I replaced an existing Honeywell programmable thermostat with a new Z-wave enabled CT101-L thermostat yesterday. All went well, and the C, W, Y, R and G wires found their proper target connectors. The thermostat's working fine, and I'm able to control it remotely. (Haven't tested air-conditioning on account of the deep freeze here in Minnesota, but I'm assuming that's OK).
My question is about an unused brown-colored wire tucked back into the wall. This loops back on itself, and wasn't connected to anything on the old thermostat. I'm not sure where / how to trace this back to the furnace.
What is this wire? Is it an outside temperature / humidity sensor (which would be more than awesome), or just something that's a standard part of the cable (which probably is also good, so I can probably add said sensor). Or does using it somewhere unlock some more thermostat goodness?
Best Answer
It's likely not connected to anything. If you go to the furnace, you'll likely see the cable that goes to the thermostat. You'll also likely see the brown wire either wrapped around the cable, or just not connected to anything.