Thermostat adapter- 2 Y

[Tigerwind88]

Hi there,

I found there is no C wire in the previous thermostat, so I bought an adapter. However, when I followed the installation video, I found there are 2 Y, one is blue, one is black. My question is which Y should be connected with adapter grey line? I've tried connect with Blue Y, but no power; I've switched to Black Y, no power as well.

Thank you in advance!

[aperezdeleon]

Hi Tigerwind88,

Thanks for reaching out to our community.

Installing a Nest Power Connector can be confusing, especially with a unique system configuration. Don't worry, I'm here to help.

For a successful installation, remember that the power connector should be placed between the HVAC system's control board and your thermostat. Since you have two Y wires in your control board, connect the one directly communicating with your thermostat. You can follow the wire if visible or match the color of the Y wire in your thermostat base.

However, if the colors don't match or you've verified that all wires are connected correctly according to the installation guide but still have no power, I suggest contacting one of our recommended technicians. They can examine your system and determine the best wiring configuration for your Nest power connector installation.

Let me know how it goes.

Regards,
Angel.