I have a strange setup in one room of a house I bought. I'm not there at the moment so I can't provide photos so I will describe as well as I can.

On one side of the room there are two switches, one that turns the room light on and off, the other turns an outside light on and off. On the other side of the room there is a dimmer switch that can also turn the room light off. I never use this dimmer switch and would like to disable it. When I use the light switch, the lights flicker a couple of times and then slowly come up to 100% brightness.

This flickering, I believe, is causing issues with Smart lights as they keep resetting.

To be clear, I can turn off the lights from both switches, but the dimmer switch will override the main light switch if it is turned off. If the main switch is off the dimmer switch will not turn the lights on. If the main switch is on, the dimmer switch can turn the lights off.

How would I disable the dimmer switch to give full control of the lights over to the single on off switch on the other side of the room?

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  • Can you post photos of the insides of the junction boxes involved please? Feb 5, 2021 at 12:46
  • The simple answer is to remove the two hot wires (usually black) connected to the dimmer, wire-nut them together, then put a blank cover over the junction box. HOWEVER we really need a good, clear, focused picture of the wiring in both boxes (do not disconnect anything, just turn off the breaker first) to be 100% sure, especially since you're talking about "smart" devices.
    – FreeMan
    Feb 5, 2021 at 12:56
  • We'll wait for pictures, but it sounds like he doesn't have true 3-way switches. From his last paragraph, both switches need to be on for the lights to be on, but if either is off, the other can't turn them on. If this is correct, it would seem somebody wired a couple of single way switches in series. Feb 5, 2021 at 14:57
  • It sounds like your switch is wired wrong. A traveler and the common are mixed up but it could be the dimmer. I would replace the dimmer with a standard 3 way switch and verify that the 3 way switches are operating properly if one controls the other a traveler and common are usually swapped.
    – Ed Beal
    Feb 5, 2021 at 15:26
  • What's your reasoning for using a smart bulb here instead of smart switches? Feb 28, 2021 at 19:57

1 Answer 1


A key question, as noted in the comments, is whether this is a real 3-way setup, where either switch can be used at any time to turn the light on or off, or some sort of "crazy thing" (like in the dining room I grew up with - timer replaced one 3-way switch and we had to always remember to leave the other switch "on").

Assuming this is a proper 3-way switch, with one of the switches being the dimmer:

  1. Turn off power at the breaker
  2. Open up the dimmer switch. You should find 3 wires (plus possibly a green or bare ground wire).
  3. Determine which wire is common (which may be hot or switched hot, but doesn't actually matter much) and which two wires are travellers. How you do that will vary depending on the setup. If the wires attach to screws on the dimmer then usually two screws will be one color and the 3rd screw will be a different color. The screws with the same color should be the travellers. Or the wires may actually be labelled on the dimmer. But color (except green for ground) is no guarantee of anything (unless wires are part of the dimmer and labelled on the dimmer). If it isn't 100% clear, upload pictures before disconnecting any wires.
  4. Remove the dimmer and install a simple 3-way switch (you can get regular or Decora, plus get a face plate to match). The new switch will come with instructions that should make it very clear which wires or screws are for the travellers.
  5. Put everything back together and turn on the power.
  • Can I just tie off wires without adding the 3-way switch?
    – Michael
    Feb 28, 2021 at 19:01
  • Yes, but why? 3-way switches are very useful in large rooms (and in stairways and other places too). Plus, if you do that then you have to put a blank plate on in place of the dimmer (to avoid people trying to use the dimmer as a switch, unsuccessfully). A proper 3-way switch will cost you less than $4 at Home Depot Feb 28, 2021 at 19:19
  • Mainly because I just want to control the lights using a smart app. Can you tell by the photos which wires can be disabled? When I took out the wires the Red/Black wire combo came apart and that disables the lights completely regardless of the switch.
    – Michael
    Feb 28, 2021 at 19:22
  • How are you connecting to the smart app? Smart bulbs? What about if you go into the room in the middle of the night and left your phone in the bedroom? Feb 28, 2021 at 19:23
  • 1
    Far better would be a smart switch controlling ordinary bulbs. That allows for regular switch operation as well (in case any component of Alexa is not working). Plus (depending on the type of room and code requirements) there may be an issue of a requirement for normal switch operations (e.g., so if paramedics come in an emergency and the room is dark they can turn on the lights easily. Feb 28, 2021 at 19:31

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