Temporary set-up: 3-way, one box no neutral. Safe for now with 1 Smart Switch?

Hello - I’ve read a lot on this forum over the years to get help (thank you) but this is my first post. I have a new construction home where I am installing smart switches. I took more than 30 out of the old home and brought them with me, so I’m familiar with wiring and getting things to work.

One 3-way switch that controls patio LED lights (attached to fans, separate switch) does not have a neutral in the box. The other does. I plan on getting the electrician out to run a neutral to the box under warranty, but I do have things temporarily working.

I have a GE Smart Dimmer on one box (which I believe is the auxiliary based on the pictures), and the other (I believe is the master) I left alone with the original switch since there is no neutral. If the dumb switch is on, I can operate the smart switch normally. If the dumb switch is off, the smart switch has no power. This is ok with me as I plan on using a door sensor to operate the lights anyway.

I’m only allowed one pictures, so I showed the wiring for where I put the smart switch. Note the wire colors are screwy because we are dealing with fan and fan lights on separate switches, but on the same circuit. They used two reds in the one box, one being a traveler and one being what I believe is the fan load (I verified red wires for lights when hanging the fans). A white cord is also used as a traveler, separate from the neutrals in the one box.

Question is - is this setup safe? All of my knowledge and reading says ‘yes’ but was hoping someone with more experience can verify. I couldn’t find another post with someone with one smart switch and one regular operating together like this.

I thank you for all of the help over the years, especially the 3-way FAQ which I’ve poured over many times.


Get the Lutron Casetta switch and PICO for an awesome three way without neutral wire setup. I have two of them setup and they work flawlessly.

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If you have a white traveller between switches, you can just wire that to your neutral for your slave switch.

Do not use a smart switch with a regular 3 way switch. You will either damage the smart switch or just disable it entirely when the 3 way is off. While you can do the latter it’ll cause disruptions in your mesh. Smart switches are designed to be powered on all the time.

Hi, I want to update my 3 way switches to a TP Link 3 way smart switches but on one of the box there is no neutral. Seems like the TP link have 2 slots for the traveler wire, is it okay to only use 1 traveler wire and the other traveler wire I tap it into the neutral? Thanks!

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Hi Tran,
three way switches require the two traveler wires as connections between switches and cannot be changed to neutral and eliminate one traveler.

Buy the Caseta switches by Lutron. You can create a three way switch easily with or without neutral. I have one that sits at the top and bottom of my stairs and it works awesome. Never ever failed.