Using Dimmer Switches with LED Lights

By Todd Fratzel on Electrical

Not All Dimmers Work with Dimmable LED Lights

We recently wrote several articles about How To Install LED Lights in recessed light fixtures. The LED’s that we installed are a dimmable LED fixture which was a huge selling point for me as we use several dimmers in our home. Unfortunately I didn’t realize that just because an LED says it’s dimmable it doesn’t mean all dimmers will work.

Select Compatible LED Rated Dimmers

Before purchasing LED lights for your home it’s important to do some research. If you currently have dimmer switches on the circuits that you plan to install LED lights then take an inventory of the dimmer make and models. You’ll need that information to cross check the compatibility between the LED and the dimmer.

After installing the CREE EcoSmart LED’s in our home we started noticing some slight “blinking” and “dimming” of the LED’s at certain times. For example, when we would turn off another dimmer in an adjacent room the other room would slightly dim for a second or two. We also have a very slight flicker when the microwave is in use. Both of these issues occur on two different Lutron dimmer switch models.

Dimmer Issues with LED Lights

To better understand what was going on I spoke with Ken Byrd, Applications Engineering at CREE and asked him to explain the issues we were experiencing. Ken did a wonderful job explaining some of the more complicated engineering behind both the LED’s and the dimmers that make their marriage difficult.

Ken quickly pointed out that their website lists recommended dimmers that have been tested with their LED’s. In hind site I should have researched the dimmers a bit first but what’s done is done! Our home uses two Lutron dimmers, the Lutron RadioRA system and a pretty standard Lutron Toggle Dimmer. Unfortunately neither of these dimmers has been added to the recommended list of dimmers and is most likely responsible for the small issues we’re experiencing.

The issue is fairly technical but boils down to dimmers that were designed and manufactured to deal with higher electrical loads (600 watt dimmers versus a dimmer that might only see 60 watts!). The electronics that allow those dimmers to work are not designed to work with the lighter loads and voltages.

In addition to the problems that we are experiencing conventional dimmer switches may also cause the following problems with LED’s.

  • The LED lights may not work at all.
  • When dimmed it’s possible that there is early “drop out” where the light just turns off when even slightly dimmed.
  • Significant “noise” may be picked up in the dimmer and transmitted as flickering and uneven light.
  • Lights may just shut off at random times.

Dimmer Solutions for LED Lights

For now we plan on “living” with the slight inconvenience. Replacing our RadioRA dimmers would be quite costly and not something we’re willing to invest in right now. However, if you plan on buying LED lights then I recommend you do some research. Most dimmer manufacturers are now designing and offering LED rated dimmers.

For example, Lutron is now offering a family of C·L dimmers for dimmable CFL and LED bulbs. These dimmers are specifically designed to deal with the lower voltage lighting solutions while maintaining the functions of a versatile dimmer switch.

If you plan on installing LED lights in your home on dimmer switches then plan ahead. Do your research and find out which dimmers work well with the LED fixtures you want to install. This will save you money and aggravation after investing in LED lights.

About the author

Todd Fratzel

I'm full time builder for a large construction company in New Hampshire. I run their design-build division that specializes in custom homes, commercial design-build projects and sub-divisions. I'm also a licensed civil and structural engineer with extensive experience in civil and structural design and home construction. My hope is that I can share my experience in the home construction, home improvement and home renovation profession with other builders and home owners. I'm also the Editor-in-Chief and Founder of Tool Box Buzz. Please feel free to contact me if you have any questions, suggestions or you'd like to inquire about advertising on this site.

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14 Comments

  1. Tony C says:

    I have tried the Lutron LED dimmers and they flicker more than a standard dimmer does. EcoSmart lamps.

    • Todd says:

      Did you choose a LED Dimmer that was on the websites approved list? I’m told from the engineers of several different brands that you need to select a dimmer that has been tested and approved for the light fixture.

      • Anthony says:

        Same thing for me. The LED dimmers on my eco’Smart’ LED lights flicker like crazy. A standard dimmer works much better but also flicker when dimmed to certain levels. To me these lights suck and I’m going to return them for normal lights that don’t flicker.

        • Todd says:

          There are dimmers out there rated for these lights. For me, the flickering isn’t all that bad….the light quality and energy savings is far better.

  2. James says:

    I have also purchased the ecosmart dimmable lights with the “approved” LED Lutron dimmers…I have flickering at the higher light settings which their adjustable dial does not remedy. I dont know what to do about this as I cannot live with severe light flickering. Especially now that I have already removed the hangers for the standard bulbs from my canisters. Do you think it might have to do with the fact that I have six lights on each dimmer? I don’t understand why it happens more as the light gets brighter. I would have expected the opposite.

    • Todd says:

      Mine happens mostly at low light settings. Mine also only happens to the “other” circuits when I use a circuit. For example, the kitchen lights that are on a Lutron dimmer flicker slightly when I turn off the mudroom lights that are also on a Lutron dimmer. Again mine is worse when one is set low on the dimmer. I’m told part of the problem can be a polarity thing so you might check to see if the polarity is the same on both switches.

  3. Luke says:

    Most LED will flicker unless they have been tested appropriatly by both dimmer and lamp manufacturer. Lutron makes an LED/CFL dimmer and publishes a list of compatibile lamps.

    The driver inside is usually the culprit.

    http://wwww.t8LED.org has a few interesting linears for sale.

  4. Kevin H says:

    It’s looks like it’s been a while since this article was written. Have you found any LED dimmable bulbs that work well with your RadioRA dimmers?

    • Todd says:

      I have not. Seems like the solution may end up being the new line of dimmers. If I do find some I’ll be sure to post them here.

  5. Rod says:

    Expected to see manufacturers and models of dimmers listed in the article. Not real helpful

    • Todd says:

      Rod – The article was written 2 years ago….the industry was in complete chaos trying to find and match dimmers with the lights. The purpose of the article was to “warn” / “inform” readers that there are/were serious issues with dimmers and LED’s. Sorry you didn’t find what you wanted here.

  6. William Reid says:

    I have just come from my daughters home after installing LED lights in her kitchen. She had the touch style dimmers and they do not work at all.Had to install the old slide style type. One with an on/off switch and one without, the one without works a lot better, as when you switch off the dimmer with the switch, it wont turn on until you are about half way up the slide, and even then then the ammount of dimmed light is negligible.Probable because the lamps wont strike until a certain voltage is applied.

  7. Karl Gross says:

    I’ve been experiencing this issue of dimmer incompatibility even with a supposedly LED dimmer switch I purchased a Wal-Mart (made by GE, I think). I cant figure out why, but sometimes the bulbs light normally, but then suddenly cut to a dim glow – sometimes after a few minutes, sometimes after an hour – even when the switch is at full setting. Other times only one of the two bulbs in the fixture even comes on. Maybe the switch is defective, maybe it’s incompatible. It’s a shame, really, because it was the only push on and rotary I’ve seen that advertised LED compatibility. The Lutron and others all seem to be the standard switch with the small slider or the rotate on. It was also half the price of the others. Funny part is, I think the LED bulbs I’m using are dimmable LEDs made by GE, also purchased at Wal-Mart.

  8. winston says:

    I have a chandelier with 15 ecosmart 25w replacement candelabra base lamps and a Lutron C-L dimmer that allegedly works with dimmable LEDs/CHLs etc. It worked fine for a while now the lights remain on dim and won’t adjust. I replaced the dimmer switch with new of the same model, but the lights still remain dim (no change). Any ideas??

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