead from above to get that new bike…….

 

[johnnyb47]

Carol Ann, Can you hear me 👻

 

[Bazzer]

+1 for the earlier suggestions of checking circuits.
On our landing we have some of the early GU10 LEDs. - Which didn't have a bypass capacitor fitted. So even with the switch off, they glow at night from the quiescent current.
Remarkably handy for nighttime bathroom visits, but could be spooky for anyone not used to them.