I've got a new thermostat that needs 24VAC to run. I've seen a few Q&A's on this, I have one specific question.

OK, I removed the plate on my furnace that exposes all the electrical connections, and there's the YWGR terminals, with the appropriate colored wires attached, then there's a "C" terminal, which I assume is the 24VAC common post that I want to tap into, to run power to my thermostat.

BUT... There's a second set of wires running from these terminals to my compressor contactor. There's only two. Red and white. The white wire is attached to the Y terminal (along with the yellow wire from my thermostat), and the red wire is attached to the C terminal. (For the record, this matches up with the diagrams in the furnace manual).

Here's my question: Can I run a second wire from the C terminal to my thermostat, or will I short something out?

Thanks in advance,

Bob

c= common red = hot 24v... I'm asuming your thermostat has no batteries and a common wire is needed for the display,


use a blue wire for the common (typically a blue is included in a 5 wire bundle for most thermostats) attach to C at the transformer and the t-stat