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Not C wire. Cool mode is not showing

Community Member


First of all I really want to use the Nest thermostat even though my current thermostat does not have a C wire. I have read for you can use the G wire instead. I had a man come wire The thermostat with the G wire into the common wire and made the same changes on the furnace panel.

I did not test it while he was here because I knew it would take a while for me to figure out how to configure the thermostat using the app. I was able to configure the thermostat but I do not see any cooling mode. I do have a heating. I have attached a picture of my old thermostat wiring in the Nest for reference.

I really want this to work. I did read where I could buy a 24 V wire converter just for the common wire.

Do you think this would work if I wired it back the way the old thermostat was without the C wire? My old thermostat did run down batteries a good bit. Thank you very much for any help.