I have a knob dimmer that says on the metal plate "For permanently installed incandescent fixtures only" on it. I would like to replace that with a rocker style dimmer that accepts LEDs. The wording and the fact that the wires are inserted into the back just makes me want to confirm.

Edit: I opened the new one and it looks like my new switch has wires coming out of the back and you're supposed to attach a wire nut around the corresponding wire inside the box. Just gonna leave this up to be absolutely sure I can replace it at this point


  • 3
    the wording just means "don't use it on florescent lights" and also, for idiot-proofing, "don't dim an outlet", since it can have something plugged in that shouldn't be dimmed. – dandavis Oct 15 '18 at 17:49
  • Can you post photos of the inside of the box? – ThreePhaseEel Oct 15 '18 at 23:08
  • imgur.com/a/jmPAMNp ignore the exposed black, it's to another switch I was replacing, and yes power is off – bee Oct 16 '18 at 18:49

Many incandescent-only dimmers do not require a neutral wire. If that's the case then you will have hot, switched-hot and ground connected to the existing dimmer but not neutral. The new dimmer will likely require neutral. Neutral may be in the box in which case you have it easy. If not then it should be nearby and the challenge is to make sure that you have the correct neutral and bring it into the box, split it and pigtail to the neutral on the new dimmer. Code now requires neutral in all switch boxes but that has not always been the case.

The above is a general dimmer/smart switch/etc. issue.

Now for the specifics: Based on the UPC code of the package, this is a Lutron LECL-153PH-WH dimmer. I found the spec sheet for it and it explains the wiring. For a single switch (i.e., you have one dimmer switch controlling the lights and no secondary switch at the other side of the room):

  • Hot (typically black) to black wire of dimmer.
  • Red of dimmer to switched-hot (typically black or Harper's preference red)
  • Green to ground (green, bare or screwed to grounded metal box)
  • Red/white of dimmer capped - i.e., put a wire nut on it so that it isn't connected to anything.

The Red/white and Red are used together as travelers for a 3-way switch (2 switches controlling the same light).

  • IIRC our Lutron dimmer for LEDs does not require connection to a neutral. I think it is only "smart switches" that require a neutral connection. – Jim Stewart Oct 16 '18 at 14:06
  • imgur.com/a/jmPAMNp here is a picture of the new switch and the old in the box. I'm assuming red and red, black and black, then a red to the red and white? But how to tell which red? – bee Oct 16 '18 at 18:51
  • Assumptions bad. Reading instructions and markings good. There is no way the dimmer does not have instructions or markings. – longneck Oct 16 '18 at 20:17
  • Thanks but I assume before I actually do anything, and seek help or guidance, hence my question marks. The instructions show 2 black wires and the red and white goes to one of the black. Since I have two reds, this is useless. But from the internet I know hot can be red or black so I was intending on, if no one answered, doing more research. But fortunately another user has actually tried to help without condescension! – bee Oct 16 '18 at 21:05

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