I'm looking to wire a Honeywell Lyric T5 to my furnace (I do not have an air conditioner, I do have a humidistat). My current wiring at the thermostat is G,W,Y,R. At the furnace it's G,R,C, and 2 at W, there is a spare wire capped off (same colour as the Y wire at the thermostat).
The humidistat is connected to W and C.
Since I don't have air conditioning can I sub out the Y wire for the C wire I need for the new Lyric? My new set up at the Lyric would be G,W,R,C. The furnace would be G,R,2C,2W. The humidistat would not change.
Thanks for your help.
Best Answer
Yes, you can swap out and reuse the Y wire as a C wire, since you don't have an air conditioner. Or use the capped off wire (that's probably better).
hey're just copper wires, and there's no firm color code anyway. Take photos before you disconnect anything, and consider leaving a note tucked inside the thermostat documenting whatever you came up with.
Check this excellent answer for diagrams: https://diy.stackexchange.com/a/10527/5960
Consider posting photos to SE when asking questions.