Need help with 3-way switch wiring

Just bought some TP-Link HS210 3-way switches and can’t for the life of me understand why one box has a neutral wire and the other one doesn’t have any (that I can see). I’ve read the GE faq thing and legit couldn’t find a way to fix the problem I’m having. Though I figure pictures do help to understand what’s going on, on my end so I will do so!

Please any help would be appreciated!

With a 3-way switch, you won’t have a neutral in both boxes, just one.

From a limited view of your pictures, my first guess would be that you have power going to the box on the left. The light is in the middle and then you have the box on the right at the end of the leg. Like this:


For the box on the left, I’m guessing that you have a 2-wire Romex with the black going to the black screw on the switch and the white bundled in the box. Pull the black from the switch and test to see if it is constantly hot. Test against either the white bundle or the bare ground.

If I’m correct, then the other Romex in the left box is a 3-wire. The white is bundled with the other white and the black and red are connected to the two black screws on the switch.

Go so far? Your smart switch goes in the left box.

not sure if those pictures will help more. Though I’m not fully understanding how I’m suppose to get my neutral wire from the single box(left box). The TPlink 3way comes in pairs for both switches and both require a neutral. Also thanks for the patience!

That picture you just posted does make it appear things are not as I first thought. How many Romex are in the box on the left? I originally thought that it was two but now it looks to me as if it is one 4-wire. Is that correct?

I am not familiar with the tp-link switches so I won’t be able to help you there.

There are 4 on the left yes. 2 black, red, ground. I thought there would be black, red, white, and ground. So when I looked at this I was extremely confused on to how I should be doing this

When was your house built? Our current house was built in the mid 90s and most of the boxes had no neutral. The neutrals are probably tied together up at the light. I had electricians come in and add neutrals to many of the boxes in my house. Crawling around in the attic is not something I want to do anymore.

Another option is the Inovelli switches. They don’t require a neutral but you it works best with incandescent lights. You can use LEDS but you may have to add a load to it. I am using one in a single light and it works great. Supposedly they can be set up in 3 way switches configurations as well, but I haven’t dome that so I can’t say how well it works.

My house was built in late 2019. Which is odd because it shouldnt be this difficult

Ok, so that’s still a 3-wire on the left. How is the switch in the box on the right wired?

I started on that switch and it works perfectly fine but the other switch (left picture from earlier) I can’t get to work. Though I took a closer picture of the wiring of the right switch. That switch (right switch from earlier) shares the box with a fan switch. From that Romex (from what I can tell) has a red and two blacks. Though a red is coming from a different Romex to connect to the switch and I don’t know why.

hopefully another picture won’t hurt as well

Still tough, but here is what MIGHT be going on. One common way of wiring a 3-way circuit is to start with a constant hot in one box and send it to the other to switch where it is sent back switched over the travelers. It then goes back through the switch in the box where it started and then to the light.

In the box with the 2 switches, you’ll see several blacks bundled together. That is likely a constant hot, but you should test to confirm.

It looks like the constant hot is connected to the 3-wire (top left in the box) which may the 3-wire going to the other box. I’m guessing that the whites that are bundled are the neutrals, so if you go with a Zooz, GE or Inovelli, the smart switch will go in this box.

I’m also guessing that in the box with the two switches, the Romex coming in from the top has the red connector that is going to the light. Was that connected to the black terminal on the old dumb switch?

In the box with the single switch, you have to identify which conductor is constantly hot but disconnecting the blacks and testing with the other switch in both positions. If I’m correct, the constant hot is being sent to that single switch box via one black and coming back over the other black and red.

I notice one of the conductors in the two switch box is labeled. Is that your label or did the electrician do it? What does it say.

This is about as much as I can tell you without testing.

If you are uncertain, I recommend that you contact an electrician.

Tagging @ritchierich

There aren’t two blacks in that one switch. The white is painted black which some electricians will do or use electrical tape.

The box with two switches has line and load. Remember the key to 3 ways is to look at the common terminal on the dumb switches. The box with a single switch has the white painted wire on the black screw and if you follow it in the box with two switches you will see it going to the bundle of black wires, line from breaker.

Then the switch in the two gang box common screw is red which is load. That box also has neutral.

So just like I have mentioned in the 3way FAQ you need to move that black painted white wire from the black bundle to either the neutral bundle or the extra neutral terminal on the switch to send neutral to the other box. Then everything else should be straight forward.

Hope this helps!

I will definitely give that a go in the morning. Nothing else to do during quarantine! Thank you both for the info. This was all too big brain for me so I knew you guys would come in the clutch!

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Looks like a white wire tucked on the left side…Either way, you have plenty of wires to make it work. You only need one traveler in most cases. You can repurpose one of the blacks. Track it down and tape it with white electrical tape.

I think that’s a black that got hit with overspray. Why painters refuse to plug a box with a paper towel is beyond me!

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There has to be a junction box somewhere… There are 2 reds coming off the switch. This is Romex so where’s the 2 reds going and why doesn’t the other switch have 2 reds as well?..

My money is on that being a white wire painted black. That’s definitely a Romex wire in that box yet I see no white wire. The black is much darker than this one.

I have not messed with the switch today. Got caught up with other things but will give it a go soon. Thanks again all!

If you’re referring to the box with the two switches, the reds are from two different Romex. One of them is going to load.

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You have got to be right but that is bizarre. I have never seen anyone paint a conductor before. Black tape, yes.