I have a two bulb set up with a dimmer switch. Both of these were non led bulbs. So i went on and replaced the bulbs with led. Now when i turn the switch off, one of the bulbs stays on with the dimmest light.

Are special light bulbs required for this setup. Is anyone familiar with this kind of setup? Btw the bulbs will work fine if i replace just one of them with led and the other one remains as is (non-led).


The issue is more than likely the dimmer switch itself. If you've changed from incandescent bulbs to LED bulbs then I'm 100% sure the dimmer is the issue. You'll need a dimmer that's LED compatible. Most LED compatible dimmers are also sufficient for use with CFL bulbs.

Note: Ensure your LED bulbs are dimmable as well.

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    Agree most older dimmers will have this problem with LED's and not all LED's are dimmable + – Ed Beal Jan 5 '19 at 1:03

Yes, that's how older dimmers, lighted switches, motion sensors and smart switches work. They need power to run themselves. But rather than supply hot and neutral to properly power the switch, they just hook themselves up in series with the incandescent bulb. This takes advantage of a fun fact about incandescents: when they are off, they are essentially a dead short.

But this fun fact is not true for LEDs, which have complex electronic power supplies to convert from the 120 volts AC to the 3 volts DC that LEDs actually run on. These power supplies respond unpredictably to this particular kind of power leakage. Quite often, the LED lights up a little bit, just like this. Now, you can see the power that the dimmer has been wasting all along.

It helps to buy LEDs rated for dimming, which have more complex power supplies designed to cope with this situation.

You can also get a dimmer that has a hard "off" position. They have a smooth dimming range from "low" to "high", but if you push past the "low" position, you go "over a bump" (stiff resistance) into a hard off position. Who knows? You might already have that, for most people it never occurs to them to try pushing past the bump.

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