# dimmers and non-dimmable bulbs **URL:** \ **Category:** Factual Questions\ **Created:** [July 16, 2014, 8:55pm UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300 "2014-07-16T20:55:51Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![arseNal](https://avatars.discourse-cdn.com/v4/letter/a/ecae2f/32.png) [@arseNal](https://boards.straightdope.com/u/arseNal)\ **Post date:** [July 16, 2014, 8:55pm UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/1 "2014-07-16T20:55:51Z")
If you have a dimmer switch but never actually use the dimming functionality (i.e., always leave it in the highest/brightest position), is it still dangerous to use a non-dimmable bulb with it? Also, is this a problem only with CFL bulbs, or any non-incandescent bulb? I’m vaguely aware that there are different kinds of dimmers that would affect the answer to this question, so if it helps, let’s assume that the dimmer switch is just a standard, big box store, relatively inexpensive one manufactured in say, the last 10 years. Similar to this: [http://www.lowes.com/pd\_438350-539-SCL-153PH-WH\_0\_\_?productId=4165017&Ntt=dimmer+switch&pl=1¤tURL=%3FNtt%3Ddimmer%2Bswitch&facetInfo=](http://www.lowes.com/pd_438350-539-SCL-153PH-WH_0__?productId=4165017&Ntt=dimmer+switch&pl=1¤tURL=%3FNtt%3Ddimmer%2Bswitch&facetInfo=) ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [July 16, 2014, 9:57pm UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/2 "2014-07-16T21:57:46Z")
LED’s are usually fine (and actually dimmable) with a dimmer switch. I don’t know about CFL’s, though. ---
**Author:** ![arseNal](https://avatars.discourse-cdn.com/v4/letter/a/ecae2f/32.png) [@arseNal](https://boards.straightdope.com/u/arseNal)\ **Post date:** [July 17, 2014, 11:19pm UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/3 "2014-07-17T23:19:38Z")
Actually, I notice that there are LED bulbs that are labelled dimmable, so that leads me to believe that if they’re not thusly labelled, then they aren’t supposed to be used with a dimmer. So there goes that, I guess. Also, I wanted to give this one bump. I need to improve my question-asking in GQ somehow. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [July 18, 2014, 12:26am UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/4 "2014-07-18T00:26:31Z")
I’m ready to be corrected, but I think the issue with non dimmable LED lights is that they will just cut off rather than smoothly dim. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 18, 2014, 1:14am UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/5 "2014-07-18T01:14:48Z")
> [@GaryM](#): > > I’m ready to be corrected, but I think the issue with non dimmable LED lights is that they will just cut off rather than smoothly dim. This is true, but they can also be destroyed by dimmers. They pull too much current at a low dim setting, and that burns out the LED power supply. ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [July 18, 2014, 1:40am UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/6 "2014-07-18T01:40:51Z")
I have several regular (not labelled as dimmable) G10 LED’s in my bathroom on a dimmer. They are about two years old 3 different brands and have all failed in the past couple months. That is probably longer than halogens would last but I expect LED’s to last at least twice that. I’m guessing its not good for them. ---
**Author:** ![Mdcastle](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mdcastle](https://boards.straightdope.com/u/Mdcastle)\ **Post date:** [July 18, 2014, 3:54am UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/7 "2014-07-18T03:54:45Z")
My WAG is that unless the dimmer is a type that cuts out the triac when fully on, it may still do something that the bulb doesn’t like. ---
**Author:** ![EdwinAmi](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@EdwinAmi](https://boards.straightdope.com/u/EdwinAmi)\ **Post date:** [July 18, 2014, 4:25am UTC](https://boards.straightdope.com/t/dimmers-and-non-dimmable-bulbs/693300/8 "2014-07-18T04:25:36Z")
dimmers mess with fluorescent lights messing with the dimmer too much on a fluorescent light of any kind can/probably will kill the life of the fluorescent light, I’ve experienced this first hand