GE CYNC Smart Dimmer Light Switch, Neutral Wire Required, Bluetooth and 2.4 GHz WiFi 4-Wire Switch, Works with Amazon Alexa and Google Home, White (1 Pack)

Tried nearly all of them, ended up with 4-wire design
I originally had a 3-wire switch that seemed to work just fine, except in my application. Let me explain. I replaced my ceiling fan which is deemed to be “smart”. Nowadays that means some form of app control, but really only mean there is no wall switch and only a remote. It does have an LED light kit and that’s where the 3-wire Cync switch ran into problems. Namely, it seems to condition the power on the load wire in a way that disabled (permanently off) the light kit. And you have to use it in line with the load wire in order to power the unit, which it draws from the difference created by the load. Bypassing the switch solved that problem, but not my needs of using the wall switch position for a switch to turn the Cync light strips (indirect lighting) on/off.Sure a solution would have been to go with a wireless switch, just that this version doesn’t support Alexa and most importantly doesn’t feature the glow ring which I quickly grew attached to. In my situation, the wall switch previously powered outlets until I repurposed it to power my old fan. Hence, I had a neutral wire to work with and that enables the use of the 4-wire version. My inquiries about that application returned generally that the load wire still is needed and therefore it’s unlikely that the 4-wire version is the solution.However, when reviewing the specs it turns out that the neutral wire (in addition to the line) provides a closed circuit and it’s a bit unclear what the load wire does (other than providing to a light fixture albeit not controlling it). For my needs, I tried to simply connect the wires to the available line and neutral, but not use the load wire as that was already bypassed (to mentioned fan). According to Cync, the Load wire is mandatory, even in the 4-wire design. Then again, unlike the 3-wire version, there is no minimum load requirement, which technically means it could be 0W or even open.It sure confirmed to be true and once I wired neutral and line to the switch, it booted up even with the load wire (red) disconnected. Problem solved! The switch is recognized by the app, and controls my CYNC full color light strips as intended. The brightness control works well, too. And of course the soft glow ring around the switch is there, too.A positive side effect is that apparently the 4-wire dimmer switch is currently on sale for $29 whereas the 3-wire version costs more. The latter is theoretically more versatile, but may affect devices on the load wire more than desired. Hence, if there is a white (neutral) wire, the 4-wire switch works better for me.

You may have to fight with the app in the beginning
There’s another review that pretty much covers my experience… except that I ultimately got mine working and now I love it!It’s been less than a week, so I will update the review if things go south.The install instructions are pretty thorough, though you will need to be able to identify the lead/load/ground/neutral wires on your old switch with your own smarts or guidance from elsewhere. The physical install itself was smooth, the app appeared to connect, but I could not get the dimmer to work, and the app would not let me change my bulb type. It eventually became apparent that the app was not connecting with the dimmer, and had only briefly connected to it.I cut the power to the switch, then did a factory reset on the dimmer, and after a lot of effort and frustration, got the app connected to the dimmer (for real this time.) Tip: if you can’t change the bulb-type setting, see if you can change any other settings. If you cannot alter any settings, you should consider disconnecting and reconnecting the app.When I finally got the app connected and changed the setting to register that I had dimmable LED bulbs, the dimmer switch flashed red. There was no reason for this, as the load was not excessive from the LEDs, but since I had multiple bulbs in the fixture (chandelier with candelabra bulbs), I removed half of them and tried again. It worked, and I was able to add the bulbs back on. I did this one at a time, but I don’t know that such a prolonged effort was necessary. I suspect the initial brief red flash was a glitch. Everything has worked perfectly since then. All-in-all, the app hooked up better than several other smart devices I have used, but you have to be prepared to put the effort in it and face some frustration, so only four stars.