I have 9 canister lights in my kitchen that I've replaced with "replacement LEDs." The lights are on a 2-way switch, one of which is a dimmer. Things were good for about 2 years, but now all 9 LEDs (well, 8 out of 9) are fairly dim -- still usable, but very different light output than when they were new. Perhaps 50% light output.

I'm wondering if this is a result of the dimmer switch. The dimmer is about 12 years old, so was constructed in the pre-LED era. I find it more likely that I have trouble with a single component (the dimmer) than that most of the canisters are failing.

Do I need a special dimmer to switch LED lights?

3 Answers 3


Do LED’s require special dimmers, It depends, with 9 lights there is probably enough of a load to operate properly (especially if they have worked fine for 2 years). If there was no glowing when turned off and flicker when new the lights are probably failing.

All the lights are in parallel so if they are all of a sudden operating at different light levels they may have been cheaply made and the drivers are failing.

It is possible your dimmer is not operating properly but with different light levels at the lights this points to driver failures

If you bypass the switch (power off) wire nut line to load and power on if the fixtures are dim that proves they are failing.

I suggest only purchasing DLC certified lamps and fixtures. DLC stands for Design Light Consortium, DLC required a 5 year warranty so they might be slightly more expensive but that is better than them failing not long after warranty. Also get your lights and fixtures from reputable dealers like 1000 bulbs. Com or LEDMYPlace.com (I get most of my lights and fixtures for work and home here , no affiliation other than a satisfied customer and the very few failures I have had they promptly replaced.


You need to have both dimmable LED bulbs/fixtures (some fixtures have built in LEDs that are not replaceable), and a dimmer designed to work with LEDs.

Most dimmers sold today will be marked as being compatible with LED, CFL and incandescent bulbs, but it's worth taking a look at the packaging, just to be sure.

Many LEDs sold today are dimmable, but not all of them are. It is very important to ensure that your bulbs are dimmable or you may be shortening their lifespan by running them at lower power.

I will note that a standard "old school" incandescent-only dimmer can dim dimmable LEDs. I installed a replacement ceiling fan that came with dimmable LEDs. However, I failed to remember to pick up a new dimmer for it. I wired it up to the old switch, and we dimmed it a couple of times, simply out of habit. The lights did dim, quite nicely in fact. However, I did pick up a proper dimmer & replaced the wall switch within a couple of days to ensure I wasn't destroying the bulbs any sooner than necessary.


Yes, LED lights require a special dimmer.

An old fashioned incandescent dimmer switch will not work properly with LED bulbs. You cannot just simply lower the voltage to the LED driver.

They make special dimmer switches for LED lights. You also need dimmable LED bulbs to work with the LED dimmer. Using non dimmable led bulbs can burn the bulbs out (shorten their life)

  • "You cannot just simply lower the voltage to the LED driver." - fyi that's not how nor why old dimmers don't work Apr 5, 2021 at 6:36
  • Actually (see my answer), you can simply lower the voltage to dim a LED. It's not good for it, but it does work.
    – FreeMan
    Apr 5, 2021 at 13:04
  • When I was a kid, I thought a dimmer switch was just a variable resistor. It was many years later that I learned that a "standard" incandescent dimmer is actually an SCR dimmer - far more complex. Apr 5, 2021 at 14:33
  • Accidentally downvoted :( Apr 6, 2021 at 17:04

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