Electronic – LED lamps keep glowing when dimmer is turned off

dimmerled

For starters, I am not electrically capable, so bear with me. But, I did read similar questions that did not address, as far as I could tell, what I see happening (they may have, but I was too illiterate to understand).

I hired an electrician to replace an existing chandelier (19 years old, including dimmer switch is 19 years old). I bought 6 expensive ($10 each) Energetic LED soft white 3000K bulbs. These are marked 'Dimmable'. The chandelier is on a dimmer switch where off has meant off, in the past.

I installed 6 bulbs into the chandelier, turned them on bright. All is well. Turned them off, they remained 'on' (rather dim, but still not all that dim).

I also bought $9 bulbs (not dimmable) for another fixture.
I also have a lamp nearby with the old fashioned light bulb.
I unscrewed 1 of the 6 on the chandelier. It, of course, went out. The other 5 stayed lit. I then screwed in the old fashioned light bulb. All 5 LED lights went out!!! I turned on the light switch, and all 6 turned on. I turned it off and then unscrewed the old fashioned bulb – all 5 LED came back on!!!!
I then replaced it with a $9 LED bulb, non dimmable. $9 bulb did not light. But the 5 LEDs that were still glowing continued to glow.

So, I have a problem. I want the lights to go off when turned off.
Might the problem be the bulbs?
The wiring of the new chandelier?
The age/wiring of the dimmer switch?
Something else?

Hopefully, you can tell from the content of this, that I know very very little. If you start talking to me about MOSFET, capacitors, snubbers and the like, it will likely go over my head. I will ask my electrician to come back out, but thought I would see what enlightenment I could obtain here.

Best Answer

Buy a dimmer designed for LEDs. Your typical light dimmer puts out pulses of power; the brighter the setting the wider the pulses. This is OK for incandescent lamps as they draw lot of current and need a brief time to turn on and off.

LED lamps draw about 1/10th as much current and turn on and off in millionths of a second, so the same narrow pulses that make an incandescent light dim will make an LED light at least medium bright, maybe even flicker a bit.

You could "cheat" a bit by plugging in a incandescent bulb off in a corner to act as a minimum load which helps the LEDs behave better, but in the long run it is best to install the correct dimmer for the LEDs. Almost any hardware store should have them.