I’m trying to sort out my Thermostat wiring issues. My furnace/air conditioning unit is up in my attic and hard to get to. But I did and I found that the control board only has three wires that come off of it to the thermostat. Wires are: Red Green and white. Power appears to come from a transformer that is mounted on a ceiling joist. I don’t know why, but they connected the ps to the yellow wire that goes down to the T-stat. So, at the t-stat I have yellow going to the C terminal, Red wire to the Rc terminal, White to W1 and Green to G terminal. The Small blue wire is not connected to anything.
Yeah, somethings not right. The yellow Y at your thermostat shouldn’t be going to C but to Y on the control board. Y is for AC which might explain why AC is not working. Did you install the C wire adapter? Can you post more pictures of the wired wyze thermostat and if possible the control board too?
Here’s how you should have hooked up your C wire adapter.
I’m betting you hooked up the A/C compressor wires to the wrong side of the adapter or interrupted the C wiring to the compressor when you installed the adapter.
You have 2 yellow wires. One goes to your thermostat, that one used to be attached to the red wire, and is now attached to the wyze adapter’s screw terminal that is labeled Y. The other one shouldn’t have been attached to anything.
I’m not asking you to do anything with the Y ribbon wire, leave it wire nutted to the red wire that goes to the A/C unit.
Your C wire will have 3 wires in its wire nut - large purple from furnace, small white to A/C, and the C ribbon cable from your wyze adapter. This is normal.