I've got a Lutron "Plug-in lamp dimmer", Model PD-3PCL-WH, and tried several LED bulbs with it. They all said "fully dimmable" on the packaging.

It works, however seems like at most it dims to about 30-40% on lowest setting. A floor lamp in another room with regular incandescent bulbs and in-built dimmer goes down to "barely on" dimness.

Are all LED bulbs bad at dimming? Would other types of bulbs be better? Halogen? CFL? Good'ol incandescent?

  • Some LEDs dim more than other before shutting off. This value is sometimes available, but not always. Unfortunately our eyes are very bad at judging relative brightness, so when you say your LEDs dim to 30% of their brightness you are probably way off.
    – Hank
    Nov 26, 2014 at 3:02
  • (Most of our senses are roughly exponential, which contributes to the error in judging relative brightness.)
    – keshlam
    Nov 26, 2014 at 3:48
  • 2
    I am sure that my subjective % is off from a true value, but comparing it to incandescent bulb, subjectively, that's what it feels like. In either case, regular bulb can be barely on, while the LEDs are off... and then turn on bright enough to light the room... and wife is complaining that it's too bright...
    – Slav
    Nov 26, 2014 at 4:20

2 Answers 2


Generally speaking you need a dimmer designed for led or cfl bulbs. These will allow you to adjust the upper and lower ranges in order to dim the bulb correctly.

Ultimately incandescent bulbs are the best to dim since the light output is directly proportional to the voltage.

  • So the one I got says Works with dimmable LEDs and CFLs, as well as incandescent and halogen light bulbs, it's too universal? I need one just for LED?
    – Slav
    Nov 26, 2014 at 1:26
  • Most of them are pretty universal. Check the manual to see if you can adjust the upper and lower limits. I've had good experiences with Lutron Maestro dimmers.
    – Steven
    Nov 26, 2014 at 1:27
  • Incandescent get too hot too quick, what's the "second best" then? Thank you.
    – Slav
    Nov 26, 2014 at 1:46
  • 1
    Halogen, but they get even hotter. I'd say followed by LED, then CFL, then floro tubes.
    – Steven
    Nov 26, 2014 at 3:34

Have you adjusted the low-end trim? There is a PDF which they class as "advanced" instructions that describes the procedure on Page 25.

  1. Hold On button for 6 seconds, until LED (on dimmer) starts to flash.
  2. Hold Down button until lamp turns off or starts to flash.
  3. Tap Up button until lamp is not flashing and is stable (or is as bright as you want the lowest dim to be.)
  4. Hold Off button until the LED (on dimmer) stops flashing.
  • 1
    Ahh! This is just what I needed, didn't know about this. I wish I could award you more points than an upvote, but I worded my question in such a way that Steven's answer actually answers it (and I already accepted that). Also unfortunately, it didn't work for me: the small LED didn't blink, and the rest of instructions didn't work. I've double checked the model number, and it's same as on the document you linked. I will try calling their support.
    – Slav
    Nov 26, 2014 at 4:23
  • 1
    Hmm. Well, I'm sorry it's not working as described. No worries about the points, not a major fixation of mine. Let us know what you find out from support.
    – Ecnerwal
    Nov 26, 2014 at 5:05
  • +1 Always see that dropoff on the lower range with LEDs, normally fix it in the program with a full Lutron system. Didn't know you could do that with a standalone Lutron Product.
    – Brian Duke
    Nov 29, 2014 at 0:43

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