Wiring for 3 gang box with GE smart fan/light switches and separate ceiling lights

I have a 3 gang box with 3 switches. One for the can ceiling lights, one for the ceiling fan lights, and one for the ceiling fan itself. This is my attempt at the original diagram:

It looks like there are two hot lines coming in. One (black) is daisy chained across all three switches to provide power. The second hot line (black) was connected to the fan’s light switch to the line insert on the back of the switch.

I connected a GE Smart Dimmer to the can lights successfully, and the old switches for the fan still worked. The neutral for the dimmer came from the neutral bundle, ground was connected, the line(hot) came from the daisy chain, and load(lights) to load on the smart switch.

I bought another GE smart dimmer and GE smart fan control to add to that box to control the ceiling fan. I checked the wires and figured out that the red coming from the fan controlled the lights, the black going to the other switch controlled the fan, so wiring up the two new switches seemed simple enough. I daisy chained the neutrals between all switches to save some space but bundled the first hot under a wire nut so I could go out to each LINE on the switches separately. For the second hot wire, I connected it to the LINE on the new GE dimmer, seemingly the same as the old switch was.

The dimmer for the can ceiling lights works great - still dims the lights and switches them on/off. The fan control works and controls the speed of the fan. The light switch for the fan, however, does not dim. It does switch the light on/off, but won’t dim. Also, when I turn off the ceiling lights, the fan light flickers a couple times as the ceiling lights dim off.

My initial thoughts is that it has to do with how the hot was daisy chained across all three switches. Could I separate everything to get the ceiling lights on its own circuit and the fan on its own circuit? If so, how?

I am confused a bit so let me see if I can clarify the initial wiring…

The wires called “Line” should be one coming in and one going out, not two incoming power lines. If you disconnect those wires, you should only have power on one of the blacks and that would be the line power from the breaker. If BOTH have power then there is a wiring mistake (disclaimer: I am not a licensed electrician). Assuming there is no wiring mistake, the fact that all the neutrals are tied together should mean they are all from the same breaker (or should be according to latest rules).

It appears that the two blacks from the “line” cables are connected one on a screw and the other on the insert port of that same switch. I really dislike this method as “insert ports” are the worst “lazy electrician” invention IMO. These connections are less reliable and are often to blame for weird light flickering issues (sometimes indication of a bad connection). A better way is to use a nut to bundle the wires you need together, with one wire going to each switch. This, at times, is hard due to lack of space.

I am not sure I follow how you wired stuff so let me tell you what I would do:

  1. Assumption: one “line” is from your breaker, the other “line” is something downstream powered by the same breaker (circuit).
  2. Cut 3 black wires of the same gauge long enough to work with and twist them to the two black wires from what you marked as “line”. Connect each one of these black wires to “Line” on your dimmers and fan controller.
  3. Do the same with the white wires. Essentially all dimmers/switches (assuming they are all operated by the same breaker - see #1) should be powered in parallel.
  4. Repeat #2/#3 for ground.
  5. Connect each load accordingly.

If this is what you did then the flickering might be due to some interference / incompatibility between dimmers / LED lights. I recently experienced a weird issue where a GE Motion Dimmer turning on LED lights in a bathroom was making LED bulbs on another dimmer flicker. Replacing the bulbs that were flickering fixed the issue.

What you’re describing makes sense now. I should have tested both black wires separately to determine which was hot. One thing I tried was connecting the black from the 2-wire (right one, that was in the insert of the fan’s light switch) to the LINE on the fan’s light switch and the other black (left) to the LINE on the ceiling lights. When I did that, there was no power going to the fan, but the ceiling lights work. Now I’m wondering what the other 2 wire is powering since there’s 3 wire romex going to the fan and 3 wire going to the ceiling lights. Regardless, I’ll try what you suggested tonight and report back. I’ll also try to remember to take pictures. Thanks!

Edit: I’m shuddering at the thought of stuffing all those wires back in there once I separate it out like you described. It was a pain as-is!

If one of the blacks labeled as line in your drawing powered a load and the other did not, then it matches my thought that one is from your breaker and the other is just some downstream part of the circuit.

Wires going to ceiling lights that are pre-wired for fans typically have a red/black/white/ground conductor. I believe red is typically used for the light part of a ceiling fan and black for the fan but I would not be surprised if this were not always the case.

Is it possible that the other ceiling light(s) are pre-wired for a ceiling fan? Red is also used as the traveler wire in a 3 way switch circuit. Could it be that the house once had a 3 way that was disabled? Is there a switch in that general area that does nothing or disables the light (meaning if turned off then you can no longer turn on the light from this other switch you are working on)?

In the event of a 3 way, this thread might help:

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My original diagram for the ceiling lights was a little off. I forgot that it is on a 3-way, so the red for the ceiling lights was connected as a traveler to the switch. I got that wired up successfully with the add-on switch on the slave on the other side of the room, and it works fine. Currently all three switches are powered. The ceiling lights dim and turn on/off. The fan light turns on/off. The fan turns on/off and can be speed controlled. The only thing not working is the dimming of the fan lights. If the switch has power, is grounded, and can turn on/off then shouldn’t it be able to dim?

I double checked the bulbs to make sure they were dimmable. Besides testing the wiring issues you suggested, I guess I need to try different bulbs or another dimmer switch as well.

Did the ceiling fan come with a remote? If so, I wonder whether there is a controller module in the canopy or baked into the fan itself to control fan speed and light dimming. If this were the case I would expect you would have issues with the fan control as well but I figured it would be good to ask anyway. I have 4 regular fans without any light or fan control other than the speed switch, and 3 large fans that came with such a module. For these 3 fans I removed the canopy module and wired them directly to wall dimmers and fans controllers.

Note: What I wrote in previous posts was based on not knowing it was a 3 way switch circuit. Please review the thread I linked to for 3 way switch wiring if you want to verify what you did… but it sounds like you already have it working. Mentioned it to avoid being blamed for bad advice :slight_smile:

Update: I changed out the Hyperikon E12 LED dimmables with some el cheapo incandescents, and they dim! It seems like everything is wired appropriately. The switch just didn’t play well with these bulbs. Thanks for the advice, arufell.

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Glad I could help! I have had that same issue with a HomeSeer WD200 dimmer and 9 filament LED bulbs recently. Swappinh bulbs out fixed the dimming but I am still not out of the woods…