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I am trying to replace 4 switches from old style to smart switches. I first tried to just hook up the wires like they were on the old switch (no light). I then undid the bundle of white wires (8 of them pulled one out and put it in the neutral wire place bundled the balance of the wires now the light just blinks.

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  • Old analog switches and new digital (smart) switches are wired differently as you found out. You need to precisely follow the instructions for the smart switches. If you still don't know what you're doing - stop! Make sure power is off and take some pictures of the inside of the boxes and edit them into your question. Pls provide make and model # for the new switches and someone will help you.
    – HoneyDo
    Commented Dec 18, 2021 at 21:43
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    Current flows in loops, everywhere hot goes to, neutral must come back from or you don't have a loop. So if you grab one neutral out of a bundle, that means one branch of the circuit is unable to complete its loop. So any such bundles need to be kept together and added to - never removed from. But 8 is too many to easily splice - something is odd about this box. Can you post photos? Commented Dec 18, 2021 at 21:59

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You can't just steal a random white wire from a bundle like that. They all need to stay connected for everything to work.

If you get "lucky" and pull the neutral that goes back to your electrical panel, the smart switch will have power, but none of your loads will have a complete circuit back to the panel. If you grab a load neutral wire, the switch won't function.

The correct approach is to use a "pigtail", a short piece of wire from the switch to the existing neutral bundle. Or if the switch has its own wires attached (and they're long enough) put that wire in the existing neutral bundle. Of course if you really had 8 white wires all wire-nutted together, you may end up with too many wires for one wire nut. They can be split into groups each small enough for one wire nut, joined by a pigtail.

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  • how do you add pictures to a question?
    – Pam Lee
    Commented Dec 18, 2021 at 22:12
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    Click the "edit" link under the question and use the icon that looks like a mountain (sixth from the left).
    – nobody
    Commented Dec 18, 2021 at 22:18
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Pictures would help. The following is based on a common (but not the only) way of doing things.

Not sure how/why you have 8 white wires. The typical setup would be:

  • One cable coming in (hot/neutral from panel)
  • One cable going out for each switch = 4 cables
  • One cable going on to the next location

That would be 6 black hot/switched hot and 6 white/neutral, as follows for "dumb" switches:

  • Incoming hot pigtailed to hot wires for all 4 switches and the outgoing hot. Alternatively could be daisy-chained between the switches.
  • All white neutrals together.
  • Each switch's second connection (switched hot) connected to a switched hot going to one load.

Smart switches (generally) need neutral and they generally care about hot vs. switched hot, where dumb switches don't care if you have hot on top and switched hot on bottom or vice versa (or left/right - screw configuration depends on the particular type of switch). Which means:

  • The hots and switched hots are connected the same as before. However, you need to make sure you know which wires are hot and which are switched hot. Simply connecting (assuming old and new have, for example, hot and switched hot on the same side of every switch) "old top of switch wire to new top of switch screw, old bottom of switch wire to new bottom of switch screw" may not be correct.
  • You need to add 4 additional pigtails (white wire) from the neutrals of the new switches to the combined existing (6 by my count, 8 in original post) white neutral wires.

You can't normally put 10 wires in one wire nut. You may be able to do some daisy-chaining, or you may just need to use 2 or 3 wire nuts instead of 1. For example, 10 neutrals connected together could be:

  • 3 existing wires in first wire nut + 2 new pigtails
  • 3 existing wires in second wire nut + 1 pigtail from first bunch
  • 4 new wires (the 4 smart switches) in third wire nut + 1 pigtail from first bunch

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