Blue 2-1 in 3-way setup with neutral and dumb switch

Hi there - trying to setup a new Blue 2-1 switch in a 3-way setup.
There is a neutral and have confirmed that it is the Line/Load in separate boxes via multimeter testing. I have editing the dimmer configuration to indicate that it’s a dimmer, in a 3-way setup with a dumb switch.

For usability reasons, I would like to install the Blue 2-1 dimmer not on the line side of the diagram, but instead on the load side. Is this possible or do I have to install it on the “line” side of the circuit?

I’ve tried installing on the load side and am seeing the following symptoms:

  • If dumb switch is on, dimmer switch works as expected ( can turn light on or off from dimmer)
  • if dumb switch is off, dimmer switch does not receive power (i.e., LED is not lit) and does not behave as expected (light is always off)

I can confirm that the red traveler wire coming into the dimmer (from the dumb switch) has 120V when the dumb switch is off. I can also confirm that the black “line” wire coming into the dimmer (from the dumb switch) has 120V when the dumb switch is off. The dimmer does not seem to receive power from the traveler, but only when the “Line” is hot.

Is there a way to configure the dimmer to be powered from the travel in this setup?

You’ll need to use an Aux switch with the Blue, but you can definitely put the Blue in the Load box.

Thanks @Bry - that’s helpful. Doing a little bit of additional reading there, it looks like I could also use a 2nd blue switch (my order of 10 just arrived, so it’s easier right now to wire up a 2nd dimmer than to wait for an aux switch to arrive). I haven’t found a great write up of pros-cons to using a 2nd dimmer vs an aux switch. Any thoughts on that? 2nd question: do the aux switches work with blue dimmers (via zigbee association) or are they only Z-wave? EDIT: Third question: any advantages/disadvantages to using other branded aux switches (e.g., GE?)

Yes, you can use two switches. You then need to use Zigbee binding to associate the two switches together. I don’t use binding, so I’m not a good reference on that. To some extent it depends upon your hub, and you can read here about the issues people have encountered.

If you post back with the hub you’re using, I’m sure someone will post back.

Any of the supported aux’s will work just fine, although I have just used an Inovelli Aux with Blues.

EDIT: The Aux switch communicates with the Inovelli switch via the conductor between the Aux switch’s Traveler terminal and the Inovelli Blue’s Traveler terminal. So it is a wired connection.

Thanks again, @Bry - really appreciate the follow-up. I use a Hubitat for my hub.

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I’ve got all my 3-way and 4-way lights using Blue 2-1’s and it’s great. In a 3 way situation, simply bind Switch 1 to Switch 2, then bind Switch 2 to Switch 1. Same goes for a 4-way situation just with binding to an additional switch. Works like a charm.

SOLVED: just following up that I ended up going with an Aux switch with my Blue 2-1. Works great. Could have done binding between two blue switches, too, but went with the cheaper option.

Thanks, Bry and Dan4.

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