I have installed smart switches before, but I moved into a new apartment recently. I have never had a problem before. I removed my old light switch and installed a new smart wifi light switch, and I lost power to my entire room. (All wall outlets, switches, etc)

The light switch powered up, but did not turn on the light, nor allow me to use anything else in my room. I hooked the ground to ground, hot to black on the switch, load (red wire) to the red wire on the switch, and unbunded the white neutral wired in the back and hooked it to neutral.

I also noticed that fully disconnecting the smart switch and leaving all wires 'safely' exposed, my room did not have its' power restored. I did this to test and see if the switch was bad or my wiring was somehow wrong.

It wasn't until I hooked back up the old light switch and re-bundled the neutral wire that everything started working again.

What is going on here? Is it something to do with the neutral?

Also: I noticed that when the power was on, wires were exposed, but no power was going to the rest of the room, ground-load measured 120v. ground-hot measured 120v. Why was load measuring 120v?

Measuring load-ground when the original switch was working measured 0v with switch off.

enter image description here enter image description here

2 Answers 2


Because of what you did with the neutrals

You needed a neutral so you unbundled one from that bunch of "spare neutrals back there". That's what broke it. It is a common misconception.

All those neutrals already had a job to do. Since you have seen the results of disconnecting them, you know what that job is. I bet if you plug a 3-light tester into the downline sockets, you'd get only 1 yellow on the end.

Anyway, reconnect all those neutrals the way you found them. This should restore your plugs. I understand your smart switch needs a neutral, you need to add it to all those neutrals. If it binds 3 neutrals it will now bind 4.

Not all whites are neutral. All neutrals are white, but not the other way 'round. Wire color does not designate function, but is simply how cables are made.

Now there are two other potential problems.

  • That brand is not sold by any reputable shop. It is sold only on Amazon "Marketplace" and eBay (and Walmart which simply relabels Amazon listings). That almost certainly means the brand is a Chinese cheapie that is sold that way to evade product safety laws. It cannot be sold retail because is unable to qualify for a UL listing (or equivalent Nationally Recognized Testing Lab), becuase it is unsafe. You should never install products like this, and you will face severe civil liability if there's fire or injury as a result. The sick thing is, they're not even that much cheaper than listed product.
  • it sounds like you are renting. You must never do any electrical work without the permission of the landlord. Even with permission, electrical work in a rental unit must be done by a licensed electrician, though your local jurisdiction may allow self-changes of receptacles and light switches because they are pretty simple.
  • That was exactly it! I read and had always considered them spare neutrals for future installs. Stupid of me. Thank you Harper. Curiosity got the better of me and I just had to know why instead of eventually getting it to work. Permissions from landlord was granted and we are allowed to change light switches around me. I've had to deal with this after moving around so much in my city. All other switches I have are GE z-wave, this is my only wifi switch from Amazon. Wanted to test it. Thank you for the help and info!!
    – CREW
    Commented Feb 12, 2019 at 5:18
  • If you have a chance, could you elaborate a bit on the light tester and yellow end point you made earlier?
    – CREW
    Commented Feb 12, 2019 at 5:21
  • Those testers work like this @CREW Commented Feb 12, 2019 at 19:21

Since the switch powered up It is possible that the line side neutral or hot was not making a good connection to power the other devices. I would reinstall the switch since you work working with the neutral bundle I would focus on that as the highest probability.

  • Not a secure connection might explain the light not being powered up. But why would the rest of the room not be receiving power? (Breaker is not tripped), Is some wire on that switch being used to power the other outlets and switches in the room? Is this heard of?
    – CREW
    Commented Feb 12, 2019 at 0:29
  • The line side neutral is the return path, if this was only making a good contact with the switch and not the feed for the other devices they would all be dead. Very often a room lighting and outlets are fed from the same circuit.
    – Ed Beal
    Commented Feb 12, 2019 at 0:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.