Thermostat wiring, Confused on the R and C

First part:

The original R wire coming from the thermostat is going to O in the air handler.
and I have a black wire (not coming from the thermostat wires) going to the R. (relay? )
Where is my new R (from the C-wire adapter) supposed to go?

Second part:
The C is occupied by a black wire, Am I supposed to add or replace the C from the adapter?

Do you have a picture of your thermostat wires? if you have an orange, yellow, or brown wire at the thermostat, then you probably wont need the C adapter.

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Hi @speadie ,

There IS two extra wires not used on the handler side, I’ll check if theres any behind the wall on the thermostat side.

Below is the current full scope of the set up.

IF I do have an extra wire on the thermostat side, what would my wiring process be?


If you’ve got an extra brown wire in the wall, take the brown wire at the furnace side, and strip back a bit from the end and add it to the C terminal, then attach the brown wire to C on your wyze thermostat. Tell it that your old thermostat has the following wires : R:(Red) W:(White) Y:(Blue) C:(Brown) G:(Green)

That’s all I would have to do?

Does it matter that the (R)Red wire is going to “O” terminal on the air handler?
See in the Full scope link in the previous post please.
Also thanks for your input, I didn’t get any notifications that you had answered.

The O terminal on that strip is being used as R after the float switch, so that your air conditioner condenser and thermostat will turn off if your evaporator drain plugs up, to prevent it from flooding the area your air handler is in.