The reason for that is that you need a complete circuit for most of them so that the wifi works. No neutral, no power. Without the neutral you have the power line and the load line which isn’t a complete circuit until you turn the light on and the neutral is connected through the light.
Found this online:
Option 2 – Smart Switches That Don’t Require a Neutral Wire
There are dimmable smart switches on the market that can be installed without a neutral wire. The key is the dimming feature, which turns the flow of power between the light and the switch down to a slight trickle. The flow of power is not enough to activate the light bulb, but it provides enough power to keep the switch communicating with your smart hub.
However, it is very important that you confirm that your dimmable smart switch will work with the type of light bulbs you plan to use – many will only work with outdated incandescent bulbs.
Like many here, my 1953 house with the original wiring does not have a neutral or a ground. Every outlet and light switch has only 2 wires. I am not going thru the expense of rewiring the house and swapping out the breaker box. I have a Wyze HMS with cams and a thermostat but I had to install the GE Sync smart switches because they are the only ones on the market compatible with my wiring and ecosystem. Would be nice if Wyze had a no neutral switch solution.
Assuming it is battery operated and just charges while the light is on, I hope it’s designed to have an option to turn the light on for a minutes when the battery gets low, maybe during preferred hours (so it doesn’t do it in my bedroom while I’m sleeping). That would be awesome.
The ones I use now and others on the market are not battery operated. To keep power to the smart parts when the switch and fixture is off (since there is no neutral to route constant power for the smarts) the trick is to perfectly regulate the resistance to allow just enough power to flow thru for the smart bits without enough power to turn on the fixture.
Mine are standalone WiFi with no hub. One drawback of this design is their WiFi signal strength is very temperamental and they do go offline if too far from the WiFi and someone walks in front of them blocking the signal. Some on the market use a hub to overcome the weak WiFi issues.
If Wyze can overcome this, they will have a significant advantage. If they go the hub route, not so much as it will limit application to only those with a Sense Hub which is an added investment they do not offer for individual purchase.
That would be even better. I have not looked at a lot of options for non-neutral wiring switches. I am guessing though, that Wyze wouldn’t have it connect to the HMS Sense Hub anyway. If they had it connect to anything besides direct WiFi, it would probably be that new “Universal Chime” thing the VP of Product told us about.
He did say that it would serve lots of products. In that case, it would probably be available for individual purchase.
I have heard that a lot of the ones that stay on all the time aren’t compatible with LED bulbs though because any current at all decides if they’re on or not, so even keeping it low keeps them turned on, so you have to use incandescent lights with them instead of smart bulbs. That would be slightly disappointing. Hopefully Wyze has some kind of solution to that so we can use smart bulbs with them too.
Do the options you have experience with allow you to use smart LED bulbs with them?
Of course, all of this is just speculation for now until they give us more info officially. I am just happy there is something coming. Most of the options I looked at 2 years ago were really expensive or didn’t work very well.
Now if we can finally get something that will automate the lighting effectively in a large room.
I haven’t found anything yet that works well for automated lighting of a large room where people will sometimes be sitting down, etc. (motion sensors don’t cover the whole room and definitely can’t tell when someone is sitting down watching TV, Cameras COULD do this, but they aren’t enabled to be able to do this to decide when to shut off the lights). Some day I hope that gets resolved.
The switches I bought come with a bulb adapter if the LED bulb is incompatible. I have mine running direct LED bulbs without the adapter and haven’t had any issues yet. I haven’t tried the smart bulbs in them because that would be redundant and would force the smart bulb offline when the Smart switch is off. The switch is the smarts for the dumb bulb to allow the Alexa integration and scheduling and all.
The ones I got do not have the dimmer option although they are available. At nearly $40 each just for the basic WiFi ones, I wasn’t really liking the $70 one. I think they also have them with fan controllers, but my fans are direct power without a wall switch.
I think the other big advantage of using the bulb adapters is the smart switch stays powered even when the lightbulb dies or is removed. (I haven’t had to use one of these neutral-less systems yet, although I could use a C-wire-less thermostat.)
Oh, well, I know hardly anything about HVAC, I just followed the instructions…well, more accurately, I followed the instructions the second time after my first guess didn’t work I don’t know what’s normal or not.
I just use clear packing tape on the top of the switch, (I have the large rectangle ones). Otherwise someone might turn off the side flood light, that originally was not smart, and the switch is a normal rocker switch. If they try to turn the switch off it won’t budge.
Yes, I enjoyed reviewing the schematics. Up until Wyze came out with their long requested light switch, I was still using a bunch of X-10 devices (formerly BSR). I had alarm systems in a couple of friends/families houses. When they move out, I reclaimed the equipment. I also stocked up on a bunch of most everything as spares, because I felt X-10 was soon to disappear. I still have most of it stored in my seldom used electronic shop. Such is life.