Thermostat Setup - No Y or W wire on control board

Below is an explanation of my issue. My AC is requiring the installation of the C-Wire adapter when I go into the control board of the AC unit. I see the below wire diagram which I see XFMR-R, R, XMFR-C, C, G. My AC control panel has R (and a jumper wire to RC), W, Y, and G. My control board does not have W or Y. So I am not sure where I need to connect the W and Y if my control board does not have those. Also, I found my power label, and I see it reads 208/240V, but do not see anywhere that it says “high voltage” like the app says or none of the wires have any “wire nuts”. If my system is a high-voltage system, could I use the following external power source to power the Wyze unit?

G-Drive w/ pictures of wiring and diagrams - Wyze Thermostat - Google Drive

If any further information is needed please let me know.

Suggest you look behind current thermostat.
Take it off the wall and I’m guessing you’ll find a Blue (common) wire tucked inside the wall like mine was. If it is you’re all set assuming it’s connected at the furnace. All furnaces/AC’s are 220volts. Your diagram indicated a 24volt transformer for the thermostat.

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This is your air handler.
There should be another control section for heating and cooling.
All this board does is control the fan. Follow the wires marked R (red) and C (blue) off of this board and you should eventually come up to the thermostat wires and possibly a secondary control board.

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You are a genius, tucked there was the blue wire. So the blue wire would be my C wire?

Yes blue is your Common wire. As other poster indicated it will need to be connected at the furnace control board’s C terminal.

So I found the wire, and it is not connected to the board, but in the board, there is already a wire connected there. I tried to follow the wires to see if there was another board and did not find one. I added new pictures to the G-Drive, thank you for the help.

Multiple wires can be connected to C. Just strip the blue thermostat wire and add it to the other wire that is connected to the blue C wire and wire-nut them all together.

Might also be a good time to vacuum out your blower fan. :slight_smile:

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You can safely have two wires connected to the C terminal. Just make certain the furnace breaker or switch is off first.:wink:

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@speadie thank you both! highly appreciate the help! and yes, did not notice how dirty my unit was lol Will update if things work. :wink:

Great success! It worked, no issues. Thank you @chris1952 and @speadie for the quick and accurate help!

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Happy I could help.

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