Which one is my C wire?
Bought a house recently. A very old house. With an old furnace and thermostat.
Wanting to upgrade the thermostat to a new smart wifi stat, but I don’t know which one of these is my C wire for the new smart stat.
On the furnace circuit board there is (from right to left B G R Y W2 W1.
On the stat side it seems to be correctly color coded with a ton of “spare” wires in that bundle. Almost looks like the C terminal was removed.
Can anyone help me figure out which wire I should be putting to the C terminal on the new stat?
Thank you!
u/CartelClarke — 7 days ago